DE10228323A1 - Patching process for degraded portion of metallic workpiece e.g. pipe and conduit, involves electroplating reinforcing metallic patch to cover degraded portion - Google Patents

Abstract

A reinforcing metallic patch is electroplated to cover the degraded portion without covering the non-degraded portion of metallic workpiece, where the electrodeposited metal of metallic patch has an average grain size of 1000 nm or less. An independent claim is also included for process for in-situ electroforming structural reinforcing layer.

Description

Field of the Invention

The invention relates to a Process for forming coatings of pure metals, metal alloys or metal matrix composites on a workpiece that is electrically conductive or an electrically conductive surface layer contains or forming free-standing layers of nanocrystalline metals, Metal alloys or metal matrix composites through use of pulse electrodeposition. The process uses a drum plating process for the continuous production of nanocrystalline films from pure Metals, metal alloys or metal matrix composites or a selective plating (brush plating) process, the process being pulse electro-deposition and a non-stationary anode or include cathode. New nanocrystalline metal matrix composites are also disclosed. The invention also relates to a Pulse plating process for the manufacture or coating of micro components. The invention also refers to micro components with grain sizes below 1000 nm.

The new procedure can be applied become wear resistant Coatings and foils 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); Carbide from B, Cr, Bi, Si, W; and organic materials such as PTFE and polymer balls. The selective plating process is particularly suitable for in-situ or outdoor applications, such as the repair or preparation of nozzles and molds, turbine blades, Steam generation tubes, reactor core breakthroughs of nuclear power plants and the like. The continuous plating process is particularly suitable for the production of nanocrystalline foils, e.g. For magnetic applications. The process can be based on high-strength, coaxial Microcomponents for use in electronics, biomedicine, telecommunications, applied in the automotive, space and consumer applications become.

Description of the stand the technology / background of the invention

Nanocrystalline materials which are also known as ultra fine grained Materials are referred to, nanophase materials or nanometer-sized materials, what average grain sizes are smaller or equal to 100 nm are shown by a number of known ones Process manufactured including sputtering, laser ablation, Inert gas condensation, high-energy ball milling, sol-gel deposition and electrical deposition. Electro deposit provides the ability a big Number of high density metals and metal alloy compositions with high production rates and low capital investment requirements in a single synthesis step.

The state of the art describes primary 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) a process for the production of nanocrystalline materials, in particular of nanocrystalline nickel. The nanocrystalline material is electrodeposited on a cathode in an aqueous acidic electrolytic cell by applying a pulsed direct current. The cell also optionally contains voltage-reducing agents. The products of the invention include abrasion resistant layers, magnetic materials and catalysts for hydrogen formation.

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

Adler describes in US 4,240,894 (1980) a drum platter for an electrodeposited copper foil 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 electro-formed Cu. The speed of rotation of the drum and the amperage are used to set the desired thickness of the copper foil. The copper foil drawn off from the drum surface is subsequently washed and dried and wound in a suitable spool.

Icxi discloses in US 2,961,395 (1960) a method of electroplating an article without the need to sink the surface being treated into a plating tank. The hand-operated application device serves as an anode and supplies chemical solutions to the metal surface of the workpiece to be plated. The workpiece to be plated serves as the cathode. The hand applicator anode with the braid that contains the electrolyte and the workpiece cathode are connected to a direct current source to produce a metal layer on the workpiece by passing a direct current.

Micromechanical systems (MEMS) are Machines that are constructed from small, moving ones and stationary Parts that have 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. by Photoelectronic training is produced, which is an additional process in which powder is deposited in layers to create the desired structure, e.g. to improve electroless plating by laser. Lithography, electrical training and casting (LIGA) and other photolithography related methods are used to determine aspect ratio (part height to width) to overcome problems in question. Other techniques used include silicon micromachining by mask plating and micro contact printing.

Summary:

It is an object of the invention a reliable and flexible pulse plating process for the formation of coatings of free-standing deposits of nanocrystalline metals, metal alloys or metal matrix composites to offer.

It is another object of the invention Micro components with significantly improved property-dependent reliability and bespoke desired Properties for to provide improved microsystems in overall performance.

Preferred embodiments of the invention are in the respective dependent claims Are defined.

