DE10228323B4 - Cathodic electrodeposition process and microcomponents made by such a process - Google Patents

Abstract

A method of cathodic electrolytic deposition of a metallic material on a substrate in nanocrystalline form having an average grain size of less than 100 nm at a deposition rate of at least 0.05 mm / h, comprising:
Providing an aqueous electrolyte containing ions of the metallic material,
Holding the electrolyte at a temperature in the range of 0 to 85 ° C,
Stirring the electrolyte at a stirring speed in the range from 1 to 750 ml / min / A,
Providing an anode and a cathode in contact with the electrolyte,
Passing one or more cathodic current pulses between the anode and cathode in a time interval, the current flowing in the time interval for a _cathodic-on period of 0.1 to 50 ms, and for a _{cathodic-off time} period of 0 to 500 ms does not flow,
Passing through single or multiple anode current pulses between the cathode and the anode in the time interval, the current being passed through for a ...

Description

Territory of invention

The This invention relates to a method of forming coatings of pure metals, metal alloys or metal matrix composites on a workpiece, which is electrically conductive is or an electrically conductive surface layer contains or forming free-standing supports of nanocrystalline metals, Metal alloys or metal matrix composites by use of pulse electrodeposition. The method uses a drum deposition method for the continuous production of nanocrystalline films of pure Metals, metal alloys or metal matrix composites or a selective deposition (brushing) method, the methods being pulse electrodeposition and a non-stationary anode or cathode. New nanocrystalline metal matrix composites are also disclosed. The invention also relates to a Pulse-deposition method for the production or coating of microcomponents. The invention also refers to microcomponents with grain sizes below 1000 nm.

The new process can be applied to wear-resistant Supports and films of pure metals or alloys of metals, selected from the group of Ag, Au, Cu, Co, Cr, Ni, Fe, Pb, Pd, Pt, Rh, Ru, Sn, V, W and Zn and other alloying elements selected from C, P, S and Si, and metal matrix composites of pure metals or alloys with particle additives such as metal powders, metal alloy powders and Metal oxide powders of Al, Co, Cu, In, Mg, Ni, Si, Sn, V and Zn; Nitrides of Al, B and Si; C (graphite or diamond); Carbides of B, Cr, Bi, Si, W; and organic materials such as PTFE and polymer beads. The selective deposition method is particularly suitable for in situ or outdoor applications, such as such as the repair or preparation of nozzles and molds, turbine blades, Steam generating tubes, Reactor core head breakthroughs of nuclear power plants. The continuous one Separation process is particularly suitable for the production of nanocrystalline Foils, e.g. For magnetic applications. The method can be applied to high strength, equiaxed Microcomponents for use in electronics, biomedicine, telecommunications, used in the automotive, space and consumer applications become.

Description of the state the technology / background of the invention

Nanocrystalline Materials referred to as ultrafine grained materials , nanophase materials or nanometer-sized materials, which average grain sizes smaller or equal to 100 nm are indicated by a number of known Process, including sputtering, laser ablation, Inert gas condensation, high energy ball milling, sol gel deposition and electrodeposition. Electrodeposition provides the ability a big Number of high density metals and metal alloy compositions at high production speeds and low capital investment requirements in a single synthesis step.

Of the The prior art primarily describes the use of pulse electrodeposition for the production of nanocrystalline materials.

Erb describes in US 5,352,266 (1994) and in US 5,433,797 (1995) describe a process for producing nanocrystalline materials, in particular nanocrystalline nickel. The nanocrystalline material is electrodeposited on a cathode in an aqueous acidic electrolytic cell by applying a pulsed direct current. The cell optionally also contains voltage lowering means. The products of the invention include abrasion resistant layers, magnetic materials, and hydrogen generation catalysts.

Mori describes in US 5,496,463 (1996) a method and apparatus for composite electroplating of a metallic material comprising SiC, BN, Si ₃ N ₄ , WC, TiC, TiO ₂ , Al ₂ O ₃ , ZnB ₃ , diamond, CrC, MoS ₂ , coloring materials, Polytetrafluoroethylene (PTFE) and microcapsules contains. The solid particles are introduced into the electrolyte in a fine form.

Adler describes in US 4,240,894 (1980) discloses a drum plater for electrodeposited Cu film production. Cu is plated on a rotating metal drum which is partially immersed and rotates in a copper plating solution. The copper foil is peeled from the drum surface, which emerges from the electrolyte, which is plated with electroformed Cu. The rotational speed of the Trom The current and amperage are used to set the desired thickness of the copper foil. The copper foil peeled off from the drum surface is subsequently washed and dried and wound into a suitable coil.

Icxi reveals in US 2,961,395 (1960) describe a method of electroplating an article without the need to sink the surface being treated into a separation tank. The hand-operated applicator serves as the anode and supplies chemical solutions to the metal surface of the workpiece to be plated. The workpiece to be plated serves as a cathode. The hand applicator anode with the mesh containing the electrolyte and the workpiece cathode are connected to a DC power source to produce a metal layer on the workpiece by passing a DC current.

The document EP 0 670 916 B1 describes a method for the electrochemical deposition of metallic material in nanocrystalline form, wherein the process parameters electrolyte temperature, maximum current density and current pulse durations are specified for the deposition of material with a grain size of less than 100 nm of a cathode. Optionally, the electrolyte used may also be agitated, at least according to one embodiment of the process described therein.

The Document WO 00/28114 A1 describes a method for depositing nanocrystalline Particles of a catalytic material on a substrate below Use of electrolytic deposition using Pulse current with duty cycles of cathodic pulses of less than 40% and a pulse frequency range of 10 Hz to 5000 Hz.

Micromechanical Systems (MEMS) are machines that are constructed of small, moving and stationary Parts having an overall dimension ranging from 1 to 1000 μm, e.g. for use in electronics, biomedicine, telecommunications, Automotive, space and consumer technologies.

