ES2624761T3 - Procedure for the preparation of polycrystalline structures that have improved mechanical and physical properties - Google Patents

Abstract

A method of preparing an article, the process comprising the steps of: a) electrodeposition of a metallic material comprising copper from an aqueous electrolyte comprising copper pyrophosphate using direct current (DC) metallization, pulse current (PP) ) and / or reverse pulse metallization (PR) using an average current density that varies from 5 to 10 000 mA / cm2, a direct pulse service time that varies from 0.1 to 500 ms, a standby time that ranges from 0 to 10 000 ms, a service time per inverse pulse ranging from 0 to 500 ms, a maximum direct current density that varies from 5 to 10 000 mA / cm2, a maximum inverse current density 10 which varies from 5 to 20,000 mA / cm2, a frequency that varies from 0 to 1000 Hz and a duty cycle that varies from 5 to 100%, to form or at least partially metallize an article, the metallic material i) having a size of medium grain between 4 nm and 5 μm, and ii ) an impurity content of less than 20 ppm by weight of S, less than 50 ppm by weight of O, less than 50 ppm by weight of P and less than 300 ppm by weight of C; and b) heat treatment of the electrodeposited metal material at a temperature between 0.25Tm and 0.7Tm K 20 for a period of time between 1 second and 75 hours to induce grain growth in the metal material such that at least one portion of metallic material shows an increase of at least 0.3 of the fraction of the special grain limit and an intensity value of the crystallographic texture of less than 7.5 times the random.

Description

Procedure for the preparation of polycrystalline structures that have improved mechanical and physical properties 5

CROSS REFERENCE TO RELATED APPLICATIONS

In accordance with U.S. 35. §119 (e), this application claims the benefit of the provisional US request. UU. No. 61/014,448 filed December 18, 2007.

10 FIELD

This specification refers to production processes of polycrystalline materials that have improved mechanical and physical properties. This specification also refers to the limit engineering of

15 grain, electrodeposition and heat treatment.

INTRODUCTION

The following paragraphs are not an admission that something analyzed in them is from the prior art or part of the knowledge of those skilled in the art.

Intergranular degradation procedures (for example, fatigue, creep and corrosion) can be the main causes of failure in the premature and unpredictable service of normally ductile engineering materials. Intergranular degradation procedures occur at grain boundaries and can lead to failure.

25 of a component by propagation through the intercrystalline network. Therefore, intergranular degradation procedures can be governed by the specific structure of the grain limit, the chemistry of the grain limit (i.e., the segregation and precipitation of solute), and the size and shape of the grain (i.e., connectivity)

Grain boundaries crystallographically described by low ratios es (i.e. 29) of the network of sites

Coincidence (CSL) may have more orderly structures, may be less prone to solute interaction, and may show resistance and sometimes even immunity against intergranular corrosion, intergranular slippage, cavitation and fracture (see G. Palumbo and KT Aust, in Materials Interfaces: Atomic Level Structure and Properties, eds. D. Wolf, and S. Yip, Chapman and Hall, New York (1992) 190-211). A grain limit is called "special" if its interfacial crystallography is within an acceptable range  of , in which 29, and

35  <15 -1/2 as defined by Brandon, Acta Metall., 34, 1479 (1966).

Recent advances in imagery microscopy by automated crystallographic orientation (IOM) have made it possible to easily determine the distributions of these low "special" grain limits  (29) in conventional polycrystalline materials. This may allow the optimization of material processing techniques to

In order to increase the general population of low  grain limits to effect microstructures resistant to intergranular degradation, and the stochastic evaluation of the intrinsic reliability of the resulting components and structures.

US Patent No. 5,702,543 to Palumbo describes the thermomechanical processing of materials

45 metallic, namely, in the manufacture of components from a face-centered cubic alloy, in which the alloy is cold worked and recoated, the cold work is carried out in a series of separate stages, being followed each stage by an annealing stage. The resulting product has a grain size not exceeding 30 microns, a fraction of "special" grain limit of not less than 60% and all the main intensities of crystallographic texture are less than twice those of random values. The product has a

50 enhanced resistance to intergranular degradation and corrosion by stress cracking, and has highly isotropic volumetric properties.

U.S. Patent No. 6,129,795 to Lehockey et al. describes a metallurgical procedure for the improvement of the microstructure of precipitation-reinforced superalloys based on nickel and iron used in 55 high temperature applications by increasing the frequency of the "special" low CSL grain limits to levels greater than a fifty %. Processing involves the application of precipitation-specific thermomechanical processing sequences to hardenable alloys that comprise a series of stages of deformation and cold-recrystallization-annealing performed within specific limits of deformation, temperature and annealing time. The materials produced by this procedure show an improved resistance to

60 high temperature degradation (eg creep, hot corrosion, etc.), increased weldability and fatigue resistance of high cycles.

U.S. Patent No. 6,344,097 to Limoges et al. discloses a surface treatment procedure to improve intergranular corrosion and resistance to intergranular cracking of components manufactured from alloys based on austenitic Ni-Fe-Cr comprising the application of cold surface work to

a depth in the range of 0.01 to 0.5 mm, for example, by high blasting intensity, followed by recrystallization heat treatment preferably at solution temperatures (> 900 ° C). The cold and annealing surface work procedure can be repeated to further optimize the microstructure of the region near the surface. After the final heat treatment, the process can optionally comprise the application of cold surface work of reduced intensity, producing a cold worked depth of 0.005 to 0.01 mm, in order to further improve the resistance to cracking by providing to the region near the residual compression surface.

U.S. Patent No. 6,132,887D2 of Clouser et al. discloses the electrodeposition of copper sheets having an average grain size in the range of 0.5 to 3 microns. The acid electrolyte solution is formed by dissolving a copper feed material, for example, copper shot, copper wire or recycled copper, in a sulfuric acid solution. Phosphates are considered to represent undesirable electrolyte impurities. After electrodeposition, the sheet is counted at temperatures in the range of 120 ° C to 400 ° C.

SUMMARY

In one aspect of this specification, a method of preparing an article having improved properties according to claim 1 comprises the steps of: electrodeposition of a metallic material to form or at least partially metallize an article, the metallic material having a average grain size between 4 nm and 5 μm and an impurity content of less than 20 ppm by weight of S, less than 50 ppm by weight of O, less than 50 ppm by weight of P and less than 300 ppm by weight of C ; and heat treatment of the electrodeposited metallic material at a temperature between approximately 0.25Tm and 0.7TmK for a period of time sufficient to induce the growth of the grain in the metallic material such that at least a part of the metallic material exhibits an increase in at least 0.3 in the fraction of the special grain limit and an intensity value of the crystallographic texture of less than 7.5 times the random.

