EP1213372B1 - Process and arrangement for the galvanic deposition of nickel, cobalt, nickel alloys or cobalt alloys with periodic current pulses and use of the process - Google Patents

Abstract

A method for galvanically depositing nickel, cobalt, nickel alloys or cobalt alloys in a galvanic bath includes using electrolytes containing nickel compounds or cobalt compounds. At least one anode and at least one cathode of the bath are subject to periodic current pulses. The IA/IC ratio of the anode current density IA to the cathode current density IC is selected to be greater than 1 and smaller than 1.5, where the anode current density IA and the cathode current density IC are defined as current densities with respect to a deposition body on which deposition occurs during the application of periodic current pulses where the deposition body serves as anode and cathode respectively. The charge ratio QA/QC=TAIA/TCIC of the charge QA, transported during anode pulse of duration TA, to the charge QC transported during a cathode pulse of duration TC, is between 30% and 45%. A bath for carrying out the method may have contoured anodes, current restrictors, a cleaning device for the electrolyte, and a circulating device with recycling of the electrolyte through nozzles.

Description

The present invention relates to a process for the electrodeposition of nickel, cobalt, nickel alloys or cobalt alloys in a galvanic bath using a nickel compounds or cobalt compounds such as electrolytes containing sulfates or sulfamates or chlorides. Such electrolytes for electrodeposition are for example made DE 25 58 423 . DE 22 18 967 . US 2,470,775 such as EP 0 835 335 known. For deposition, at least one anode and at least one cathode of the bath is subjected to periodic current pulses. Such methods with the aid of current pulses are known from the prior art, for example, from the already mentioned publications US 2,470,775 such as EP 0 835 335 known. From the US-A-3,915,835 For example, there is known a method of electroplating ElNi-Sil coatings using a contoured cathode.

In principle, such processes can be used to deposit nickel, cobalt, nickel alloys or cobalt alloys in a galvanic bath. A particular problem, however, arises when the components to be produced by such a deposition, certain mechanical properties such as a given strength or a given ductility (ductility) should have. Such a problem arises in particular when the component to be produced is to be connected later inextricably with other components, for example, to be welded. For this purpose, certain minimum requirements are generally given to the extensibility, so that a welded joint between a galvanically produced nickel or cobalt layer or a layer of a nickel or cobalt alloy and other components with sufficient strength and durability of the welded joint can be realized. However, if too high extensibility of the corresponding, to be welded Achieved layer, so reduces the strength of the corresponding layer, so that the corresponding layer may no longer meet the specified requirements for mechanical strength. This is especially true for components that are to be exposed to relatively high loads, as may occur, for example, in components in rocket engines. Specifically, these are the thrust chambers of rocket engines, which consist essentially of the components injection head, combustion chamber and exhaust nozzle.

It has been found that the methods known from the prior art can not guarantee the necessary properties of the electrodeposited nickel or cobalt layers or layers of nickel or cobalt alloy, which are indissoluble for such a layer with other components, such as an alloy based on iron or nickel, in particular for welding, are an indispensable prerequisite.

The object of the present invention is therefore to provide a method for the electrodeposition of nickel, cobalt, nickel alloys or cobalt alloys in a galvanic bath, in which at least one anode and at least one cathode of the bath is subjected to periodic current pulses and with the nickel or cobalt layers or layers of a nickel or cobalt alloy can be produced, which can be permanently connected to other components, in particular can be welded to other components.

This object is achieved by the features of claims 1 and 16.

In the method according to the invention for the electrodeposition of nickel, cobalt, nickel alloys or cobalt alloys in a galvanic bath, an electrolyte is used which contains corresponding nickel compounds or cobalt compounds, in particular sulfates or sulfamates or chlorides. For deposition, at least one anode and at least a periodic current pulses are applied to a cathode of the bath, ie a so-called pulse plating process is used. As a cathode normally acts a deposition body on which a layer of the corresponding material to be deposited. According to the invention, it is now provided that the ratio I _A / I _C of anode current density I _A to cathode current density Ic is selected to be greater than 1 and smaller than 1.5 and the charge ratio Q _A / Q _c = (T _A × I _A ) / (T _C · I _C) is transported during an anode pulse of the duration T _a to the charge Q _a transported during a cathode pulse of the duration T _C charge Q _C between 30% and 45%.