Such Components are e.g. produced by photoelectro impression, which is an additive process in which powder is deposited in layers be to the desired Structure, e.g. laser enhanced electroless deposition to build. Lithography, electro-casting and casting (LIGA) and other photolithography related methods are used to obtain aspect ratio (part height to width) to overcome problems in question. Other techniques used include silicon micromachining by mask plating and microcontact printing.

Summary:

It It is an object of the invention to provide a reliable and flexible method for cathodic electrolytic deposition for forming coatings or freestanding deposits of nanocrystalline metals, metal alloys or metal matrix composites.

It Another object of the invention is to provide microcomponents with clarity improved property-dependent resistance and tailor made desired Properties for to provide improved microsystems in the overall performance.

preferred embodiments of the invention are defined in the respective dependent claims.

The present invention provides a pulse deposition method which consists of a single cathodic on-time or multiple cathodic on-times of different current densities and single or multiple off-times per time interval. Periodic pulse reversal, a bipolar waveform that alternates between cathodal pulses and anodic pulses, may optionally also be used. The cathodic pulses may be inserted into the waveform before, after or between the on pulses and / or before, after or in the off time. The anodic pulse current density is generally equal to or greater than the cathodic current density. The anodic charge (Q _anodic ) of the "backward pulse" per time interval is always smaller than the cathodic charge (Q _cathodic )

The on times of cathodic pulses range from 0.1 to 50 ms (1-50), off times from 0 to 500 ms (1-100), and anodic pulse times range from 0 to 50 ms, preferably from 1 to 10 ms. The work cycle, expressed as the cathodic on times divided by the sum of the cathodic on times, the off times and the anodic times ranges from 5 to 100%, preferably from 10 to 95%, and more preferably from 20 to 80%. The frequency of the cathodic pulses ranges from 1 Hz to 1 kHz, and more preferably from 10 Hz to 350 Hz.

Nanocrystalline coatings or free-standing deposits of metallic materials are obtained by varying process parameters such as current density, duty cycle, workpiece temperature, coating solution temperature, solution recycle rates, over a wide range of conditions. The following list describes suitable operating parameter ranges for carrying out the invention:
Average current density (if determinable, anodic or cathodic): 0.01 to 20 A / cm ² , preferably 0.1 to 20 A / cm ² , more preferably 1 to 10 A / cm ²
Duty cycle 5 to 100%
Frequency: 0 to 1000 Hz
Electrolytic solution temperature: -20 to 85 ° C
Electrolyte solution recirculation / agitation rates: ≤ 10 liters per minute per cm ^{2 of} anode or cathode area (0.0001 to 10 l / min, cm ² )
Workpiece temperature: -20 to 45 ° C
Anode vibration rate: 0 to 350 cycles / min
Linear velocity anode to cathode: 0 to 200 m / min (brush) 0.003 to 0.16 m / min (drum).

The The present invention preferably provides a method for Deposition of nanocrystalline metals, metal matrix composites and Microcomponents with deposition rates of at least 0.05 mm / h, preferably at least 0.075 mm / h, and more preferably at least 0.1 mm / h.

In In the process of the present invention, the electrolyte may be preferred by means of pumps, whirring or ultrasonic excitation at speeds from 1 to 750 ml / min / A (ml solution per minute per ampere average current passed), preferably at rates of 1 to 500 ml / min / A.

In The process of the present invention may optionally include a grain refiner or a stress relief agent added to the electrolyte, selected from the group of saccharin, coumarin, sodium lauryl sulfate and thio-urea.

This invention provides a method of depositing nanocrystalline metal matrix composites on a permanent or temporary substrate, optionally containing at least 5% by volume of particulate matter, preferably 10% by volume of particulate matter, more preferably 20% by volume. % of particulate matter, more preferably 30 vol% of particulate matter, and most preferably 40 vol% of particulate matter, for applications such as hard topcoats, projectile-truncated armor, valve freshener, valved and valved Rotary tool coatings, energy absorbing armor plates, noise reduction systems, connectors to piping joints, eg used in oil drilling applications, refurbishment of roller bearing axles in the railway industry, computer chips, repair of electric motor and generator parts, repair of grooves in pressure rollers, using tank, drum -, frame, selective (eg Bür trap deposition) and continuous (eg drum deposition) deposition processes using pulse electrodeposition. The particulate matter may be selected from the group of metal powders, metal alloy powders and metal oxide powders of Al, Co, Cu, In, Mg, Ni, Si, Sn, V and Zn; Nitrides of Al, B and Si; C (graphite or diamond), carbides of B, Bi, Cr, Si, W; MoS ₂ ; and organic materials such as PTFE or polymer beads. The average particle size of the particulates is typically below 10 microns, preferably below 1000 nm (1 micron), preferably 500 nm, and more preferably below 100 nm.

The process of this invention optionally provides a process for continuous (drum or belt) deposition of nanocrystalline films optionally containing solid particles in solution selected from metal powders, metal alloy powders and metal oxide powders of Al, Co, Cu, In, Mg, Ni, Si, Sn , V and Zn; Nitrides of Al, B and Si; C (graphite or diamond); Carbides of B, Bi, Si, W; MoS ₂ , and organic materials such as PTFE and polymer beads to impart desired properties including hardness, wear resistance, lubrication, magnetic properties. The drum or belt provides a temporary substrate from which the plated film can be easily and continuously removed.