The present invention provides a pulse plating process that consists of a single cathodic on time or multiple cathodic on times of different current densities and single or multiple off times per cycle. Periodic pulse reversal, a bipolar waveform that alternates between cathodic pulses and anodic pulses, can optionally also be used. The cathodic pulses can 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 "reverse pulse" per cycle is always smaller than the cathodic charge (Q _{methodically ka)} the cathodic on times pulses ranging from 0.1 to 50 msec (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 duty 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 circulation 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 until 100%
Frequency: 0 to 1000 Hz
Electrolyte solution temperature: –20 to 85 ° C
Electrolyte solution circulation / agitation rates: ≤ 10 liters per minute per cm ²
Anode or cathode area (0.0001 to 10 l / min. Cm ² )
Workpiece temperature: –20 to 45 ° C
Anode vibration rate: 0 to 350 vibrations / min
Linear speed anode against cathode: 0 to 200 m / min (brush) 0.003 to 0.16 m / min (drum).

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

In the process of the present According to the invention, the electrolyte can preferably be pumped, whisked or Ultrasound excitation with rates from 0 to 750 ml / min / A (ml solution per Minute per passed average amp current) are stirred, preferably at rates from 0 to 500 ml / min / A.

In the process of the present The invention can optionally include a grain refiner or a stress reliever added to the electrolyte be selected from the group of saccharin, coumarin, sodium lauryl sulfate and Thiourea.

This invention provides a method for plating nanocrystalline metal matrix composites a permanent or permanent or a temporary substrate, optionally containing at least 5% by volume of particles consisting of particles, preferably 10% by volume of substances consisting of particles, more preferably 20% by volume consisting of particles of substances, more preferably 30% by volume Particles of existing substances and most preferably 40 vol.% Of particles of existing substances, for applications such as hard outer layers, projectile blunt armor, valve refreshing, valve and turning tool coatings, energy-absorbing armor plates, noise insulation systems, connectors Pipe connections, e.g. used in oil drilling applications, refreshing of roller bearing axles in the railway industry, computer chips, repair of electrical motor and generator parts, repair of grooves in pressure rollers, using tank, drum, rack, selective (e.g. brush plating) and continuous ( eg drum plating) plating processes, which pulse elect Use ro deposit. The substances consisting of particles can 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 balls. The average particle size of the substances consisting of particles is typically below 10 μm, preferably below 1000 nm (1 μm), preferably 500 nm, and more preferably below 100 nm.

The process of this invention optionally offers a process for continuous (drum or belt) plating of nanocrystalline films, which optionally contain solid particles in solution, selected from metal powders, metal alloy powders and metal oxide powders made 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 _Z , and organic materials such as PTFE and polymer balls to impart desired properties including hardness, wear resistance, lubrication, magnetic properties and the like. The drum or tape provides a temporary substrate from which the clad film can be easily and continuously removed.

According to a preferred embodiment of the invention, it is also possible to produce nanocrystalline layers by electroplating without the need to immerse the object to be coated in a coating bath. Brush or tampon plating is a suitable alternative to tank plating, especially when only part of the workpiece is to be plated without the need to mask areas that should not be plated. The brush plating device typically uses a soluble or dimensionally stable anode wrapped in 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. This solution optionally 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 balls to impart desired properties, including hardness, wear resistance, lubrication and the like.

In the case of the drum, tape or Brush plating the relative movement between anode and cathode ranges from 0 to 600 meters per minute, preferably from 0.003 to 10 meters per minute.

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

The microcomponents of the present Invention can preferably a coaxial microstructure over the plated component which are relatively independent of the thickness and structure of the component.

It is another aspect of the present Invention to provide microcomponents in which the average Grain size one Magnitude remains smaller than the outer dimension of the part, thereby maintaining a high level of strength is.

The microcomponents according to this Invention have a significantly improved property-dependent reliability and improved bespoke desired Properties of MEMS structures for their overall performance improved microsystems through preferred coaxial electric deposits, which exclude the fine grain of columnar grain transition in the microcomponent, while reducing the grain size of the deposits below 1000 nm.