In another aspect of this specification, a method of preparing an article having improved properties according to claim 1 comprises the steps of: electrodeposition of a metallic material comprising Cu to form or at least partially metallize an article, having the metallic material an average grain size between 4 nm and 5 μm and an impurity content of less than 20 ppm by weight of S, less than 50 ppm by weight of O, less than 50 ppm by weight of P, and less than 300 ppm by weight of C; and heat treatment of the electrodeposited metallic material at a temperature between approximately 0.25 Tm and 0.7 Tm K for a period of time sufficient to induce the growth of the grain in the metallic material such that at least a part of the metallic material has an increase of at least 0.3 in the fraction of the special grain limit and an intensity of crystallographic texture of less than 7.5 times the random.

In yet another aspect of the present specification, an article may be provided comprising a substantially pure electrodeposed and heat treated fine grained metallic material having a crystallographic texture intensity value of less than 7.5 times the random and a content of special grain limit of at least 50%.

These and other characteristics of the applicant's teachings are set forth in this document.

DRAWINGS

The person skilled in the art will understand that the drawings, described below, are for illustration purposes only. The drawings are not intended to limit the scope of the applicant's teachings in any way.

Figure 1 is a microscopic orientation microscopy (IOM) photomicrograph after electrodeposition, according to example 2 described herein.

Figure 2 is a photomicrograph of orientation microscopy (IOM) of an electrodeposited copper microstructure after heat treatment of grain growth, in accordance with example 2 described herein.

Figure 3 is a figure of copper orientation microscopy (IOM) poles 8 weeks after electrodeposition, according to example 2 described herein.

Figure 4 is a figure of orientation microscopy (IOM) microscopy poles of an electrodeposited copper microstructure after heat grain growth treatment, according to example 2 described herein.

Figure 5 is a graphical comparison of the content of the "special" grain limit (fsp) of electrodeposited copper after thermal treatments of grain growth at 150 ° C, 300 ° C and 500 ° C for varying periods, according to the Example 3 described herein.

Figure 6 is a graphic comparison of the intensity values of electrodeposited copper texture after heat treatment of grain growth at 150 ° C, 300 ° C and 500 ° C for varying periods, according to example 3 described in the Present descriptive report.

5 Figure 7A is a graphical comparison of the laminar strength of pulverized films using a commercial Cu target (upper part) together with pulverized films using two problem Cu spray targets prepared by the applicant (target "A" in the middle and target "B" at the bottom), according to example 5 described herein.

10 Figure 7B is a scanning electron microscopy photomicrograph of a commercial Cu target after spraying (upper part) together with SEM photomicrographs of the surfaces of the two problem Cu spray targets prepared by the applicant after equivalent spray service (target "A" in the middle and target "B" at the bottom), according to example 5 described in the

15 present specification.

Figure 7C is a surface surface profilometer scan of a commercial Cu target after the spray service (upper part) along with surface profilometer sweeps of the surfaces of two problem Cu spray targets prepared by the applicant. after spraying service

20 equivalent (target "A" in the middle and target "B" at the bottom), according to example 5 described herein.

Figure 8 is a transmission electron microscope (TEM) photomicrograph of nickel after electrodeposition, according to example 6 (not according to the invention) described herein.

25 descriptive.

Figure 9 is an orientation microscopy (IOM) photomicrograph of an electrodeposited nickel microstructure after thermal grain growth treatment, according to example 6 (not according to the invention) described herein. .

Figure 10 is a figure of image microscopy by orientation (IOM) poles of an electrodeposited nickel microstructure after heat grain growth treatment, according to example 6 (not according to the invention) described in the Present descriptive report.

35 DESCRIPTION OF VARIOUS MODES OF EMBODIMENT

Various apparatus or procedures will be described below to provide an example of an embodiment of each claimed invention. No embodiment described below limits any claimed invention and any claimed invention may cover devices or procedures that are not

40 described below. The claimed inventions are not limited to devices or procedures that have all the characteristics of any one of the devices or procedures described below or to the characteristics common to multiple or all of the devices described below. One or more inventions may reside in a combination or sub-combination of the elements of the apparatus or procedural steps described below or in other parts of this document. It is possible that an apparatus or procedure described to

The following is not an embodiment of any claimed invention. The applicant (s), inventor (s) and / or owner (s) reserve all rights over any invention disclosed in an apparatus or procedure described below that is not claimed in this document and does not abandon, renounce or target the public any of said inventions by their disclosure in this document.

50 The applicant's teachings refer to the application of a deliberately controlled grain growth heat treatment of electrodeposited metal materials sufficiently pure of relatively fine grain to increase the fraction of the "special" grain limit (fsp) by at least 30% (0.3) against the material after metallization and to create a crystallographically randomized polycrystalline microstructure. Polycrystalline materials prepared according to the applicant's teachings may possess enhanced resistance.

55 to intergranular degradation and show improved mechanical and physical isotropy.

The desired increase in the "special" grain limit fraction can be expressed mathematically as fsp, 2 - f sp, 1> 0.3, where fsp, 2 is the "special" grain limit fraction after the heat treatment of grain growth and fsp, 1 is the fraction of the "special" grain limit of the precursor material before heat treatment of

60 grain growth. In some examples, the desired increase (or  fsp) of the "special" grain limit fraction may be more than 0.4. The heat treatment can obtain metallic materials that have a total special grain limit content of at least 50%, and in some cases more than 70%. In addition, the heat treatment can obtain metallic materials that have a maximum intensity of the crystallographic texture of less than 7.5 times the random and preferably less than five times the random.

The deliberate formation of polycrystalline microstructures rich in "special" grain boundaries through procedures based on conventional thermomechanical processing has been based on the knowledge that selective recrystallization induced at the most highly defective grain boundary sites in the microstructure of a deformed polycrystalline metallic metallic material results in a high probability of continuous substitution of high energy disordered grain boundaries with those that have a higher atomic order close to that of the crystalline network itself. The applicant's teachings refer to the creation of randomly oriented polycrystalline materials that show enhanced mechanical and physical properties by virtue of their possession of a high fraction of "special" low CSL interfaces resistant to degradation  (29) between constituent crystals of the materials. The inventors have realized that microstructural optimization can be achieved by heat treatment of sufficiently pure fine-grained polycrystalline precursor metal materials without the application of deformation.