It has been found that it is only with such a choice of conditions that the necessary for a permanent connection of the deposited layer with other components properties can be achieved just in terms of strength and ductility of the layer. In the prior art according to the EP 0 835 335 On the other hand, it is proposed in particular to choose a ratio I _A / I _C which is at least 1.5. Suitable parameter ranges for obtaining a layer with the aforementioned properties are not discussed in this document. Also on a suitable choice of the ratio Q _A / Q _C nothing is said there.

In particular, it may be provided that the ratio I _A / I _{C is} between 1.2 and 1.45, in particular between 1.3 and 1.4, and the charge ratio Q _A / Q _C - (T _A * I _A ) / (T _C · I _C ) is between 35% and 40%. For these parameter ranges, particularly advantageous properties of the deposited layer can be determined, in particular with regard to the strength and the extensibility.

In order to achieve an improved and more uniform deposition of the layer on a deposition body, which ultimately also benefits the loading of the layer over its entire extent, it can be provided that at least one contoured anode is used for the deposition, the contour of which is aligned with the contour of the deposition body on which the nickel, the cobalt, the nickel government or the cobalt alloy is deposited is. By means of this adaptation of the anode contour, it is possible in particular to achieve a constant distance between the anode and the deposition body over almost the entire contour of the deposition body, which permits a more uniform deposition.

In the case where several anodes are provided in the bath, a contoured anode is used for at least one of the anodes located closest to the deposition body. For the anodes closest to the deposition body, the effect of contouring the anode is more pronounced than for more remote anodes, i. that anodes without contouring can be used for these more remote anodes, which may be more cost-effective and can be used independently of the specific shape of the deposition body. Thus, by means of this suitable combination of contoured and non-contoured anodes, an optimum with regard to the quality of the deposition as well as the effort required for this purpose can be achieved.

For example, to form the contoured anode, a contoured container permeable to the ions of the nickel or cobalt to be deposited or the nickel alloy or cobalt alloy and filled with bodies of nickel, cobalt or a nickel alloy or cobalt alloy may be used. Special containers for such bodies are basically made DE 25 58 423 in the form of titanium or plastic baskets which are filled there with nickel pellets, but there is no contouring of the container is provided.

As an alternative to such containers, however, a solid electrode body which has at least one coating of the nickel, cobalt or the nickel alloy or cobalt alloy to be deposited or, in principle, consists of solid nickel, cobalt or a solid nickel alloy or cobalt alloy can also be used as the contoured anode.

It may be necessary during the deposition process that a targeted influencing of the deposition is necessary, which should be different for different areas of the deposition body. This influencing can take place additionally or else alternatively to the aforementioned measure of the contoured anodes. For this purpose it can be provided that the deposition body is at least partially shielded by current shutters during a part of the entire deposition period. In the shielded areas, a reduced deposition is then achieved as compared to the unshielded areas during the time these areas are shielded. As a result, local influencing of layer properties, in particular the layer thickness, but possibly also the mechanical layer properties, can be realized on the deposition body.

In particular, the current shutters can be arranged in those regions of the deposition body in which a preferred deposition takes place. Thus, an excessive layer growth in these areas can be prevented in comparison to other areas and thus a more homogeneous layer growth can be realized over the entire deposition body.

It may preferably be provided a removal of interfering foreign elements or other suspended suspended particles from the bath to obtain a pure electrolyte solution as possible. For this purpose, at least before the beginning of the deposition, a cleaning of the electrolyte with the aid of activated carbon and / or hydrogen peroxide take place. In particular, 0.5 g / l to 5 g / l, in particular 1 g / l to 3 g / l of activated carbon can be used to purify the electrolyte and 0.5 ml / l to 3 ml / l, in particular 1 ml / l before the deposition to 2ml / l of 30% hydrogen peroxide.

However, in order not only to guarantee the purest possible electrolyte solution at the beginning of the process by such a purification, but also to maintain this purity as far as possible throughout the entire process, one can Purification of the electrolyte take place alternatively or additionally during the deposition. In a preferred development of the invention, filtering of the electrolyte, for example by means of activated carbon filters, is provided for this purpose during the deposition on the one hand, and on the other hand foreign elements are removed from the electrolyte by a selective bath. Such a selective bath corresponds to a galvanic bath, in which a targeted separation of foreign elements and thus their removal from the electrolyte takes place by targeted control of the currents. The thus purified electrolyte then ideally contains only the desired elements, in the case of a nickel electrolyte then ideally only nickel or nickel alloys in the compounds mentioned above, in the case of a cobalt electrolyte ideally only cobalt or cobalt alloys in the compounds mentioned above , The purified electrolyte is then returned to the galvanic bath.