According to a preferred embodiment of the invention, it is also possible to produce nanocrystalline layers by electrodeposition without the need to place the article to be coated in Submerge coating bath. Brush or tampon deposition is a suitable alternative to tank deposition, especially if only a portion of the workpiece is to be plated, without the need to mask areas that are not to be plated. The brush deposition apparatus typically employs a dissolvable or dimensionally stable anode that is wound into an absorbent spacer felt to form the anode brush. The brush is rubbed against the surface to be plated, in a manual or mechanized manner, and an electrolyte solution containing ions of the metal or metal alloys to be plated is injected into the spacer felt. Optionally, this solution also contains solid particles in solution selected from metal powders, metal alloy powders and metal oxide powders of Al, Co, Cu, In, Mg, Ni, Si, Sn, V and Zn; Nitrides of Al, B and Si; C (graphite or diamond); Carbides of B, Bi, Si, W; MoS ₂ , and organic materials such as PTFE and polymer beads to impart desired properties, including hardness, wear resistance, lubrication.

in the Case of drum, belt or brush deposition ranges the relative movement between anode and cathode from 0 to 600 meters per minute, preferably from 0.003 to 10 meters per minute.

in the Methods of this invention may Microcomponents for Microsystems, including micromechanical systems (MEMS) and micro-optical systems, with Grain sizes equal or less than 1000 nm. The maximum dimension of the microcomponent part is equal to or less than 1 mm, and the ratio between the maximum outer dimension of the microcomponent part and the average grain size is the same or greater than 10, preferably greater than 100th

The Microcomponents of the present invention preferably have one equiaxed microstructure over the plated component, which is relatively independent of the thickness and the Structure of the component is.

It Another aspect of the present invention is microcomponents be provided, in which the average grain size a Magnitude smaller than the outer dimension of the part, whereby a high degree of strength is obtained.

The Microcomponents according to this Invention have a significantly improved property-dependent resistance and improved customized desired Properties of MEMS structures for in their overall performance improved microsystems through preferred equiaxed electrodepositions, which exclude the fine grain of columnar grain transition in the microcomponent, and at the same time reducing the grain size of the deposits below 1000 nm.

Preferred embodiments the invention:

Other Features and advantages of this invention will become clearer in the following detailed description and examples of the preferred embodiments of the invention, together with the attached schematic drawings, in which:

1 a cross-sectional view of a preferred embodiment of a drum-separating device shows;

2 a cross-sectional view of a preferred embodiment of a brush-separating device shows; and

3 a top view of a mechanized moving means for generating a mechanized stroke of the anode brush shows.

1 schematically shows a separation tank or container 1 that with an electrolyte 2 is filled, which contains the ions of the metallic material to be plated. Partially immersed in the electrolyte is the cathode in the form of a rotating drum 3 , which are electrically connected to a power source 4 connected is. The drum is rotated by an electric motor (not shown) via a belt drive and the rotational speed is variable. The anode 5 may be a plate or a custom anode, as shown, which is electrically connected to the power source 4 connected is. Three different anode arrangements can be used: matched anodes, as in 1 shown which contour of the submerged portion of the drum 3 Follow, vertical anodes, attached to the walls of the tank 1 are positioned, and horizontal anodes at the bottom of the tank 1 are positioned. In the case of a slide 16 made of metallic material, wel ches on the drum 3 Electrodeposited, the film becomes 16 from the drum surface, which consists of the electrolyte 2 emerges, pulled, which is covered with the electro-formed metallic material.

2 schematically shows a workpiece to be plated 6 connected to the negative output of the power source 4 connected is. The anode 5 includes a handle 7 , with a conductive anode brush 8th , The anode contains channels 9 for supplying the electrolyte solution 2 from a temperature-controlled tank (not shown) to the anode mesh (absorbent spacer) 10 , That of the absorbent spacer 10 Dripping electrolyte is optional in a dish 11 collected and returned to the tank. The absorbent spacer 10 which is the electrolyte 2 contains, the anode brush isolated 8th also electrically from the workpiece 6 and sets the distance between anode 5 and cathode 6 one. The anode brush handle 4 can over the workpiece 6 be moved manually during the deposition process, alternatively, the movement may be motorized, as in 3 shown.

3 schematically shows a wheel 12 which is driven by an adjustable speed motor (not shown). A cross-arm 13 can rotate (axis of rotation A) to the rotating wheel 12 at different positions x at a slot 14 be attached with a bushing and an adjusting screw (not shown) to produce a desired stroke or stroke. The stroke length can be adjusted by the position x (radius), in which the axis of rotation A of the transversely movable arm at the slot 14 is attached. In 3 is the transversely moving arm 13 shown to be in a non-hub, neutral position with the axis of rotation A in the center of the wheel 12 is. The transversely moving arm 13 has a second pivot axis B which is defined by a bearing (not shown) slidable in a guideway 15 is appropriate. When the wheel 12 turns, causes the rotation of the transversely movable arm 13 about axis A at position x the transversely movable arm 13 , in the guideway 15 to move back and forth and to pivot about axis B. An anode 5 which have the same characteristics as in 2 is shown on the transversely movable arm 13 attached, and moves over the workpiece 6 in a movement that depends on the position x. Usually the movement has the shape of the number 8. The anode 5 and the workpiece 6 are respectively connected to positive and negative outputs of the power source (not shown). The kinematic ratio is very similar to that of a steam engine.

These Invention relates to the production of nanocrystalline coatings, Films and microsystem components by pulse electrodeposition. Optionally, solid particles are dissolved in the electrolyte and become inserted into the deposit.

Nanocrystalline Coatings for Abrasion-resistant applications are nowadays aimed at increasing Wear resistance by raising the hardness and reducing the coefficient of friction by grain size reduction Below 100 nm. It has now been found that a contribution of sufficient Volume fraction of hard particles, the wear resistance of nanocrystalline materials.