The substitution of disordered “general” grain boundaries of high energy (> 29) with “special” low energy grain limits (29) that have an atomic order close to that of the crystalline network itself may be accompanied by a decrease in the preferential crystallographic orientation of the material. The term "randomized crystallographic texture" is defined herein as a polycrystalline microstructure in which a single crystallographic orientation is not observed at a frequency greater than 7.5 times (and preferably 5 times) its appearance in a sample with a distribution completely random crystals. This is expressed as a texture intensity value (TI) and therefore a completely random agglomeration of crystals would show an IT value of the unit, while a crystallographically randomized sample for the purposes of this disclosure would show an IT <7, 5 and preferably <5. Crystallographically randomized materials are substantially isotropic.

Randomized crystallographic texture and high fsp can be achieved by controlled grain growth through the heat treatment of a polycrystalline precursor material of initially fine grain (5 μm grain size). The relatively small grain size of the precursor material provides an important driving force for grain growth to appear during heat treatment.

The precursor for heat treatment is copper or an alloy that initially has a microstructure of fine grain, and may consist substantially of a cubic structured material. Fine grain in this context is defined as having an average grain size ranging from approximately 4 nm to 5 μm, a grain size range that is below the typical grain size range of commonly used engineering alloys. .

It has been unexpectedly found that fine-grained materials produced by electrodeposition (including electroplating or electroforming) can be very suitable as precursors because grain growth can be induced without having to subject the materials to plastic deformation and primary recrystallization before grain growth. Recrystallization and grain growth are two basically different phenomena to the extent that grain growth is defined as the consumption of smaller crystals by energy-preferred larger crystals, while the term "recrystallization" is defined as the organization of the

dislocations in low energy configurations (intergranular "cell" walls or "subgran" boundaries) that

Over time they form different grain boundaries by themselves.

Fine-grained polycrystalline metals and alloys have a strong thermodynamic potential for microstructural transformation through grain growth. At the same time, there is also a strong thermodynamic potential for the segregation of the elements of impurities codeposited in the grain boundaries. This segregation can decrease the grain limit energy and effectively destroy the energy difference between the "special" and "general" limits. Therefore, it is preferable that the precursor material is sufficiently free of impurities that could result in the harmful segregation of solute, an undesirable second phase precipitation, grain limit setting effects and / or other material embrittlement mechanisms during the grain growth stage of the processing. For some examples, the specific impurity elements and the corresponding concentration levels expressed in weight at those considered to be harmful are 20 ppm of S, 50 ppm of P,  50 ppm of O and 300 ppm of C.

The manufacture of high purity polycrystalline solids that show average grain size values below 5 μm can be difficult to achieve by traditional metallurgical means, which typically produce grain sizes in the range of 30 to 500 μm. This is because most of the traditional metallurgical processing techniques work at or near equilibrium, where the formation of coarse grains of more than 5 μm in diameter is preferred from the energy point of view. To form fine-grained structures not in equilibrium, synthesis techniques can be based on mechanisms that involve undesirable chemical contamination of the matrix material. An example of this phenomenon is the use of organic and / or inorganic grain refiners in electroplating. These electrolyte additives help in the formation of highly unbalanced fine-grained or amorphous structures, but invariably co-position together with the metal being reduced, resulting in excessively high concentrations of elements of harmful impurities, for example but not limited a, S, O, C, N, H, and P. Electrodeposition (including electroplating or electroforming) can be used to create the

precursor material if the reduction of the desired metal is carried out in such a way that it is not accompanied by an excessive amount of undesirable impurities.

According to various embodiments of the applicant's teachings, the formation of the fine grain microstructure can take place as a result of some other structural refining mechanism that predominates in an electrolyte that is sufficiently free of constituents that contain impurities. An example is the electrodeposition of relatively high purity fine-grained copper from pyrophosphate-based electrolytes. By selecting the chemical constituents of the solution and the parameters of the metallization process, pure fine-grained copper can be electrodeposited with a very low concentration of the impurity elements of interest, as presented in Table 1 below, in which the results of the chemical test of a sample of high purity copper of typical fine grain from the pyrophosphate electrolyte are compared with the reference results of electrodeposited copper from the widely used acid sulfate bath which

contains polyethylene glycol and copper of purity of “high conductivity free of oxygen” (OFHC) prepared

pyrometallurgically conventional.

Table 1. Properties of high purity fine grain electrodeposited Cu, fine grain electrodeposited Cu

Conventional purity and Cu reference material of “high oxygen-free conductivity” prepared

pyrometallurgically conventional.

Material Description

Processing path Grain size (microns) [S] ppm [C] ppm [O] ppm [N] ppm [H] ppm [P] ppm

Cu piro.

Electrodeposition 0.2 8.8 121 <50 <50 3 <50

Cu sulfate acid + PEG

Electrodeposition 0.8 15.6 404 330 <50 Four. Five <50

OFHC Cu Reference

Wash > 20 14.8 100 <50 <50 <50 <50

In this case, grain refinement in the "fine" regime has been achieved without chemical contamination exceeding that specified by the precursor material purity requirement described above. Therefore, one aspect of the applicant's teachings is the selection of a precursor material production technique that achieves the required level of grain refinement without any dependence on processing constituents that contain harmful impurities to do so.

Ultimately, the exact concentration at which these elements become harmful depends on both the chemistry of the matrix and the embrittlement capacity of the impurity element. For example, sulfur can be a powerful embrittlement agent in nickel-based alloys, and should be maintained at levels below about 100 ppm, and preferably below 20 ppm. In the case of copper, it is known that mechanical and physical properties are sensitive to oxygen concentration, hence the widespread use of OFHC copper ("high oxygen-free conductivity"), which typically specifies an oxygen content of less 50 ppm, in industrial applications where copper is subjected to heating. Although the applicant does not wish to be bound by the theory, it is believed that, since grain boundaries have a tendency to segregate or "sweep" impurities during grain growth, each and every one of the mechanisms of fixation and fragilization of the limit of grain that are activated during the heat treatment stage of the processing should be minimized.

Although the chemical composition of the precursor material is a factor with respect to the avoidance of the effects of embrittlement of the grain limit after heat treatment of grain growth, it should be understood that the scope of the applicant's teachings is not limited in any way by the concentration of those elements that do not result in fixation or embrittlement of the grain limit of the precursor material after the heat treatment of grain growth. In other words, sufficiently pure metals and alloys of two or more elements are equally suitable for application as a precursor material for the metallurgical processing methodology disclosed herein.

The temperature and / or the time interval of the grain growth heat treatment can be selected to ensure that the expected microstructural evolution takes place without excessive grain growth, that is, for example, so that the average grain size of the material After heat treatment do not exceed 50 μm.