Preferred embodiments the invention:

Other features and advantages of this Invention will become more apparent in the following detailed description and examples of preferred embodiments of the invention, along with the attached schematic drawings in which:

1 Figure 3 shows a cross-sectional view of a preferred embodiment of a drum plating device;

2 Figure 3 shows a cross-sectional view of a preferred embodiment of a brush plating device; and

3 a plan view of a mechanized movement device for generating a mechanized stroke of the anode brush.

1 shows schematically a plating tank or container 1 with an electrolyte 2 is filled, which contains the ions of the metallic material to be plated. The cathode is partially immersed in the electrolyte in the form of a rotating drum 3 which is electrical with a power source 4 connected is. The drum is rotated by an electric motor (not shown) via a belt drive and the speed of rotation is variable. The anode 5 can be a plate or conformal anode, as shown, which is electrically connected to the power source 4 connected is. Three different anode arrangements can be used: Compliant anodes as in 1 shown which the contour of the submerged portion of the drum 3 follow, vertical anodes, which are on the walls of the tank 1 positioned and horizontal anodes at the bottom of the tank 1 are positioned. In the case of a film 16 made of metallic material attached to the drum 3 the film is electrodeposited 16 from the drum surface, which consists of the electrolyte 2 surface, drawn, which is covered with the electro-formed metallic material.

2 shows schematically a workpiece to be plated 6 which with 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 to supply the electrolyte solution 2 from a temperature controlled tank (not shown) to the anode braid (absorbing spacer) 10 , The one from the absorbent spacer 10 dripping electrolyte is optional in a bowl 11 collected and returned to the tank. The absorbent spacer 10 which is the electrolyte 2 contains, insulates the anode brush 8th also electrically from the workpiece 6 and sets the distance between the anode 5 and cathode 6 on. The anode brush handle 4 can about the workpiece 6 can be moved manually during the plating process, alternatively the movement can be motorized, as in 3 shown.

3 schematically shows a wheel 12 which is driven by an adjustable speed motor (not shown). A transverse arm 13 can be rotated (axis of rotation A) to the rotating wheel 12 at different positions x on a slot 14 be attached with a liner and an adjusting screw (not shown) to produce a desired stroke or line.

The stroke length can be adjusted by the position x (radius) at which the axis of rotation A of the transverse arm at the slot 14 is attached. In 3 is the transverse arm 13 shown so that it is in a non-stroke, neutral position with the axis of rotation A in the center of the wheel 12 is. The transverse arm 13 has a second pivot axis B, which is defined by a bearing (not shown) sliding in a guideway 15 is appropriate. If the wheel 12 rotates, causes the transverse arm to rotate 13 around axis A at position x the transverse arm 13 , yourself in the guideway 15 move back and forth and pivot about axis B. An anode 5 which have the same features as in 2 is shown is on the transverse arm 13 attached, and moves over the workpiece 6 in a movement that depends on the position x. The movement is usually in the form of the number B. The anode 5 and the workpiece 6 are connected to positive and negative outputs of the current source (not shown), respectively. The kinematic ratio is very similar to that of a steam engine.

This invention relates to the production of nanocrystalline coatings, foils and microsystem components through pulse electro-deposition. Solid particles are optional in the Electrolyte dissolved and are inserted into the deposit.

Nanocrystalline coatings for wear-resistant Applications nowadays are aimed at increasing wear resistance by increasing the hardness and reducing the coefficient of friction by reducing the grain size below 100 nm. It has now been found that the introduction of a sufficient Volume fraction of hard particles the wear resistance of nanocrystalline materials can further improve.

The material properties can also be changed, for example by adding lubricants (such as MoS ₂ and PTFE). In general, the substances consisting of particles can be selected from the group of metal powders, metal alloy powders and metal oxide powders 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 balls.

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 from 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: solid
Anode: solid
Linear speed anode against cathode: not applicable
Average cathodic current density: 0.06A / cm ²
t _on / t _off 2ms / 6ms
Frequency: 125 Hz
Duty cycle: 25%
Deposit time: 1 hour
Deposition rate: 0.09 mm / h
Electrolyte temperature: 60 ° C
Electrolyte circulation rate: vigorous stirring (mechanical bidirectional impeller)

Basic Electrolyte Formulation:
300g / l NiSO ₄ x7H ₂ O
45g / l NiCl ₂ x6H ₂ O
45g / l H ₃ PO ₃
18 g / l H ₃ PO ₄
0.5–3 ml / l interfacially active substance for 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 that 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, which contain 5.9 wt.% P and 45 vol.% B ₄ C, with those of pure coarse-grained Ni, pure nanocrystalline Ni and electrodeposited Ni -P an equivalent chemical composition compared in the attached table. The material hardening is controlled by Hall-Petch grain size reinforcement, while the abrasion wear resistance is optimized at the same time by adding material consisting of B ₄ C particles.