The material properties can also be changed by, for example, the addition of lubricants (such as MoS ₂ and PTFE). In general, the particulates selected from the group of metal powders, metal alloy powders and metal oxide powders may be selected from Al, Co, Cu, In, Mg, Ni, Si, Sn, V, and Zn; Nitrides of Al, B and Si; C (graphite and diamond), carbides of B, Bi, Si, W; MoS ₂ and organic materials such as PTFE and polymer spheres.

example 1

Nanocrystalline NiP-B ₄ C nanocomposites were deposited on Ti and unalloyed steel cathodes immersed in a modified Watts bath for nickel, using a soluble anode made of a nickel plate and a Dynatronix (Dynanet PDPR 20). 30-100) -Pulsstromversorgung. The following conditions were used:
Anode / anode area: Soluble anode: Ni plate, 80cm ²
Cathode / cathode surface: Ti or unalloyed steel plate / approx. 5cm ²
Cathode: firm
Anode: fixed
Linear velocity anode to cathode: not applicable
Average cathodic current density: 0.06A / cm ²
t _cathodic-on / t _cathodic-off : 2ms / 6ms
Frequency: 125 Hz
Duty cycle: 25%
Deposition time: 1 hour
Deposition rate: 0.09 mm / h
Electrolyte temperature: 60 ° C
Electrolyte recirculation speed: vigorous stirring (mechanical bidirectional impeller)
Basic Electrolyte Formulation:
300g / l NiSO ₄ x 7H ₂ O
45g / l NiCl ₂ x 6H ₂ O
45g / l H ₃ BO ₃
18 g / l H ₃ PO ₄
0.5-3 ml / L of interface active substance to a surface tension of <30 dynes / cm
0-2g / l sodium saccharinate
360 g / l boron carbide, 5μm average particle diameter
pH 1.5-2.5.

The hardness values of metal matrix composites, which have a nanocrystalline matrix structure, are typically twice as high as conventional coarse-grained metal matrix composites. In addition, the hardness and wear properties of nanocrystalline NiP-B ₄ C composites containing 5.9 wt% P and 45 vol% B ₄ C are compared with those of pure coarse-grained Ni, pure nanocrystalline Ni and electro-deposited Ni -P of an equivalent chemical composition in the attached table. The material hardening is controlled by Hall-Petch grain size enhancement, while the abrasion wear resistance is simultaneously optimized by incorporation of B ₄ C particles. Table: NiP-B ₄ C nanocomposite properties

Example 2

Nanocrystalline Co-based nanocomposites were deposited on titanium and unalloyed steel cathodes immersed in a cobalt-modified Watts bath, using a soluble anode made from a cobalt plate, and a Dynatronics (Dynanet PDPR 20-30). 100) -Pulsstromversorgung. The following conditions were used:
Anode / anode area: soluble anode (co-plate) / 80cm ²
Cathode / cathode surface: Ti (or unalloyed steel) panel / approx. 6,5cm ²
Cathode: firm
Anode: fixed
Linear velocity anode to cathode: not applicable
Cathodic peak current density: 0.100 A / cm ²
Anodic peak current density: 0.300 A / cm ²
Cathodic t _cathodic-on / t _cathodic-off / anodic t _anodic-on (t _anodic ): 16ms / 0ms / 2ms
Frequency: 55.5 Hz
Cathodic duty cycle: 89%
Anodic duty cycle: 11%
Deposition time: 1 h
Deposition rate: 0.08 mm / h
Electrolyte temperature: 60 ° C
Electrolyte recirculation rate: 0.15 liter / min / cm ² cathode area (no pump flow; stir)
Electrolyte Formulation:
300 g / l CoSO ₄ × 7H ₂ O
45 g / l CoCl ₂ × 6H ₂ O
45 g / l H ₃ BO ₃
2 g / l C ₇ H ₄ NO ₃ SNa sodium saccharinate
0.1 g / l C ₁₂ H ₂₅ O ₄ SNa sodium lauryl sulfate (SLS)
100 g / l SiC, <1 μm average particle diameter
pH 2.5

In the attached table, the hardness and abrasion properties of a nanocrystalline Co-SiC composite containing 22 vol.% SiC are compared with those of pure coarse Co and pure nanocrystalline Co. Hall Petch grain size enhancement controls material hardening, while abrasion wear resistance Resistance is optimized at the same time by the admixture of a material consisting of SiC particles. Table: Co-nanocomposite properties

Continuous deposition has been carried out to produce films, for example using drum depositions of nanocrystalline films containing optionally solid particles in solution selected from pure metals or alloys of pure metals or alloys with particulate additives such as metal powders, metal alloy powders and Metal oxide powders of Al, Co, Cu, In, Mg, Ni, Si, Sn, V, and Zn; Nitrides of Al, B and Si; C (graphite or diamond); Carbides of B, Bi, Si, W; and organic materials such as PTFE and polymer beads to impart desired properties including hardness, wear resistance, lubrication, magnetic properties. Nanocrystalline metal foils were deposited on a rotating Ti drum partially immersed in a deposition electrolyte. The nanocrystalline film was cathodically electro-formed on the drum using a soluble anode made of a titanium container filled with an anode metal and using a pulse power supply. For alloy sheet fabrication, a stream of additional cations at a predetermined concentration was continuously added to the electrolyte solution to establish an equilibrium state concentration of the alloying cations in solution. For metal and alloy foil production, containing matrix composites, a stream of the composite additive was added to the deposition bath at a predetermined rate to establish an equilibrium content of the additive. Three different anode arrangements may be used: conformal anodes following the contour of the submerged portion of the drum, vertical anodes positioned on the walls of the container, and horizontal anodes positioned at the bottom of the container. Films were made at average cathodic current densities ranging from 0.01 to 5 A / cm ^2, and preferably from 0.05 to 0.5 A / cm ² . The rotational speed was used to adjust the film thickness, and this speed ranged from 0.003 to 0.15 rpm (or 20 to 1000 cm / h), and preferably from 0.003 to 0.05 rpm (or 20 to 330 cm / h).