The grain growth heat treatment is a conventional metallurgical heat treatment carried out in a controlled manner within the range of 0.25 to 0.7 Tm K, the homologous melting temperature of the metal or alloy in question, during a period of sufficient time to induce at least a threefold increase in the grain size of the material, generally between 1 second and 75 hours. It should be appreciated that if a material

Polycrystalline with a starting grain size of d grows so that each grain limit has migrated a distance of a grain diameter, then the grain size of this material will be 3d. Therefore, the minimum dimensional change that a grain will experience if all its grain limits migrate a grain diameter is an increase of three times.

The heat treatment under optimal conditions of temperature and time results in a microstructure with an improved preferential crystallographic orientation and the "special" grain limit content approximates the optimum conditions. In the case of crystallographic orientation, the optimal condition is defined as a totally random texture defined as a texture intensity value once random (TI = 1). In the case of the special grain limit content, the highest fsp obtainable is 100% (fsp = 100%). The temperature and time conditions of the grain growth heat treatment according to the applicant's teachings are selected to maximize fsp and / or minimize texture intensity.

Fine grain precursor materials are produced through electrodeposition using an aqueous electrolyte. The electrolytic deposition of the precursor material is carried out using direct current (DC) metallization, current pulses (PP) and / or reverse pulse metallization (PR), the electrodeposition parameters being an average current density that varies from 5 at 10 000 mA / cm2, a direct working time that varies from 0.1 to 500 ms, a rest time that varies from 0 to 10 000 ms, an inverse working time that varies from 0 to 500 ms, a density of maximum direct current that varies from 5 to 10 000 mA / cm 2, a maximum inverse current density that varies from 5 to 20 000 mA / cm2, a frequency that varies from 0 to 1000 Hz and a duty cycle that varies from 5 to 100% (see Erb's teachings in U.S. Patent Nos. 5,352,266 (1994) and 5,433,797 (1995) and Palumbo in U.S. Patent Publication No. 20050205425.

Electrodeposition as discussed herein may include electroforming for the preparation of integral components comprising a bulk metal material, as well as electroplating for cases where the metallic material is deposited as a coating on a substrate. However, it should be understood that the applicant's teachings should not be limited by the precursor material formation technique and that, in principle, any formation procedure that is suitable for the production of non-deformed metals and alloys of fine-grained. Apart from the electrodeposition techniques described herein, it should be appreciated that the precursor material can be formed from a variety of synthesis techniques including, for example but not limited to, electrolytic deposition, deposition without electric current, gas condensation. inert (IGC), physical vapor deposition (PVD), chemical vapor deposition (CVD), pulsed laser deposition and sol-gel processing.

It is preferred that the surfaces of the fine grain precursor material do not set the desired grain growth and thus impede the development of the desired microstructure. For this to be the case, the minimum thickness of acceptable material may be related to its average grain size and, as described above, an increase of three times the diameter is the minimum dimensional change that a grain undergoes if all its limits of grain will migrate a distance of at least one grain diameter. This defines the increase in the average minimum allowable grain size that may be necessary to achieve generalized substitution of "general" grain limits with "special" grain limits, as desired. It is conceivable that the free surfaces of a material begin to prevent the growth of grain once the grain size reaches one tenth of the thickness of the layer of material and is therefore preferable, in some examples, that the thickness of The material layer exceeds (3 × 10) d = 30d in which d represents the initial average grain size of the precursor material.

The teachings of the applicant are especially suitable for the manufacture of articles whose performance is influenced in some way by deformation or degradation mechanisms mediated by the grain limit such as ductility due to high degree of deformation, intergranular corrosion, corrosion by intergranular tensofisuration, creep, fatigue of high cycles, embrittlement due to precipitation and fracture caused by fissures whose propagation is dependent on the presence of active intergranular pathways.

In some particular examples, metal articles produced in accordance with the applicant's teaching can be used as shaped load liners. In general terms, electroformed metals or alloys may not meet the demands of use as shaped charge coatings, since they are subject to contamination of impurities that results in a embrittlement of harmful material and proportionally to a poor performance of the component in the service. These impurities can often be inherent in the process and originate from electroplating bath additives used to achieve gloss of the deposit, grain refinement, leveling / smoothness, chelating effects, removal of hydrogen gas bubbles, and so on. It has now been found that the heat treatment of deliberate controlled grain growth of highly pure electrodeposed copper of fine grain results in improved ductility at a high degree of deformation compared to conventional materials.

The applicant's teachings are also particularly suitable for the manufacture of articles whose performance is influenced in some way by the preferred crystallographic orientation. In some particular examples, metal articles produced in accordance with the applicant's teaching can be used as spray targets. Generally speaking, electroformed metals or alloys may not satisfy

sufficiently the demands of use as spray targets, since they are: fine-grained but unsuitable for use as spray targets because they result in unacceptable chemical contamination of the sprayed film; or of high purity, but highly textured or of excessively coarse grain and therefore unsuitable for use as spray targets because its performance with respect to the quality of the

5 sprayed film, spray uniformity and overall target life is diminished. It has now been found that deliberately controlled heat treatment of highly pure fine-grained electrodeposited spray targets results in a spray uniformity, a global target life time, a uniformity of the quality of the sprayed film and a uniformity of sheet resistance of the powdered film improved.

10 Articles according to the applicant's teaching can find use in a variety of applications that require enhanced mechanical isotropy and resistance to degradation mechanisms mediated by the grain limit. Specific areas of application include high-power, creep-resistant and fatigue-resistant power cord, improved intergranular tensile corrosion of nickel alloys in ambient environments.

15 high temperature steam nuclear generator, other high temperature heat exchangers in the petrochemical industry and high temperature creep resistant materials in gas turbine applications.

It should be appreciated that, apart from the manufacture of articles that show microstructural improvements over the entire volume of the microstructure of the component, the teachings in this document can be directed to the preparation of articles that employ a near-surface treatment (for example , at a depth of between 5.08 μm and 2.54 mm (0.0002 and 0.1 inches)) for the creation of functionally graduated materials in which the outer "skin" and the internal volume show different microstructural characteristics ( for example, fraction of special grain limits). In some examples, a metallic, ceramic or polymer component may at least partially metallize with a metal or alloy that possesses a fine-grained microstructure. After metallizing, part or all of the component may be exposed to a heat treatment of grain growth at a temperature and time sufficient to induce a desirable increase in the fraction of special grain boundaries in at least a portion of the near region. of the surface of the component, thereby providing improved physical or mechanical properties to the region near the surface of the component. In addition, surface specific heat treatment techniques, such as induction heating, may be suitable for heating the surface of a component to enhance the fraction of the special grain limit and / or the intensity of the surface texture outside the metallic material without significantly affecting the microstructure of its core. Other specific heat treatment techniques that can be used to achieve grain growth in the near-surface layer or selected portions of the metallized article include only local heating by a light source, that is, by a laser treatment. In this way, the microstructure

The interior of the metallized component can remain substantially unaffected by heat treatment, while the near-surface region experiences controlled grain growth as described in accordance with the applicant's teachings.