It can also be carried out a circulation of the electrolyte, wherein the electrolyte is circulated through at least one circulating pump and a return of the electrolyte takes place in the bath by means of nozzles. The nozzles can now in particular be designed and arranged in the bath such that a circulation of the bath is favored by the nozzles and / or a flow of the electrolyte directed onto the deposition body is achieved. In this case, the nozzles not only fulfill the purpose of circulation and return of the electrolyte in the bath, but by this optimized type of recycling, the deposition process in the bath favors, as always optimal mixing or targeted supply of a pure electrolyte as possible to the deposition body is guaranteed.

The inventive method is basically suitable for the production of different components that are later inextricably linked to other components, for example, to be welded. However, the method is particularly suitable for the production of components that are exposed to high loads. This applies, for example, to components for rocket engines, in which case in particular the application of the method for the production of injection heads and / or combustion chambers and / or thrusters for rocket engines is called. However, the method can also be used for other components that are subject to high loads in later operation, and therefore must have sufficient strength, but nevertheless should have sufficient extensibility, such as supporting mechanical structures, components for kilns or similar arrangements with high thermal stress, etc. By varying the parameters of the method according to the invention, the achievable strength as well as the extensibility of the deposited layer over a relatively wide range is adjustable, as will be explained in more detail below.

• mindestens eine konturierte Anode, deren Kontur an die Kontur eines Abscheidungskörpers angepasst ist,
• eine Einrichtung zur Ansteuerung der Anode und der Kathode des Bades mit periodischen Strompulsen,
• Stromblenden zur zumindest teilweisen Abschirmung des Abscheidungskörpers,
• eine Filtereinrichtung zur Filterung des Elektrolyten und
• eine Umwälzeinrichtung zur Umwälzung des Elektrolyten, aufweisend mindestens eine Umwälzpumpe und Düsen zur Rückführung des Elektrolyten in das Bad.

Another object of the invention is a special galvanic bath for the electrodeposition of nickel or nickel alloys or cobalt or cobalt alloys with an electrolyte, comprising

• at least one contoured anode whose contour is adapted to the contour of a deposition body,
• a device for controlling the anode and the cathode of the bath with periodic current pulses,
• Current shields for at least partial shielding of the deposition body,
• a filter device for filtering the electrolyte and
• a circulation device for circulating the electrolyte, comprising at least one circulating pump and nozzles for returning the electrolyte into the bath.

This special galvanic bath can be used to implement a specific development of the aforementioned method. The aforementioned method can in principle but also in otherwise trained galvanic Baths are realized, which are suitably adapted to the basic inventive method or one of its developments.

The further embodiment of this special bath can be done by a corresponding adaptation to the features of the above description concerning the inventive method. For example, it can be provided that the at least one contoured anode is formed as a contoured container which can be filled with bodies of nickel or cobalt or a nickel alloy or a cobalt alloy.

As already stated, it can be provided, in particular, that a plurality of anodes are arranged in the bath, wherein only the anodes closest to the deposition body are formed as contoured anodes. This means that, of course, the other anodes also have a certain contour, but in this case, only the contour of those anodes which are closest to the deposition body should be adapted to the contour of the deposition body. The contouring can only be done in one spatial direction e.g. in the longitudinal direction of the anode, or it can also take place in more than one spatial direction, e.g. additionally perpendicular to the longitudinal direction.

Furthermore, the cleaning device may include a filter device, in particular an activated carbon filter, and a Selektivbad. As a result, both suspended in the electrolyte suspended particles as well as unwanted foreign elements can be removed from the electrolyte.

A specific embodiment of the present invention will be described below with reference to FIGS FIGS. 1 to 3 described.

Fig. 1:

Abhängigkeit der Festigkeit und Dehnbarkeit der abgeschiedenen Schicht von dem Ladungsverhältnis Q_A/Q_C im erfindungsgemäßen Bereich des Stromdichtenverhältnisses I_A/I_C

Fig. 2:

Aufbau eines erfindungsgemäßen Bades

Fig. 3:

Draufsicht auf eine spezielle Ausgestaltung eines erfindungsgemäßen Bades.

Show it:

Fig. 1:

Dependence of the strength and extensibility of the deposited layer on the charge ratio Q _A / Q _C in the range of the current density ratio I _A / I _C according to the invention

Fig. 2:

Structure of a bath according to the invention

3:

Top view of a special embodiment of a bath according to the invention.