Example 3: Metal matrix composite drum deposition

Nanocrystalline Co-based nanocomposites were deposited on a rotating Ti drum as described in Example 2 immersed in a cobalt-modified Watts bath. The nanocrystalline film, 15 cm wide, was cathodically electro-formed on the drum using a soluble cobalt anode contained in a Ti wire basket and a Dynatronix (Dynanet PDPR 20-30-100) pulse power supply. The following conditions were used:
Anode / anode area: conformable soluble anode (co-pieces in Ti basket) / not determined
Cathode / cathode surface: Ti 600cm ²
Cathode: turning
Anode: fixed
Linear velocity anode vs. cathode: 0.018 rpm
Average current density: 0.075 A / cm ²
Cathodic peak current density: 0.150 A / cm ²
Anodic peak current density: not applicable
Cathodic t _cathodic-on / t _cathodic-off / anodic t _an (t _anodic-on ): 1 ms / 1 ms / 0 ms
Frequency: 500 Hz
Cathodic duty cycle: 50%
Anodic duty cycle: 0%
Deposition time: 1 h
Deposition rate: 0.05 mm / h
Electrolyte temperature: 65 ° C
Electrolyte recirculation rate: 0.15 liter / min / cm ² cathode area (no pump flow; stir)
Electrolyte Formulation:
300 g / l CoSO ₄ × 7H ₂ O
45 g / l CoCl ₂ × 6H ₂ O
45 g / l H ₃ BO ₃
2 g / l C ₇ H ₄ NO ₃ SNa sodium saccharinate
0.1 g / l C ₁₂ H ₂₅ O ₄ SNa sodium lauryl sulfate (SLS)
5 g / l phosphorous acid
35 g / l SiC, <1 μm mean particle diameter
5 g / l dispersant
pH 1.5

The Co / P-SiC foil has a grain size of 12 nm, a hardness of 690 VHN containing 1.5% P and 22% by volume SiC.

Example 4

Nanocrystalline nickel-iron alloy foils were deposited on a rotating Ti drum which was partially submerged in a modified Watts bath for nickel. The nanocrystalline film, 15 cm wide, was electro-formed cathodically on the drum using a soluble anode made of a titanium wire basket filled with Ni round stock and a Dynatronics (Dynanet PDPR 50-250-750) pulse power supply. The following conditions were used:
Anode / anode surface: adapted soluble anode (Ni round pieces in a metal cage) / indefinite
Cathode / Cathode Area: Submerged Ti-drum / about 600 cm ²
Cathode: rotating at 0.018 rpm (or 120 cm / h)
Anode: fixed
Linear velocity anode to cathode: 120 cm / h
Average cathodic current density: 0.07 A / cm ²
t _cathodic-on / t _cathodic-off 2 ms / 2ms
Frequency: 250 Hz
Duty cycle: 50%
Production time: 1 day
Deposition rate: 0.075 mm / h
Electrolyte temperature: 60 ° C
Electrolyte recirculation rate: 0.15 liter / min / cm ² cathode area
Electrolyte Formulation:
260 g / l NiSO ₄ .7H ₂ O
45 g / l NiCl ₂ × 6H ₂ O
12 g / l FeCl ₂ X 4 H ₂ O
45 g / l H ₃ BO ₃
46 g / l sodium citrate
2 g / l sodium saccharinate
2.2 ml / l NPA-91
pH 2.5
Iron linefeed formulation:
81 g / l FeSO ₄ .7H ₂ O
11 g / l FeCl ₂ .4H ₂ O
13 g / l H ₃ BO ₃
9 g / l sodium citrate
4 g / LH ₂ SO ₄
0.5 g / l sodium saccharinate
pH 2.2
Speed of addition: 0.3 l / h
Composition: 23-27% by weight Fe
Average grain size: 15 nm
Hardness: 750 Vickers

selective or brushing off is a portable method for selective deposition of localized surfaces on a workpiece, without submerging the article in a separation tank. There are thereby clear differences between selective deposition and Tank and Drum Separator Applications. In the case of selective deposition it is difficult to see the cathode surface to determine exactly, and therefore the cathodic current density and / or Peak current density changeable and generally unknown. The anodic current density and / or Peak current density can be determined, provided that that the same anode area while of the deposition operation, e.g. in the case of flat anodes. In the case of shaped anodes, the anode area can not be determined exactly e.g. change in the case of a molded anode and a shaped cathode the "effective" anode area too while the deposition process. Selective deposition is performed by Movement of the anode surrounded by an absorbent spacer mesh is and contains the electrolyte, back and forth about that Workpiece, which is typically done by an operator, until the desired Total area the required thickness is coated.

selective Separation techniques are particularly suitable for repair and for refurbishing articles, as the brush separator assemblies are transportable are easy to operate, and do not require decomposition of the system, which contains the workpiece to be plated. Brush separation also allows the deposition of parts too large to be immersed in separation tanks are. Bürstenabscheiden is used to provide coatings for improved corrosion resistance, improved wear, improved appearance (decorative Depositing) and it can be used to worn or misshapen Recover parts. Bürstenabscheidesysteme and separation solutions are commercially available, e.g. from Sifco Selective Plating, Cleveland, Ohio, who also mechanized and / or automated tooling for use in production operations huge Scope offers. The deposition tools used include the Anode (DSA or soluble), surrounded by an absorbent, an electrically non-conductive material and an insulated handle. In the case of DSA anodes, anodes are typical Herge is made from graphite or Pt-coated titanium and they can be agents contained for regulating the temperature by means of a heat exchanger system. For example, the electrolyte used can be heated or cooled and passed through the anode be to the desired Maintain temperature range. The absorbent spacer material contains and distribute the electrolyte solution between the anode and the workpiece (cathode), prevents short circuits between Anode and cathode and brushes against the surface the surface to be plated. This mechanical friction or brush movement, which on the workpiece while of the deposition process affects the quality and the surface finish the coating and allows fast deposition rates. Selective-precipitating electrolytes are formulated to be acceptable Coatings over to produce a wide temperature range, which of low, about -20 ° C up to 85 ° C enough. Because the workpiece often is great compared to the area, which is coated, selective deposition is often on workpiece applied at ambient temperature, ranging from low, about -20 ° C to about high 45 ° C. Unlike "typical" Elektroabscheidevorgänge can in the case of selective deposition, the temperature of the anode, the Cathode and the electrolyte vary significantly. Salting out of Electrolyte components can occur at low temperatures and the electrolyte may be reheated periodically or continuously Need to become, around all the precipitated ones Dissolve chemicals.