Table: NiP-B ₄ C nanocomposite properties

example

Nanocrystalline Co-based nanocomposites were deposited on Ti and unalloyed steel cathodes immersed in a modified Watts bath for cobalt 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) plate / approx. 6.5 cm ²
Cathode: solid
Anode: solid
Linear speed anode against cathode: not applicable
Peak cathodic current density: 0.100 A / cm ²
Anodic peak current density: 0.300 A / cm ²
Cathodic t _on / t _off / anodic t _on (t _anodic ): 16ms / 0ms / 2ms
Frequency: 55.5 Hz
Cathodic duty cycle: 89%
Anodic duty cycle: 11%
Deposit time: 1 h
Deposition rate: 0.08 mm / h
Electrolyte temperature: 60 ° C
Electrolyte circulation rate: 0.15 liter / min / cm ² cathode area (no pump flow; stirring)

Electrolyte formulation: 300 g / l CoSO ₄ x7H ₂ O
45 g / l CoCl ₂ x6H 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

The hardness and Abrasion properties of a nanocrystalline Co-SiC composite, which Contains 22 vol.% SiC, compared to those of pure coarse-grained Co and pure nanocrystalline Co. Hall-Petch grain size controls a material hardening, while optimized abrasion wear resistance at the same time is caused by the addition of an SiC particle Material.

Table: Co-nanocomposite properties

Continuous plating has been carried out to produce foils, for example using drum plating nanocrystalline foils, which optionally contain solid particles in solution, selected from pure metals or alloys from pure metals or alloys with particle additives, such as metal powder, metal alloy powder and metal oxide powder 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 balls to impart desired properties, including hardness, wear resistance, lubrication, magnetic properties and the like. Nanocrystalline metal foils were deposited on a rotating Ti drum, which was partially immersed in a plating electrolyte. The nanocrystalline film was cathodically electro-formed on the drum using a soluble anode made from a titanium container filled with an anode metal and using a pulse power supply. For alloy foil manufacture, a stream of additional cations of a predetermined concentration was continuously added to the electrolyte solution to establish an equilibrium state concentration of the alloy cations in solution. For metal and alloy foil manufacture, containing matrix composites, a stream of the composite additive was added to the plating bath at a predetermined rate to establish an equilibrium content of the additive. Three different anode arrangements can be used: conformal anodes that follow the contour of the submerged portion of the drum, vertical anodes that are positioned on the walls of the container, and horizontal anodes that are positioned on the bottom of the container. Films were produced at average cathodic current densities, which ranged from 0.01 to 5 A / cm ² and preferably from 0.05 to 0.5 A / cm ² . The speed of rotation 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 plating

Nanocrystalline Co-based nanocomposites were deposited on a rotating Ti drum as described in Example 3, immersed in a modified Watts bath for cobalt. The 15 cm wide nanocrystalline film 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 surface: conformal soluble anode (co-pieces in Ti basket) / not determined
Cathode / cathode area: Ti 600cm ²
Cathode: rotating
Anode: solid
Linear speed anode against 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 _on / t _off / anodic tan (t _anodic ): 1 ms / 1 ms / 0 ms
Frequency: 500 Hz
Cathodic duty cycle: 50%
Anodic duty cycle: 0%
Deposit time: 1 h
Deposition rate: 0.05 mm / h
Electrolyte temperature: 65 ° C
Electrolyte circulation rate: 0.15 liter / min / cm ² cathode area (no pump flow; stirring)

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 average particle diameter
.5 g / l dispersant
pH 1.5

The Co / P-SiC film has a grain size of 12 nm, a hardness from 690 VHN, containing 1.5% P and 22 vol.% SiC.