For the inventive method, a galvanic bath with an electrolyte is provided in the context of the following example, which contains nickel compounds. In principle, however, a galvanic bath with cobalt compounds is conceivable. For this purpose, according to the known from the prior art electrolytes as nickel compounds or cobalt compounds, for example, nickel sulfate and nickel chloride or nickel sulfamate and nickel chloride can be provided, and in the case of cobalt compounds, the corresponding sulfates, sulfamates or chlorides. For the specific possibilities of the composition of the electrolyte, reference is made to the cited prior art. There may also be provided additional additives in the electrolyte, such as that in US Pat EP 0 835 335 or DE 22 18 967 quoted sulfonated naphthalene or the in US 2,470,775 Column 3, paragraph 2.

The method of so-called pulse plating is now used for the deposition, that is, the charging of the anodes and cathodes of the bath with periodic current pulses, which is known in principle from the cited prior art. There are wide parameter ranges called from which the specific settings for the process, in particular for the choice of current densities and pulse durations can be selected. It has However, it has been found that with such parameter values, weldability of the electrodeposited layer can not be achieved since the layers thus deposited do not have the necessary strength and ductility requirements.

These necessary strengths can only be achieved if the ratio I _A / I _C of anode current density I _A to cathode current density I _C greater than 1 and less than 1.5 is selected and the charge ratio C _A / Q _C = (T _A · I _A ) / (T _C · I _C) of the transported during an anode pulse of the duration T _a charge Q _a to the transported during a cathode pulse of the duration T _C charge Q _C between 30% and 45%, with better results are obtained when the Ratio I _A / I _{C is} between 1.2 and 1.45 and the best results are achieved for a ratio between 1.3 and 1.4, the charge ratio Q _A / Q _C = (T _A * I _A ) / (T _C · I _C ) is in each case between 35% and 40%. It has therefore been found that no arbitrary choice of the ratios I _A / I _C and Q _A / Q _C may be made in order to achieve the desired advantageous properties of the deposited layer, but that this only for a certain value range of the ratio I _A / I _C and a value range coupled thereto for the ratio Q _A / Q _{C is} given. This is fulfilled in particular for the aforementioned value ranges.

Reference is made to Fig. 1 , which determines the dependence of the yield strength (0,2-proof stress) R _{p 0,2} . the strength R _m and the extensibility A _{5 of} a deposited according to the aforementioned process winding layer of the charge ratio Q _A / Q _C for current density ratios I _A / I _C between 1.3 and 1.4 describes. It can be seen here that with a charge ratio of between 35% and 40%, the strengths and the extensibility are within a medium range, ie an optimum balance is found between the extensibility and the strength of the deposited layer. If the charge ratio is increased, the extensibility increases, but at the same time the strength decreases more and more, so that there is no sufficient mechanical stability of the deposited layer. If, on the other hand, the charge ratio is further reduced, the strength increases, however the extensibility decreases markedly, which means that the deposited layer becomes very brittle and there is a risk of material fractures, especially in the area of welds in which material shrinkage and therefore thermo-mechanical stressing of the layer occur during welding. Even if the current density ratio is increased or decreased, the values become correspondingly less favorable. For cobalt and cobalt alloys, an analogous behavior is expected.

Fig. 2 shows schematically the construction of the bath for the realization of the invention, which is filled with an electrolyte as described above. In this case, there is a deposition body 2 such as a combustion chamber of a rocket engine in a bath 1. On this deposition body is now a coating, for example, nickel galvanically generated. For this purpose, at least one anode 3 is embedded in the bath 1, wherein the anode 3 is contoured such that it is adapted to the contour of the deposition body 2. The contouring can be given only in one spatial direction, for example in the longitudinal direction of the anode 3, or it can also be provided in more than one spatial direction, for example additionally perpendicular to the longitudinal direction. In Fig. 2 For reasons of simplicity, only a single anode 3 is shown. Fig. 3 on the other hand shows a possible arrangement of several anodes 3a, 3b in a bath 1, wherein those anodes 3a, which are closest to the deposition body, are formed as contoured anodes, since there makes the positive influence of the contouring most noticeable. By contrast, the more remote anodes 3b can be designed as universally usable, in the simplest case flat anodes, for which any standardized anode form can be used. Consequently, only the anode 3 a closest to the deposition body 2 may need to be adapted to the specific shape of different deposition bodies 2. This anode concept represents an optimization of the effect of the anodes 3a, 3b while maintaining a possible universal arrangement.