In summary, this descriptive report discloses procedures for the preparation of copper materials

40 polycrystallines showing reduced mechanical and physical anisotropy and resistance to enhanced intergranular mediated degradation, this improved performance being attributable to factors that include an optimized microstructure showing the following characteristics:

 an increase in the fraction of "special" grain limits of at least 0.3, with a limit fraction of 45 total "special" global grain in some examples of between 50 and 100%; Y

 a crystallographic texture intensity value of less than 7.5 times the random, and preferably less than 5 times the random.

50 To effect the formation of a material that shows these characteristics, the general procedure according to the applicant's teachings may include, as a first stage, the deposition of a copper material for use as a precursor. By control of the processing conditions used to form the precursor, the precursor material can show the following general characteristics:

55  an average grain size between 4 nm and 5 μm;

 sufficient purity to avoid the embrittlement of the grain limit during the heat treatment of grain growth (for example, less than 20 ppm by weight of S, less than 50 ppm by weight of each impurity element selected from the group consisting of P and O, and less than 300 ppm by weight of C); Y

60  a layer thickness of metallic material equal to or greater than about 30 times the initial average grain size of the metallic precursor material.

The general procedure according to the applicant's teachings may include, as a second stage, the heat treatment of the precursor material at a temperature between 0.25 and 0.7 Tm K for a time sufficient to

induce at least a threefold increase in the grain size of the material. By controlling the temperature and the duration of the heat treatment, the microstructure of the metallic material can develop a greater desirable fraction of special grain boundaries and a more randomized crystallographic texture.

Reference is now made to the following examples, which are intended to be illustrative but not limiting.

EXAMPLE 1 (not according to the invention)

External Purity Window

2.3 mm thick independent metallized electroformed fine-grained copper precursor material on a polished Ti cathode (150 cm2) in a conventional acidic copper sulfate bath (60 I tank) containing molecular weight polyethylene glycol 6,000 as a grain refiner and using phosphor copper as the anode material. The metallization current was supplied by a Dynanet ™ PDPR 40-100-400 pulse power supply (Dynatronix, Amery, Wisconsin, USA). The electrolyte and electroplating conditions used, together with chemical analysis data of the resulting electrodeposited material, are shown in Table 2. A PHILIPS XL-30 ™ FEGSEM microscope was used in electronic backscatter mode and equipped with TSL version 5.0 software of orientation microscopy (IOM) to characterize copper and the results are indicated in table 3 below. The average grain size after deposition of electroformed copper was determined to be in the range of 800 to 900 nm. Individual samples were then subjected to heat treatments by immersion in molten salt at 350 ° C (0.46Tm K) for 60, 180, and 600 seconds, respectively. It was observed that the average grain size of this material remained relatively small (~ 1.7 μm), even after heat treatment at 350 ° C (0.46Tm K). In addition, the fraction of "special" grain limits increased from 62% in the condition after deposition to a maximum of only 69% after heat treatment, which is accompanied by an imperceptible change in the preferred crystallographic orientation. Other attempts were then made to achieve grain growth by heat treatment at temperatures higher than 400 ° C (0.50Tm K) and 450 ° C (0.53Tm K) and the results are also contained in Table 3. These Heat treatments produced similar results to heat treatment tests at 350 ° C (0.46Tm K). In other words, no significant change in grain size, texture intensity or percentage of "special" grain limits was observed. The microstructural evolution of electrodeposited copper from the acid sulfate bath may, therefore, have been prevented by the presence of impurity elements that set the grain boundaries originated by the co-refined polyethylene glycol grain refiner. This contamination may have hindered the growth of grain in general, and the development of the desired randomized texture and the distribution of the grain limit character rich in "special" grain boundaries, as indicated in the column of  may have been avoided. fsp of table 3, which illustrates the total increase of fsp of the heat treated material versus the non heat treated material.

Table 2. Bath chemistry and metallization conditions used for electroforming a Cu metallization of fine grain together with the results of the chemical analysis carried out in the metallized

Bath chemistry

CuSO4150 g / l H2SO4190 g / l Ion chloride 40 mg / l PEG MW6000 3 g / l

Metallization conditions

Electrolyte temperature: 24 ° C pH: 1 Electrolyte stirring speed (normalized for the cathode area): 47 ml / (min.cm Average current density (Imed) [mA / cm2]: 150 Maximum current density [mA / cm2]: 300 Working time [ms]: 20 Standby time [ms]: 20 Reverse pulse working time [ms]: 0 Maximum current density of the inverse pulse [mA / cm2]: 0 Metallization time [ h]: 16

2)

Chemical analysis of materials

Element

concentration by weight (ppm)

S

<20

P

<50

OR

510

C

400

Table 3. Results of the IOM analysis of samples cut from a fine grain electroformed Cu metallized and heat treated under varying temperature and time conditions.

Heat treatment after metallization (° C)

Heat treatment time (seconds) Grain size (μm) Intensity Texture Total special (%  29) fsp

Ambient temperature (0.22 Tm K)

n / a 0.9 1.7 62 0

350 (0.46 Tm K)

60 1.7 1.7 68 0.06

350 (0.46 Tm K)

180 1.7 2.1 67 0.05

350 (0.46 Tm K)

600 1.7 2.1 69 0.07

400 (0.50 Tm K)

60 1.7 2.0 69 0.07

450 (0.53 Tm K)

60 1.7 1.7 68 0.06

EXAMPLE 2

An independent 0.5 mm thick metallized of fine-grained copper precursor material was electroformed on a polished Ti cathode (150 cm2) in a bath based on copper pyrophosphate (60 l tank) using OFHC copper as anode material. The metallization current was supplied by a Dynanet ™ PDPR 40-100-400 pulse power supply (Dynatronix, Amery, Wisconsin, USA). The electrolyte and electroplating conditions used are indicated in Table 4. The results of the chemical test of this electrodeposited precursor material are also contained in Table 4. The evolution of the distribution of the grain limit character, grain size and orientation Preferred crystallographic data were evaluated using the same orientation microscopy (IOM) procedure described above and the results are indicated in Table 5 below. Figure 1 is an IOM photomicrograph illustrating the microstructure of pure copper immediately after electrodeposition. The average grain size after deposition of the electroformed copper was determined to be in the range of 200 to 400 nm. The ratio of thickness to grain size was determined to be in the range of 1250 to 2500. Immediately after metallization, two copper metallized samples were cut and one of these samples was immersed for 2 minutes in a molten salt bath heated to 300 ° C (0.42 Tm K). An IOM photomicrograph of this thermally treated microstructure is indicated in the figure