Example 4

Nanocrystalline nickel-iron alloy foils were deposited on a rotating Ti drum, which was partially immersed in a modified Watts bath for nickel. The nanocrystalline film, 15 cm wide, was electro-cathodically formed on the drum using a soluble anode made from a titanium wire basket filled with Ni round material and a Dynatronics (Dynanet PDPR 50-250-750) pulse power supply. The following conditions were used:
Anode / anode surface: conformal soluble anode (Ni round pieces in a metal cage) / undetermined
Cathode / cathode area: immersed Ti drum / approx. 600 cm ²
Cathode: rotating at 0.018 rpm (or 120 cm / h)
Anode: solid
Linear speed anode against cathode: 120 cm / h
Average cathodic current density: 0.07 A / cm ²
t _on / t _off : 2 ms / 2 ms
Frequency: 250 Hz
Duty cycle: 50%
Manufacturing time: 1 day
Deposition rate: 0.075 mm / h
Electrolyte temperature: 60 ° C
Electrolyte circulation 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 × 4H 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
Rate of admixture: 0.3 l / h
Composition: 23-27% by weight of Fe
Average grain size: 15 nm
Hardness: 750 Vickers

Selective or brush plating is a portable one Method for selectively plating localized areas a workpiece, without immersing the item in a plating tank. There are there are clear differences between selective plating and Tank and barrel plating applications. In the case of selective plating it is difficult 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 the same anode area while of the plating operation, e.g. in the case of flat anodes. In the case of shaped anodes, the anode area cannot be determined exactly, e.g. change in the case of a molded anode and a molded cathode the "effective" anode area too while of the plating process. Selective plating is carried out by Movement of the anode using an absorbent spacer braid is surrounded and contains the electrolyte, back and forth over the Workpiece, which is typically done by an operator until the desired one total area is coated to the required thickness.

Selective plating techniques are especially suitable for the repair and refurbishment of articles, since the brush plating constructions are portable, easy to operate, and no system disassembly which contains the workpiece to be plated. Brush plating also allows plating parts that are too large to be immersed in plating tanks are. Bürstenplattieren is used to provide coatings for improved corrosion resistance, improved wear, improved external appearance (decorative Plating) and it can be used to make worn or mishandled Recover parts. Bürstenplattierungssysteme and plating solutions are commercially available e.g. from Sifco Selective Plating, Cleveland, Ohio, which also mechanized and / or automated tooling for use in production work huge Offers extensive. The plating 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 Made of graphite or Pt coated titanium and they can be medium included to regulate 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 the one you want Maintain temperature range. The absorbent spacer material contains and distributes the electrolyte solution between the anode and the workpiece (cathode), prevents short circuits between Anode and cathode and brushes against the surface the area to be plated. This mechanical rubbing or brushing movement, which on the workpiece while of the plating process affects the quality and that Surface finish of the Coating and allows fast plating rates. Selective plating electrolytes are formulated to provide acceptable coatings over a wide temperature range to produce, which ranges from low, about -20 ° C to 85 ° C. Since the workpiece is often large Comparison to the area which is coated, selective plating is often applied to a workpiece applied at ambient temperature, ranging from low, about –20 ° C to about high 45 ° C. Other than "typical" electroplating operations in the case of selective plating, the temperature of the anode, the Cathode and electrolyte vary significantly. Salting out of Electrolyte components can occur at low temperatures and the electrolyte can be reheated periodically or continuously Need to become, to all precipitated Dissolve chemicals.

A Sifco brush plating 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 produce the "brushing motion", or manually moved back and forth across the workpiece by an operator, or as otherwise indicated. The anode assembly was soaked in the plating solution and the coating was deposited by brushing the plating tool against the cathodically charged work surface, which was composed of various substrates. A peristaltic pump was used to feed the electrolyte into the brush plating tool at predetermined rates. The electrolyte was allowed to drip from the workpiece into a bowl which also served as a "plating 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 transverse arm and the circular motion was adjusted to allow uniform strokes of the anode against the substrate surface. The rotation speed was adjusted to increase or decrease the relative anode / cathode moving speed as well as the anode / substrate contact time at any one location. Brush plating was normally carried out at a rate of approximately 35-175 oscillations per minute, at a rate of 50-85 oscillations per minute 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 copper, 1018 low carbon steel, 4130 high carbon steel, 304 stainless steel, a 2.5 inch outer diameter steel tube, and a weld-covered I625 tube. The cathode size was 8 cm ² with the exception of 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 plating power supply (Dynanet PDPR 20-30-100) was used.