A Sifco brush separator unit (model 3030 - 30 A max.) Was set up. The graphite anode tip was inserted into a cotton bag spacer and either attached to a mechanized, transversely movable arm to create the "brushing motion", or manually moved by an operator back and forward over the workpiece, or as otherwise indicated. The anode assembly was soaked in the deposition solution and the coating was deposited by brushing the deposition tool against the cathodically charged working surface composed of various substrates. A peristaltic pump was used to feed the electrolyte at predetermined rates into the brushing tool. The electrolyte was allowed to drip from the workpiece into a tray which also served as a "settling solution reservoir" from which it was returned to the electrolyte tank. The anode had flow holes / channels in the bottom surface to ensure good electrolyte distribution and good electrolyte / workpiece contact. The anode was attached to a transversely movable arm and the circular motion was adjusted to allow uniform strokes of the anode with respect to the substrate surface. The rotational speed was adjusted to increase or decrease the relative anode / cathode travel speed as well as the anode / substrate contact time at any single location. Brush deposition was normally carried out at a rate of about 35-175 oscillations per minute, at a rate of 50-85 oscillations per minute, which is optimal. Electrical contacts were made on the brush handle (anode) and directly on the workpiece (cathode). Coatings were deposited on a number of substrates, including Kup fer, 1018 low carbon steel, 4130 high carbon steel, 304 stainless steel, a 2.5 inch (6.35 cm) outside diameter steel tube, and a weld covered I625 tube. The cathode size was 8 cm ² except the 2.5 inch outer diameter steel tube where a 3 cm wide strip was exposed around the outer diameter and the weld-covered I625 tube on which a damage repair operation was performed.

A Dynatronics Programmable Pulse Traction Power Supply (Dynanet PDPR 20-30-100) was used.

From Sifco provided standard substrate cleaning and activation procedures uses.

Example 5:

Nanocrystalline pure nickel was deposited on an 8 cm ² area electrode with a 35 cm ² anode using the described removal. Usually, the workpiece has a much larger area than the anode. In this example, a workpiece (cathode) was chosen to be substantially smaller than the anode to ensure that the oversized anode, while kept constantly moving, always covered the entire workpiece to allow determination of the cathode current density. Since a non-soluble anode was used, NiCO _{3 was} periodically added to the deposition bath to maintain the desired Ni ²⁺ concentration. The following conditions were used:
Anode / anode surface: graphite / 35 cm ²
Cathode / cathode surface: unalloyed steel / 8 cm ²
Cathode: stationary
Anode: mechanically oscillated with 50 oscillations per minute
Linear velocity anode to cathode: 125 cm / min
Average cathodic current density: 0.2 A / cm ²
t _cathodic-on / t _cathodic-off : 8 ms / 2 ms
Frequency: 100 Hz
Duty cycle: 80%
Deposition time: 1 h
Deposition rate: 0.125 mm / h
Electrolyte temperature: 60 ° C
Electrolyte recirculation rate: 10 ml of solution per minute per cm ^{2 of} anode area or 220 ml of solution per minute per amp of average current passed
Electrolyte Formulation:
300 g / l NiSO ₄ .7H ₂ O
45 g / l NiCl ₂ × 6H ₂ O
45 g / l H ₃ BO ₃
2 g / l sodium saccharinate
3 ml / l NPA-91
pH 2.5
Average grain size: 19 nm
Hardness: 600 Vickers

Example 6:

Nanocrystalline Co was deposited using the same structure described under the following conditions:
Anode / anode surface: graphite / 35 cm ²
Cathode / cathode surface: unalloyed steel / 8 cm ²
Cathode: stationary
Anode: mechanically oscillated with 50 oscillations per minute
Linear velocity anode to cathode: 125 cm / min
Average cathodic current density: 0.10 A / cm ²
t _cathodic-on / t _cathodic-off 2 ms / 6 ms
Frequency: 125 Hz
Duty cycle: 25%
Deposition time: 1 h
Deposition rate: 0.05 mm / h
Electrolyte temperature: 65 ° C
Electrolyte recirculation rate: 10 ml of solution per minute per cm ^{2 of} anode area or 440 ml of solution per minute per amp of average current passed
Electrolyte Formulation:
300 g / l NiSO ₄ .7H ₂ O
45 g / l NiCl ₂ 6H ₂ O
45 g / l H ₃ BO ₃
2 g / l sodium saccharinate
0.1 g / l C ₇ H ₄ NO ₃ Sna Sodium Lauryl Sulfate (SLS)
pH 2.5
Average grain size: 13 nm
Hardness: 600 Vickers

Example 7:

Nanocrystalline Ni / 20% Fe was deposited using the previously described construction. A 1.5 inch (3.81 cm) wide tape was plated on the outside diameter of a 2.5 inch (6.35 cm) tube by rotating the tube along its longitudinal axis while maintaining a solid anode under the following conditions anode / anode area / effective anode area: graphite / 35 cm ² / undetermined cathode / cathode area: 2.5 inch (6.35 cm) outer diameter steel tube made of 2101A1 carbon steel / undetermined
Cathode: rotating at 12 rpm
Anode: stationary
Linear velocity anode to cathode: 20 cm / min
Average cathodic current density: indefinite
Permitted total current: 3.5 A
t _cathodic-on / t _cathodic-off 2 ms / 6 ms
Frequency: 125 Hz
Duty cycle: 25%
Deposition time: 1 h
Deposition rate: 0.05 mm / h
Electrolyte temperature: 55 ° C
Electrolyte recirculation rate: 0.44 L of solution per minute per amp passed
Electrolyte Formulation:
260 g / l NiSO ₄ .7H ₂ O
45 g / l NiCl ₂ × 6H ₂ O
7.8 g / l FeCl ₂ .4H ₂ O
45 g / l H ₃ BO ₃
30 g / l Na ₃ C ₆ H ₅ O ₇ .2H ₂ O sodium citrate
2 g / l sodium saccharinate
1 ml / l NPA-91
pH 3.0
Average grain size: 15 nm
Hardness: 750 Vickers

Example 8:

A defect (notch) in a welded tube section was filled with nanocrystalline Ni using the same construction as in Example 1. The notch was about 4.5 cm long, 0.5 cm wide and had an average depth of about 0.175 mm, although the rough finish of the defect made it impossible to determine its exact surface area. The area surrounding the defect was covered, and Nano Ni was deposited on the defect surface until its original thickness was restored.
Anode / anode surface: graphite / 35 cm ²
Cathode / Cathode area: I625 / indeterminate
Cathode: stationary
Anode: mechanically oscillated with 50 oscillations per minute
Linear velocity anode to cathode: 125 cm / min
Average cathodic current density: indefinite
t _cathodic-on / t _cathodic-off 2 ms / 6 ms
Frequency: 125 Hz
Duty cycle: 25%
Deposition time: 2 h
Deposition rate: 0.087 mm / h
Electrolyte temperature: 55 ° C
Electrolyte recirculation rate: 0.44 liters of solution per minute per ampere of average current transmitted
Electrolyte Formulation:
300 g / l NiSO ₄ .7H ₂ O
45 g / l NiCl ₂ × 6H ₂ O
45 g / l H ₃ BO ₃
2 g / l sodium saccharinate
3 ml / l NPA-91
pH 3.0
Average grain size: 20 nm
Hardness: 600 Vickers

Microcomponents having dimensions of less than 1000 μm (1 mm) in all are becoming increasingly important for use in electronic, biomedical, telecommunications, automotive, space and consumer applications. Metallic macrosystem components having a maximum overall dimension of from 1 cm to over 1 m, which contain conventional grain size materials (1-1000 μm) exhibit a ratio of maximum dimension to grain size ranges of 10 to 10 ⁶ . This number reflects the number of grains over the maximum part dimension. When the maximum size of the component is reduced to less than 1 mm using conventional grain size material, the component may potentially be made from only a few grains, or a single grain, and the ratio between the maximum dimension of the microcomponent and the grain size ranges is addressed 1. In other words, a single or a few grains extend along the entire part, which is undesirable. To increase component reliability of microcomponents, the ratio of maximum component size to grain size ranges must be increased above 10 by using a more granular material, as this class of material typically exhibits grain size values 10 to 10,000 times smaller than those of conventional materials.

For conventional LIGA and other plated microcomponents begin electrodeposition initially with a fine grain size at the Substrate material. With increasing deposition thickness in the growth direction becomes ordinary the transition to columnar grains observed. The thickness of the columnar grains is sufficient typically from a few to a few tens of microns while their Some length Can reach hundreds of microns. The consequence of such Structures is the development of anisotropic properties with increasing deposition thickness, and achieving a critical Thickness, in which only a few grains the entire cross section cover the components, with widths below 5 to 10 microns. Another Waste in the thickness of a component leads to a bamboo structure, which leads to a significant loss in strength. Therefore is the microstructure of electro-deposited microcomponents which currently in use, completely inappropriate regarding Property requirements across both the width and the Thickness of component based on grain shape and average Grain size.

So far were parts made of conventional grain size materials which were known to have serious reliability issues mechanical properties such as Young's modulus, Limit tensile strength, fatigue strength and to suffer creeping behavior, they are known to be extremely sensitive On processing parameters are related to the structure of these components are connected. Many of the problems encountered were caused by Inappropriate scaling of major microstructure features (i.e. Grain size, grain shape, Grain orientation) with the outer size of the component, which is too unusual Property variations resulted, which are usually the same for macroscopic components Material were not observed.

Example 9:

Metal microfeather fingers are used to contact IC chips with high pad count and density, and to transport energy and signals to and from the chips. The springs offer high value-maintaining electrical contacts for a variety of interconnect structures, including chip-scaled semiconductor packages, high density interconnect connectors, and sensor contacts. The solid parallel interlayer structures and assemblies enable high speed testing of separate integrated circuit components fixed on a compliant carrier, and allow ben test electronics to be located in close proximity to the integrated circuit components under test.