The contoured anode 3 in Fig. 2 is formed by a contoured container 8, which is formed for example as a titanium basket and therefore permeable is for the necessary for the deposition of nickel ions. The container 8 may also be surrounded by additional, likewise permeable to the nickel ions sheaths such as from a bag. The nickel is introduced here in the form of small nickel bodies 9 in the container 8 and can be easily replenished in a simple manner with a gradual consumption of nickel during the deposition process. A device 4 activates the anode 3 and the deposition body 2 acting as a cathode in the bath 1 with periodic current pulses for carrying out the described pulse plating process.

There are further provided current apertures 5, which shield certain areas of the deposition body 2 at least during part of the deposition process. In the case after Fig. 2 the edges of the deposition body 2 are shielded, since in these areas without shielding an increased deposition of the nickel would take place and so an inhomogeneous deposition would take place over the entire deposition body 2. Here, the current apertures 5 should be provided as rings, which are arranged concentrically around the edge regions of the deposition body 2. By means of the current diaphragms 5, these regions can be shielded, at least over a certain time, so that a more homogeneous deposition over the entire deposition body 2 can be achieved over the entire deposition period. In another form of the deposition body 2 can be shielded analogously, the corresponding areas in which an increased deposition takes place, such as surveys. Thus, an otherwise lower deposition in other areas such as wells can be compensated. The current sheds 5 can for example be arranged displaceably or even completely removable in the bath 1, for which purpose suitable devices are to be provided.

Before the deposition, it makes sense to carry out a cleaning of the electrolyte. This can in particular with the aid of activated carbon in a concentration of preferably 1 g / l to 3 g / l and with 30% hydrogen peroxide in a concentration of preferably 1 ml / l to 2 ml / l carried out, with higher or lower concentrations are in principle possible.

A cleaning device 6 is used to clean the electrolyte of interfering foreign elements and suspended particles during the deposition process and takes place with the aid of activated carbon filters 10 and a selective bath 11, in Fig. 2 only shown schematically. The discharge and return of the electrolyte in the bath is carried out by appropriate supply and discharge lines. As a result, a particularly high purity of the electrolyte and its almost complete liberation from foreign elements, in particular foreign metals, as well as suspended particles can be achieved. It can be reduced by this part of the method, in particular the proportion of foreign elements Fe, Cu, Cr, Al, Zn, Co in the nickel bath to values below 0.1 mg / l, which additionally benefits the properties of the deposited layer, as such a reduction in the proportion of foreign elements further improves the extensibility of the deposited layer and, in addition, guarantees a further high or even higher strength of the deposited layer.

The bathroom also has a in Fig. 2 schematically shown circulating device 13 for circulating the electrolyte, which consists of a circulation pump 12 and suitably designed and suitably arranged nozzles 7 for recycling the electrolyte. Especially the return to the bath in this form by means of nozzles 7 can additionally be used to favor a circulation of the electrolyte in the bath 1 and on the other hand to supply the electrolyte specifically to the deposition body 2. The appropriate arrangement and orientation of the nozzles 7 should be chosen so that these specifications are met. In principle, the cleaning device 6 and the circulation device 13 could also be combined in a single device, for example by recycling the electrolyte purified in the cleaning device 6 into the bath 1 with the aid of nozzles 7.

Claims (19)