Standard substrate cleaning provided by Sifco and activation processes were used.

Example 5:

Nanocrystalline pure nickel was stored on an 8 cm ² surface electrode with a 35 cm ² anode, using the described structure. Usually the workpiece has a much larger area than the anode. In this example, a workpiece (cathode) was chosen to be significantly smaller than the anode to ensure that the oversized anode, although kept in motion, always covered the entire workpiece to enable the cathode current density to be determined. Since a non-consumable anode was used, NiCO _{3 was} periodically added to the plating bath to maintain the desired Ni ²⁺ concentration. The following conditions were used:
Anode / anode area: graphite / 35 cm ²
Cathode / cathode area: unalloyed steel / 8 cm ²
Cathode: stationary
Anode: mechanically automated, oscillating at 50 vibrations per minute
Linear speed anode against cathode: 125 cm / min
Average cathodic current density: 0.2 A / cm ²
t _on / t _off 8 ms / 2 ms
Frequency: 100 Hz
Duty cycle: 80%
Deposit time: 1 h
Deposition rate: 0.125 mm / h
Electrolyte temperature: 60 ° C
Electrolyte circulation rate: 10 ml of solution per minute per cm ^{2 of} anode area or 220 ml of solution per minute per ampere of average current passed
Electrolyte Formulation:
300 g / l NiSO ₄ x7H ₂ O
45 g / l NiCl ₂ x6H 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 construction described under the following conditions:
Anode / anode area: graphite / 35 cm ²
Cathode / cathode area: unalloyed steel / 8 cm ²
Cathode: stationary
Anode: mechanically automated, oscillating at 50 vibrations per minute
Linear speed anode against cathode: 125 cm / min
Average cathodic current density: 0.10 A / cm ²
t _on / t _off : 2 ms / 6 ms
Frequency: 125 Hz
Duty cycle: 25%
Deposit time: 1 h
Deposition rate: 0.05 mm / h
Electrolyte temperature: 65 ° C
Electrolyte circulation rate: 10 ml of solution per minute per cm ^{2 of} anode area or 440 ml of solution per minute per ampere 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 structure previously described. A 1.5 inch wide tape was plated on the outer diameter of a 2.5 inch 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 outer diameter steel tube made of 2101 A1 carbon steel / undefined
Cathode: rotating at 12 rpm
Anode: stationary
Linear speed anode against cathode: 20 cm / min
Average cathodic current density: indefinite
Total current let through: 3.5 A.
t _on / t _off : 2 ms / 6 ms
Frequency: 125 Hz
Duty cycle: 25%
Deposit time: 1 h
Deposition rate: 0.05 mm / h
Electrolyte temperature: 55 ° C
Electrolyte circulation rate: 0.44 l solution per minute per ampere passed
Electrolyte Formulation:
260 g / l NiSO ₄ x7HzO
45 g / l NiCl ₂ x6H ₂ O
7.8 g / l FeCl ₂ x4H ₂ O
45 g / l H ₃ BO ₃
30 g / l Na ₃ C ₆ H ₅ O ₇ .2H _Z 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 approximately 4.5 cm long, 0.5 cm wide and had an average depth of approximately 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 plated on the defect area until its original thickness was restored.
Anode / anode area: graphite / 35 cm ²
Cathode / cathode area: I625 / undetermined
Cathode: stationary
Anode: mechanically automated, oscillating at 50 vibrations per minute
Linear speed anode against cathode: 125 cm / min
Average cathodic current density: indefinite
t _on / t _off : 2 ms / 6 ms
Frequency: 125 Hz
Duty cycle: 25%
Deposit time: 2 h
Deposition rate: 0.087 mm / h
Electrolyte temperature: 55 ° C
Electrolyte circulation rate: 0.441 solution per minute per ampere passed average current
Electrolyte Formulation:
300 g / l NiSO ₄ x7H ₂ O
45 g / l NiC1 ₂ x6H 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, which have dimensions or dimensions over everything of less than 1000 μm (1 mm), are becoming increasingly important for use in electronic, biomedical, telecommunications, automotive, space and consumer applications. Metallic macro system components with a maximum dimension over everything from 1 cm to over 1 m, which contain materials of conventional grain size (1–1000 μm), show a ratio between maximum dimension and grain size ranges from 10 to 10 ⁶ . This number reflects the number of grains over the maximum part dimension. If the maximum size of the component is reduced to less than 1 mm using conventional grain size material, the component can potentially be made from only a few grains, or a single grain, and the relationship between the maximum dimension of the microcomponent and the grain size ranges becomes apparent 1. In other words, a single or only a few grains extend along the entire part, which is not desirable. In order to increase the component reliability of microcomponents, the ratio between the maximum component dimension and grain size ranges must be increased to over 10 by using a smaller-grain material, since this material class typically shows grain size values 10 to 10,000 times smaller than those of conventional materials.