The micro-spring fingers require high resistance to deformation and ductility. A 25 μm nanocrystalline Ni layer was deposited on 500 μm gold plated CrMo fingers using the following conditions:
Anode / anode area: Ni / 4.5 × 10 ^-3 cm ²
Cathode / Cathode area: gold plated CrMo / about 1 cm ²
Cathode: stationary
Anode: stationary
Linear velocity anode to cathode: 0 cm / min. Average cathodic current density: 50 mA / cm ²
t _cathodic-on / t _cathodic-off : 10 ms / 20 ms
Frequency: 33 Hz
Duty cycle: 33%
Deposition time: 120 minutes
Deposition rate: 0.05 mm / h
Electrolyte temperature: 60 ° C
Electrolyte recirculation rate: none
Electrolyte Formulation:
300 g / l NiSO ₄ .7H ₂ O
45 g / l NiCl ₂ × 6H ₂ O
45 g / l H ₃ BO ₃
2 g / l sodium saccharinate
3 ml / l NPA-91
pH 3.0
Average grain size: 15-20 nm
Hardness: 600 Vickers

The Nanofinger showed a significantly higher contact force compared with fingers "conventional Grain size ".

Claims (25)

A method of cathodic electrolytic deposition of a metallic material on a substrate in nanocrystalline form having an average grain size of less than 100 nm at a deposition rate of at least 0.05 mm / h, comprising: providing an aqueous electrolyte containing ions of the metallic material; Holding the electrolyte at a temperature in the range of 0 to 85 ° C, - stirring the electrolyte at a stirring speed in the range of 1 to 750 ml / min / A, - providing an anode and a cathode in contact with the electrolyte, - passing single or multiple cathode current pulses between the anode and cathode in a time interval, the current flowing in the time interval for a T _cathodic-on period of 0.1 to 50 ms, and not for a T _{cathodic-off time} period of 0 to 500 ms flows, - Passing of single or multiple anode current pulses between the cathode and de an anode in the time interval, wherein the current flows for a t _anodic-on period of 0 to 50 ms, and - wherein a duty cycle is in the range of 5 to 100%, and - wherein the cathodic charge (Q _cathodic ) per time interval is always greater than the anodic charge (Q _anodic ) per time interval. A method according to claim 1, characterized in that the single or multiple DC cathode current pulses between the anode and the cathode have a peak current density in the range of 0.01 to 20 A / cm ² . A method according to claim 2, characterized in that the peak current density of the cathode current pulses in the range of 0.1 to 20 A / cm ² , preferably in the range of 1 to 10 A / cm ² . Method according to one of claims 1 to 3, characterized in that the metallic material (a) is a pure metal or an alloy of metals selected from the group consisting of Ag, Au, Cu, Co, Cr, Ni, Fe, Pb , Pd, Pt, Rh, Ru, Sn, V, W, Zn or (b) an alloy consisting of at least one the elements of group (a) and alloying elements selected from the group consisting of C, P, S and Si. Method according to one of claims 1 to 4, characterized in that the T is _{cathodically-to} timeperiod in the range of 1 to 50 ms, the _{T-cathodically from} timeperiod is in the range of 1 to 100 ms, and the T _{at anodisch-} Time period is in the range of 1 to 10 ms. Method according to one of claims 1 to 5, characterized that the duty cycle is preferably in the range of 10 to 95%, and more preferably in the range of 20 to 80%. Method according to one of claims 1 to 6, characterized the deposition rate is preferably at least 0.075 mm / h and more preferably at least 0.1 mm / h. Method according to one of claims 1 to 7, characterized by stirring of the electrolyte at a stirring speed in the range of 1 to 500 ml / min / A. Method according to one of claims 1 to 8, characterized by stirring of the electrolyte by means of pumps, stirrers or ultrasonic excitation. A method according to any one of claims 1 to 9, characterized by a relative movement between the anode and cathode. Method according to claim 10, characterized in that that the speed of relative movement between anode and Cathode up to 600 m / min ranges, preferably in a range of 0.003 to 10 m / min. Method according to claim 10, characterized in that that the relative movement by rotation of the anode and the cathode is achieved relative to each other. A method according to claim 12, characterized by a rotation speed of the rotation of the anode and the cathode relative to each other, which is from 0.003 to 0.15 rpm and preferred from 0.003 to 0.05 rpm. A method according to claim 10 or claim 11, characterized characterized in that the relative movement through a mechanized one Movement generating stroke of the anode and the cathode relative to each other achieved becomes. Method according to claim 10 or 14, characterized that the anode is wound in an absorbent spacer. A method according to any one of claims 1 to 15, characterized in that the electrolyte is a voltage lowering Containing agent or a grain refining agent selected from the group of saccharin, Coumarin, sodium lauryl sulfate and thio-urea. A method according to any one of claims 1 to 16, characterized in that the electrolyte consists of particles additions in the solution contains selected from pure metal powders, metal alloy powders or metal oxide powders of Al, Co, Cu, In, Mg, Ni, Si, Sn, V and Zn, nitrides of Al, B and Si, carbon C as graphite or diamond, carbides of B, Si, Si, W or organic materials such as PTFE and polymer beads, wherein the electrodeposited metallic material is at least 5% of the Particulate additives contains. Method according to claim 17, characterized in that in that the electrolytically deposited metallic material is at least Contains 10% of the particulate additives. Method according to claim 17, characterized in that in that the electrolytically deposited metallic material is at least Contains 20% of the particulate additives. Method according to claim 17, characterized in that in that the electrolytically deposited metallic material is at least Contains 30% of the particulate additives. Method according to claim 17, characterized in that in that the electrolytically deposited metallic material is at least Contains 40% of the particulate additives. A method according to any one of claims 17 to 21, characterized in that the average particle size of Particles existing additives below 10 μm preferably less than 1000 nm, more preferably less than 500 nm, and most preferably below 100 nm. Microcomponent made by electrolytic Pulse current deposition, in particular produced by a method as in any of the claims 1 to 22, which has a maximum dimension of 1 mm, an average grain size equal or less than 1000 nm, where the ratio between the maximum Dimension and the average grain size is greater than 10. Microcomponent according to claim 23, characterized that the ratio between the maximum dimension of the microcomponent and the average grain size greater than 100 is. Microcomponent according to claim 23 or 24 in that it has an equiaxed microstructure.