2. The second cut sample of copper metallization was heat treated. Due to the fact that this fine-grained copper sample in the condition after deposition was relatively free of the impurity elements that set the grain limit S, P, O and C, grain growth took place at room temperature and He was allowed to proceed without obstacles for a period of 8 weeks after electroforming. It can be seen that the use of a controlled deliberate grain growth heat treatment at a relatively high temperature (300 ° C = 0.42 Tm (K)) for a short period of time (2 minutes) resulted in a sustained substitution more efficient of "general" higher energy grain limits by "special" grain limits that have a higher atomic order close to that of the crystal itself, this ultimately being manifested by a larger fraction of special grain limits ( fsp = 0.37) in the heat treated sample compared to the "annealed at room temperature" sample ( fsp = 0.26). In addition, as is evident from the inspection of the pole figures generated by the IOM software corresponding to these two samples, which are found in Figures 3 and 4, the heat treatment at 300 ° C (0.42 Tm K) produced a microstructure that exhibits a more homogeneous randomized crystallographic texture, compared to the annealed sample at uncontrolled room temperature. This randomization of the texture is also reflected in the texture intensity (TI) values found in Table 5, which show that the heat treatment controlled at 300 ° C / 2 minutes resulted in a material that shows an intensity value of the texture less than 5 times the random one, while the sample "annealed at room temperature" did not.

Table 4. Bath chemistry and metallization conditions used to electroform a fine grain Cu metallization together with the results of the chemical analysis carried out in the metallization.

Bath chemistry Cu2P2O74H2O 90 g / l K4P2O7400 g / l KH2PO451 g / l KOH 47 g / l KNO315 g / l NH4OH 8.1 g / l H 4P2O7 to adjust the pH

Bath chemistry

Wetting agents, stress relievers

Metallization conditions

Electrolyte temperature: 50 ° C pH: 8.5 Electrolyte agitation speed (normalized for the cathode area): 47 ml / (min.cm 2) Medium current density (Imed) [mA / cm2]: 35 Density Maximum current [mA / cm2]: 70 Working time [ms]: 20 Standby time [ms]: 20 Reverse pulse working time [ms]: 0 Maximum current density of reverse pulse [mA / cm2]: 0 Metallization time [h] 16

Chemical analysis of materials

Element

concentration by weight (ppm)

S

8.8

P

<50

OR

<50

C

121

Table 5. Results of the IOM analysis of samples cut from an electroformed fine-grained Cu metallized, a sample having been analyzed immediately after electrodeposition, a second sample was analyzed 8 weeks after electrodeposition and a third sample was analyzed after heat treatment immediately after electrodeposition.

Heat treatment after metallization

Grain size (μm) Texture Intensity Total special (%  29) fsp

None

0.2-0.4 8.3 40 0

Ambient temperature (0.22 Tm K) / 8 weeks

4 5.9 66 0.26

300 ° C (0.42 Tm K) / 2 minutes

3 4.2 77 0.37

EXAMPLE 3

An independent 0.5 mm thick metallized of fine-grained copper precursor material was electroformed in the same manner as described in Example 2. The results of the chemical test of this material are shown in Table 6. It was measured. the average grain size after deposition of the electroformed copper in example 2, being in the range of 200 to 400 nm, and the proportion of the thickness with respect to the grain size in example 2, being in the range of 1250 to 2500. Because the materials were produced in the same manner, the grain size after metallization fsp and texture intensity value data for example 2 are assumed to be the same as for the present example. Samples were then submitted

individual cut from this metallized to thermal treatments of grain growth by immersion in molten salt at 150 ° C (0.31 Tm K), 300 ° C (0.42 Tm K) and 500 ° C (0.57 Tm K) during times ranging from 30 to 40,000 seconds. The evolution of the grain limit character distribution, the preferred crystallographic orientation and the grain size were evaluated using the same 5-orientation image microscopy (IOM) procedure described above and the results are indicated in Table 7. In addition , the same data of fsp and fsp are presented schematically in Figure 5, while the texture intensity data for the same samples are presented in Figure 6. The data for the material after deposition is included in the mark 1 second in the abscissa of figures 5 and 6 for illustrative purposes. Specifically in Table 7 and Figures 5 and 6, it can be seen that at temperatures of grain growth heat treatment of 0.31 Tm K and 10 0.42 Tm K, the grain grain heat treatment during a period 120 s results in significant increases in the fsp of the material from 40 to 75% (0.31 Tm K) and 70% (0.42 Tm K). The corresponding texture intensity values fell from 8.2 to 3.0 (0.31 Tm K) and 2.7 (0.42 Tm K) and the average grain size values increased from 0.5 to 1, 5 microns (0.31 Tm K) and 2 microns (0.42 Tm K). Other increases in the heat treatment time of grain growth resulted in the leveling of fsp at fsp = 81% (0.31 Tm K) and 15 fsp = 71 to 74% (0.42 Tm K), with values of corresponding texture intensity of 3.5 (0.31 Tm K) and 3.1 (0.42 Tm K) and average grain size values of 2 microns (0.31 Tm K) and 2.8 microns (0, 42 Tm K), respectively. In the case where a grain growth heat treatment temperature of 0.57 Tm K is selected, a maximum fsp of 74% is achieved in a grain growth heat treatment time of between 30 and 120 s with a corresponding texture intensity value between 4.2 and 4.9 and an average grain size between 4.1 and 4.4 µm. Extending the heat treatment time of grain growth beyond 120 seconds to 0.57 Tm K results in a decreased fsp, while the texture intensity value ultimately increases to 15 and the average grain size increases Ultimately at 7 μm. This example illustrates how the temperature and time parameters of grain growth heat treatment can be determined appropriately to achieve the special grain limit fraction, texture intensity values, and desired average grain size values. Similar results are expected when the metallic material comprises Ni or Fe or Cu alloys,

Ni and Fe.

Table 6. Results of the chemical analysis carried out on the precursor material of example 3.

Chemical analysis of materials

Element

concentration by weight (ppm)

S

<5

P

<5

OR

<20

C

<20

Table 7. Results of the IOM analysis of samples cut from a fine grain electroformed Cu metallized and heat treated at varying temperatures and times.