For conventional LIGA and other clad microcomponents begin electrical deposition initially with a fine grain size on the Substrate material. With increasing deposit thickness in the growth direction becomes ordinary the transition to columnar grains observed. The thickness of the columnar Grains are enough typically from a few to a few tens of micrometers during their Length some Can reach hundreds of micrometers. The consequence of such Structures is the development of anisotropic properties with increasing deposit thickness, and reaching a critical Thickness at which only a few grains cover the entire cross section cover the components, with widths below 5 to 10 μm. Another drop leads in the thickness of a component to a bamboo structure, which leads to a significant loss leads to firmness. So the microstructure of electrodeposited microcomponents, which are currently in use, totally inadequate in terms of property requirements both about the width and the thickness of the component based on the grain size and average grain size.

Until now, parts were made of Materials more conventional Grain size, which were known to have serious reliability problems mechanical properties such as the Young module, deformation resistance, Limit tensile strength, fatigue strength and suffering from creep behavior, known to be extremely sensitive on processing parameters that are related to the construction of these components are connected. Many of the problems that occurred were caused by inadequate scaling of key microstructure features (i.e. grain size, grain shape, Grain orientation) with the external size of the component, resulting in unusual Property variations led which are usually the same for macroscopic components Material were not observed.

Example 9:

Metal micro spring fingers are used to IC chips with a high number and density of pads contact, and to transport energy and signals to and from the chips. The springs offer high-value electrical contacts for a variety interconnect structures, including chip-scaled semiconductor packages, high-density intermediate switch connectors and sensor contacts. The massive enable parallel interlayer structures and assemblies High speed testing of separate integrated circuit components, the on a compliant support are fixed, and allow test electronics in close proximity to the to be localized to be tested integrated circuit components.

The micro spring fingers require high form strength and flexibility. A 25 μm thick layer of nanocrystalline Ni was plated on 500 μm long gold-coated CrMo fingers using of the following conditions:
Anode / anode area: Ni / 4.5 × 10 ^-3 cm ²
Cathode / cathode area: gold-plated CrMo / approximately 1 cm ²
Cathode: stationary
Anode: stationary
Linear speed anode against cathode: 0 cm / min
Average cathodic current density: 50 mA / cm ²
t _on / t _off : 10 ms / 20 ms
Frequency: 33 Hz
Duty cycle: 33%
Deposit time: 120 minutes
Deposition rate: 0.05 mm / h
Electrolyte temperature: 60 ° C
Electrolyte circulation rate: none
Electrolyte Formulation:
300 g / l NiSO ₄ x7H ₂ O
45 g / l NiCl ₂ x6H 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 nanofingers clearly showed one higher Contact force compared to fingers "more conventional Grain size ".

Claims (26)