1. Process for the electrodeposition of nickel, cobalt, nickel alloys or cobalt alloys in an electrolytic bath (1) using an electrolyte which contains nickel compounds or cobalt compounds, wherein periodic current pulses are applied to at least one anode (3, 3a, 3b) and at least one cathode of the bath (1) for the deposition of nickel, cobalt, nickel alloys or cobalt alloys on a deposition body (2), wherein the deposition body (2) acts as anode or as cathode,
   characterized
   in that the ratio I_A/I_C of anode current density I_A to cathode current density I_C is selected to be greater than 1 and less than 1.5, and the charge ratio Q_A/Q_C=(T_A·I_A)/(T_C·I_C) of the charge Q_A transported during an anode pulse of the duration T_A to the charge Q_C transported during a cathode pulse of the duration T_C is between 30% and 45%, wherein the anode current density I_A and the cathode current density I_C are defined as current densities during the anodic or cathodic phases of the current pulses on the deposition body (2).
2. Process according to Claim 1,
   characterized
   in that the ratio I_A/I_C is between 1.2 and 1.45, in particular between 1.3 and 1.4, and the charge ratio Q_A/Q_C=(T_A·I_A)/(T_C·I_C) is between 35% and 40%.
3. Process according to either of Claims 1 and 2,
   characterized
   in that the deposition is carried out using at least one contoured anode (3, 3a, 3b), the contour of which is matched to the contour of the deposition body (2), on which the nickel or the cobalt or the nickel alloy or the cobalt alloy is to be deposited.
4. Process according to Claim 3,
   characterized
   in that a plurality of anodes (3, 3a, 3b) are provided in the bath (1), and a contoured anode (3a) is used at least for one of the anodes (3a), which is arranged closest to the deposition body (2).
5. Process according to either of Claims 3 and 4,
   characterized
   in that the contoured anode (3a) is formed using a contoured container (8), which is permeable to the nickel or the cobalt or the nickel alloy or the cobalt alloy to be deposited and is filled with bodies (9) of nickel or cobalt or of a nickel alloy or cobalt alloy.
6. Process according to either of Claims 3 and 4,
   characterized
   in that the contoured anode (3, 3a, 3b) used is a solid electrode body having at least a coating of the nickel or cobalt to be deposited or of the nickel alloy or cobalt alloy to be deposited.
7. Process according to one of Claims 1 to 6,
   characterized
   in that the deposition body (2) is partially shielded at least during part of the overall deposition duration by current diaphragms (5).
8. Process according to Claim 7,
   characterized
   in that the current diaphragms (5) are arranged in those regions of the deposition body (2) in which preferred deposition takes place.
9. Process according to one of Claims 1 to 8,
   characterized
   in that the electrolyte is cleaned before the start of the deposition and/or during the deposition.
10. Process according to Claim 9,
    characterized
    in that the electrolyte is cleaned before the start of the deposition using 0.5 g/l to 5 g/l, in particular 1 g/l to 3 g/l, of activated carbon and using 0.5 ml/l to 3 ml/l, in particular 1 ml/l to 2 ml/l, of 30% strength hydrogen peroxide.
11. Process according to either of Claims 9 and 10,
    characterized
    in that the electrolyte is cleaned during the deposition by filtering the electrolyte, in particular with the aid of at least one activated carbon filter (10), and by removing foreign elements from the electrolyte with the aid of at least one selective bath (11).
12. Process according to one of Claims 1 to 11,
    characterized
    in that, at least during part of the deposition duration, the electrolyte is circulated with the aid of at least one circulating device (13), and the electrolyte is returned into the bath (1) by means of nozzles (7).
13. Process according to Claim 12,
    characterized
    in that the nozzles (7) are formed and arranged in the bath (1) in such a manner as to achieve circulation of the bath (1) and/or an electrolyte flow directed at the deposition body (2).
14. Use of a process according to one of Claims 1 to 13 for producing components for rocket engines.
15. Use of a process according to one of Claims 1 to 13 for producing injection heads and/or combustion chambers and/or propelling nozzles for rocket engines.
16. Electrolytic bath (1) for the electrodeposition of nickel or nickel alloys or cobalt or cobalt alloys, having

    - an electrolyte, which contains nickel compounds or cobalt compounds, on a deposition body (2) having at least one contoured anode (3, 3a, 3b), the contour of which is matched to the contour of the deposition body (2),

    - a device (4) for activating the anode (3, 3a, 3b) and a cathode (2) of the bath (1) with periodic current pulses having a ratio I_A/I_C of greater than 1 and less than 1.5 and a charge ratio Q_A/Q_C=(T_A·I_A)/(T_C·I_C) of between 30% and 45%,

    - current diaphragms (5) for at least partially shielding the deposition body (2),

    - a cleaning device (6) for cleaning the electrolyte, and

    - a circulating device (13) for circulating the electrolyte, having at least one circulating pump (12) and nozzles (7) for returning the electrolyte into the bath,

    wherein the anode current density I_A and the cathode current density I_C are defined as current densities during the anodic or cathodic phases of the current pulses on the deposition body (2).
17. Electrolytic bath according to Claim 16,
    characterized
    in that the at least one contoured anode (3, 3a, 3b) is in the form of a contoured container (8), which can be filled with bodies (9) of nickel or cobalt or of a nickel alloy or of a cobalt alloy.
18. Electrolytic bath according to either of Claims 16 and 17,
    characterized
    in that a plurality of anodes (3, 3a, 3b) are arranged in the bath (1), wherein only those anodes (3a) located closest to the deposition body (2) are in the form of contoured anodes.
19. Electrolytic bath according to one of Claims 16 to 18,
    characterized
    in that the cleaning device (6) contains a filter device (10) and a selective bath (11).

Images