Heat treatment after metallization

Grain size (μm) Texture Intensity Total Special ( 29) fsp (%)

None

0.5 8.2 40 0

150 ° C (0.31 Tm K) / 120 seconds

1.5 3.0 75 0.35

150 ° C (0.31 Tm K) / 4000 seconds

1.8 2.8 81 0.41

150 ° C (0.31 Tm K) / 40 000 seconds

2.0 3.5 81 0.41

300 ° C (0.42 Tm K) / 120 seconds

2.0 2.7 70 0.30

300 ° C (0.42 Tm K) / 4000 seconds

2.7 3.6 71 0.31

300 ° C (0.42 Tm K) / 40 000 seconds

2.8 3.1 74 0.34

500 ° C (0.57 Tm K) / 30 seconds

4.1 4.2 74 0.34

500 ° C (0.57 Tm K) / 120 seconds

4.4 4.9 74 0.34

500 ° C (0.57 Tm K) / 4000 seconds

4.8 4,5 67 0.27

500 ° C (0.57 Tm K) / 40 000 seconds

7.0 fifteen 64 0.24

EXAMPLE 4

Metallized independent of fine grain copper precursor material were electroformed at thickness values

5 variables in the same manner as described in example 2. The metallization time was used to control the thickness of the metallization. The results of the chemical test of the material produced under these conditions are shown in Table 8. The average grain size after deposition of the electroformed copper was measured to be 600 nm. Using the data determined for the material of example 2, the fsp after deposition was 40% while the IT value was 8.3. Individual samples were then subjected to thermal growth treatments

10 grain per immersion in molten salt at 300 ° C (0.42 Tm K) for 120 seconds. The evolution of the distribution of the grain limit character, the preferred crystallographic orientation and the grain size were evaluated using the same procedure for image orientation microscopy (IOM) described above and the results are indicated in Table 9. see that the thin sheets (<20 μm) with an average grain thickness / size ratio of less than 30 did not show the desired fsp increase of more than 0.3. On the other hand, it was determined that the

The average thickness / size of the 100 µm thick sample was 59, while the average thickness / size ratio of the 500 µm thick sample was determined to be 250. After heat treatment, the samples 100 and 500 μm thick showed the desired increase in fsp of 0.37 and 0.45, respectively. Similar results are expected when the metallic material comprises Ni or Fe or Cu, Ni and Fe alloys.

20 Table 8. Results of the chemical analysis carried out on the precursor material of example 4.

Chemical analysis of materials

Element

concentration by weight (ppm)

S

0.2

P

3.1

OR

<20

C

<20

Table 9. Results of the IOM analysis of electroformed fine grain Cu metallized of variable thickness heat treated at 300 ° C (0.42 Tm K) for 120 seconds.

Thickness (μm)

Grain size (μm) Thickness / grain size Texture intensity Total special (%  29) fsp

10

1.0  10 2.2 61 0.21

16

1.2 13 2.5 64 0.24

100

1.7 59 3.2 77 0.37

500

2.0 250 2.8 85 0.45

EXAMPLE 5

30 Two 5.3 mm thick fine grain spray targets, labeled "A" and "B", were electroformed on a polished Ti cathode (25 cm2) in a bath based on copper pyrophosphate (60 tank I) using OFHC copper as the anode material. The metallization current was supplied by a Dynanet ™ PDPR 40-100-400 pulse power supply (Dynatronix, Amery, Wisconsin, USA). The electrolyte and the conditions of

35 electroplating used to produce both together with the results of the chemical test of one of these targets of

Electrodeposited sprays are contained in Table 10. Using the data determined for the material of Example 2, the fsp after deposition was 40%, while the TI value was 8.3, however the impurity levels achieved they were inferior due to an improved purification by modeling the chemistry of the electrodeposition procedure of the spray target. Immediately after metallization, both targets were immersed for 2 minutes in a molten salt bath heated to 300 ° C (0.42 Tm K). The above-mentioned FEGSEM microscope was then used to characterize the average grain size, crystallographic texture and frequency of "special" grain boundaries (29) of the targets, and the results of this analysis are indicated in the table. eleven.

A conventionally prepared commercially available copper spray target was purchased and copper films were sprayed onto silicon wafers using both "A" and "B" targets, next to the commercially available polycrystalline Cu target, identically . The back of the targets were treated with fat from

Vacuum Press L ™ in order to seal the O-ring for water cooling. The wafers were then oxidized

silicon and cleaned before deposition. There was an initial incineration time on all targets before deposition on silicon wafers. The size of the silicon wafers was 100 mm in diameter. The film spray conditions were: Spray pressure = 3 mT; spray power per DC = 100 W; DC spray current = 0.19-0.23 A and DC 420-550 V spray voltage. The bias voltage was kept constant at -70 V for all deposition cycles. The target thickness for deposition was 100 nm. After spraying, the sprayed films were characterized using electrodeposited targets "A" and "B" and the results were compared with the sprayed film using the conventional target. This characterization of the films is achieved by 49-point laminar resistance measurements that were made on the sprayed films using a standard resistivity mapping system.

Under the same spray conditions, for a constant average pulverized film thickness of 100 nm, it was observed that the sprayed films using the "A" and "B" targets showed a reduction in sheet resistance of more than 40% compared with the conventional spray target. This behavior is evident from the laminar resistance maps contained in Figure 7A, where the laminar resistance of the pulverized films has been quantified using the electrodeposited targets "A" and "B" and compared with the laminar resistance of the pulverized film using the conventional target. The sheet resistance of pulverized films using the "A" and "B" targets ranges from about 1.3 to 2.3 ohms per square, while the sheet resistance of the sprayed film using the reference target ranges from 2.3 to almost 5.4 ohms per square. The numerical scale is given in ohms per square, which is the standard unit system for sheet resistance used in the industry.

In addition to the sheet resistance of the sprayed film, the sprayed sample targets themselves were inspected by scanning electron microscopy (SEM) after the spraying service. It was found that electrodeposited targets "A" and "B" exhibited improved pulverized target uniformity when compared to the conventional target standard. This behavior is evident from the SEM photomicrographs of the target surfaces contained in Figure 7B. The evidence of intergranular degradation, which ultimately leads to the fall of grains, can be seen in the photomicrograph of the conventional Cu target surface, while this is not observed in the case of electrodeposited targets "A" and "B ". In addition to the SEM photomicrographs of the target surfaces, the results of the surface profilometer measurements made on these same target target surfaces after the equivalent spray service have also been included in Figure 7C. The average surface roughness of the target "A" was measured after the spraying service, which was 0.83 μm, while that of the target "B", which was 0.74 mm, was measured, which is a improvement of more than 60% when compared to the average surface roughness of the standard conventional target after the same degree of spray service, which was determined to be 2.18 μm. As both the SEM inspection of the target surfaces after service and the average surface roughness measurements made on these spray target surfaces demonstrate, the electrodeposited spray targets "A" and "B" exhibit an improvement of more than one 50% of the spray uniformity, which results in an equivalent improved longevity when compared to conventional commercially available large grain spray targets. Similar results are expected when the metallic material comprises Ni or Fe or Cu, Ni and Fe alloys.