A method of cathodically depositing a selected metallic material on a permanent or temporary substrate in nanocrystalline form with an average grain size of less than 100 nm, using pulse electrodeposition, with a deposition rate of at least 0.05 mm / h, comprising: providing an aqueous Electrolyte containing ions of the metallic material, maintaining the electrolyte at a temperature in the range between 0 to 85 ° C, providing an anode and a cathode in contact with the electrolyte, passing single or multiple DC cathode current pulses between the anode and cathode with a cathode current Pulse frequency in the range of approximately 0 to 1000 Hz, at pulsed intervals during which the current flows for a T _on time period in the range of approximately 0.1 to 50 ms and for a T _{off time} period in the range of approximately 0 to 500 ms does not flow, and passing single or multiple DC-A Node current pulses between the cathode and the anode at intervals during which the current flows for a T _{anodic time} period in the range from 0 to 50 ms, with a duty cycle in the range from 5 to 100% and one cathodic charge (Q _cathodic ) per interval is always larger than an anodic charge (Q _anodic ). 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 about 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 about 0.1 to 20 A / cm ² , preferably in the range of about 1 to 10 A / cm ² . Method according to one of claims 1 to 3, characterized in that that the selected metallic material (a) is a pure metal selected from the group consisting of Ag, Au, Cu, Co, Cr, Ni, Fe, Pb, Pd, Rt, Rh, Ru, Sn, V, W, Zn or (b) an alloy consisting of at least one of 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 _{on time} period is in the range of about 1 to about 50 ms, the T _{off time} period is in the range of about 1 to 100 ms and the T _{anodic time} period in Range is from about 1 to 10 ms. Method according to one of claims 1 to 5, characterized in that the working cycle before is in the range of 10 to 95%, and more preferably is in the range of 20 to 80%. Method according to one of claims 1 to 6, characterized in that that the cathode current pulse frequency ranges from 10 Hz to 350 Hz. Method according to one of claims 1 to 7, characterized in that that the deposition rate is preferably at least 0.075 mm / h and more preferred is at least 0.1 mm / h. Method according to one of claims 1 to 8, characterized by stirring of the electrolyte at a stirring rate in the range from 0 to 750 ml / min / A, preferably in the range from 0 to 500 ml / min / A. A method according to claim 9, characterized by stirring the Electrolytes using pumps, agitators or ultrasonic excitation. Method according to any one of claims 1 to 10, characterized by a relative movement between the anode and cathode. A method according to claim 11, characterized in that the Speed of the relative movement between anode and cathode ranges from 0 to 600 m / min, preferably from 0.003 to 10 m / min. A method according to claim 11, characterized in that the relative movement by rotating the anode and the cathode relatively to each other is achieved. A method according to claim 13, characterized by a rotational speed the rotation of the anode and the cathode relative to each other, which ranges from 0.003 to 0.15 rpm and preferably from 0.003 to 0.05 rpm. Method according to claim 11 or claim 12, characterized in that that the relative movement through a mechanized movement Generating stroke of the anode and the cathode achieved relative to each other becomes. A method according to claim 11 or 15, characterized in that the anode is wrapped in an absorbent spacer. Method according to any one of claims 1 to 16, characterized in that that the electrolyte is a stress reliever or a grain refiner contains selected from the group of saccharin, coumarin, sodium lauryl sulfate and Thiourea. Method according to any one of claims 1 to 17, characterized in that that the electrolyte contains additives consisting of particles in solution, selected from pure metal powders, Metal alloy powders or metal oxide powders from Al, Co, Cu, In, Ng, Ni, Si, Sn, V and Zn, nitrides of Al, B and Si, carbon C (Graphite or diamond), carbides of B, Bi, Si, W or organic Materials such as PTFE and polymer balls, the electrodeposited metallic material contains at least 5% of the additives consisting of particles. A method according to claim 18, characterized in that the Electrodeposited metallic material made up of at least 10% Particles existing additives contains. A method according to claim 18, characterized in that the Electrodeposited metallic material made up of at least 20% Particles existing additives contains. A method according to claim 18, characterized in that the Electrodeposited metallic material made up of at least 30% Particles existing additives contains. A method according to claim 18, characterized in that the Electrodeposited metallic material made up of at least 40% Particles existing additives contains. Method according to any one of claims 18 to 22, characterized in that that the average particle size is that of particles additions less than 10 μm is preferably below 1000 nm, more preferably below 500 nm, and am most preferred below 100 nm. Microcomponent manufactured by a pulse electrodeposition process, in particular produced by a pulse electrodeposition process as in any of the claims 1 to 22, which has a maximum dimension of 1 mm, equal to an average grain size or less than 1,000 nm, the ratio between the maximum Dimension and the average grain size is greater than 10. Microcomponent according to claim 24, characterized in that The relationship between the maximum dimension of the microcomponent and the average grain size greater than 100 is. Microcomponent according to Claim 24 or 25, characterized in that that it has a coaxial microstructure.