Table 10. Bath chemistry and metallization conditions used to electroform two fine-grained Cu spray targets together with the results of the chemical analysis carried out on one of the spray targets.

Bath chemistry Cu2P2O74H2O 90 g / l K4P2O7 400 g / l KH2PO4 51 g / l KOH 47 g / l KNO315 g / l NH4OH 8.1 g / l H 4P2O7 to adjust the pH Wetting agents, stress relievers

Metallization conditions

Electrolyte temperature: 50 ° C pH: 8.5 Electrolyte agitation speed (normalized for the cathode area): 372 ml / (min.cm2) Medium current density (Imed) [mA / cm2]: 35 Density of maximum current [mA / cm2]: 70 Service time [ms]: 20 Standby time [ms]: 20 Service time per inverse pulse [ms]: 0 Maximum current density per inverse pulse [mA / cm2]: 0 Metallization time [h] 160

Chemical analysis of materials

Element

concentration by weight (ppm)

S

0.36

P

1.5

OR

10

C

20

Table 11. Results of the IOM analysis of electroformed fine grain Cu spray targets heat treated immediately after electrodeposition and a conventional standard spray target.

Spray target

Grain size (μm) Texture Intensity Total Special ( 29)

Sample A / B

4 3.3 77

Conventional standard

40 3.2 41

EXAMPLE 6, not according to the invention:

10 An independent 0.06 mm thick metallized nickel of fine grain nickel was electroformed on a polished Ti cathode (10 cm2) in a standard Ni Watts bath (2.5 l tank) without sulfur-containing grain refiners and using INCO ™ Ni R-rounds as anode material. The metallization current was supplied by an ATC ™ 6101 PT pulse power supply (Dynatronix, Amery, Wisconsin, USA). The electrolyte and the conditions of

15 used electroplating are indicated in table 12 together with the results of chemical testing of the material. The microstructure after deposition could not be characterized by IOM because the grain size of this material (50 nm) was below the resolution limit of the IOM technique. Figure 8 is a transmission electron microscopy (TEM) image illustrating the microstructure of pure nickel after electrodeposition. It was determined by TEM that the average grain size after deposition of electroformed nickel was

20 approximately 50 nm. The ratio of thickness to grain size was determined to be approximately 1200. After metallization, a sample of nickel plating was cut and heat treated at 800 ° C (0.62 Tm K) for 2 minutes. An IOM photomicrograph of this structure is found in Figure 9. The distribution of the grain limit character, grain size and preferential crystallographic orientation were evaluated using the same orientation microscopy (IOM) procedure described above and

results are indicated in table 13 below. For the after metallized sample, the 'special' grain limit content is estimated to be approximately 20% (see DH Warrington and M. Boon, Acta Metall. 23, 599 (1975) and EG Doni, G. Palumbo and KT Aust, Scripta Metall. Mat. 24. 2325 (1990)). It can be seen that the use of a controlled deliberate annealing treatment at a relatively high temperature (800 ° C = 0.62 Tm 5 (K)) for a short period of time (2 minutes) resulted in the effective sustained replacement of “general” grain limits of higher energy due to “special” grain limits that have a higher atomic order close to that of the crystal itself, this ultimately being manifested by a high fraction of special grain limits (fsp = 61%) in the heat treated sample at 800 ° C (0.42 Tm K). In addition, as is evident from the inspection of the pole figure found in figure 10 and the texture intensity value (TI = 2.7) in table 13

10 generated by the IOM software corresponding to this sample, the heat treatment at 800 ° C (0.42 Tm K) produced a microstructure that shows a texture intensity value less than 5 times the random one.

Table 12: Bath chemistry and metallization conditions used to electroform a fine grain Ni metallized together with the results of the chemical analysis carried out in the metallization. fifteen

Bath chemistry NiSO46H2O 300 g / l NiCl26H2O 45 g / l H3BO3 45 g / l

Metallization conditions

Electrolyte temperature: 60 ° C pH: 4.0 Electrolyte stirring speed (normalized for the cathode area): 6000 ml / (min.cm2) Average current density (Imed) [mA / cm2]: 200

Metallization conditions Maximum current density [mA / cm2]: 2000 Service time [ms]: 5 Standby time [ms]: 45 Service time per inverse pulse [ms]: 0 Maximum current density per inverse pulse [mA / cm2]: 0 Metallization time [min]: 20

Chemical analysis of materials

Element

concentration by weight (ppm)

S

10

P

50

OR

50

C

100

Table 13 Results of the IOM analysis of samples cut from an electroformed fine grain Ni metallized and heat treated at 800 ° C for 2 minutes.

Heat treatment after metallization

Grain size (μm) Texture Intensity Total Special ( 29) fsp

None

0.05 Not measurable twenty* 0

800 ° C / 2 min

2 2.7 61 0.41

twenty

Although the applicant's teachings are described in conjunction with various embodiments, it is not intended that the applicant's teachings limit such embodiments. The applicant's teachings encompass various alternatives, modifications and equivalents, as will be appreciated by those skilled in the art.

25

Claims (9)

1. A procedure for preparing an article, the procedure comprising the steps of: 5 a) electrodeposition of a metallic material comprising copper from an aqueous electrolyte comprising copper pyrophosphate using direct current (DC) metallization, pulse current (PP) and / or reverse pulse (PR) metallization using a density of average current that varies from 5 to 10 000 mA / cm2, a service time per direct pulse that varies from 0.1 to 500 ms, a rest time that varies from 0 to 10 000 ms, a service time per pulse inverse that varies from 0 to 500 ms, a 10 maximum direct current density that varies from 5 to 10 000 mA / cm2, a maximum inverse current density that varies from 5 to 20 000 mA / cm2, a frequency that varies from 0 to 1000 Hz and a duty cycle that varies from 5 to 100%, to form or at least partially metallize an article, the metallic material having 15 i) an average grain size between 4 nm and 5 μm, and ii) an impurity content of less than 20 ppm by weight of S, less than 50 ppm by weight of O, less than 50 ppm by weight of P and less than 300 ppm by weight of C; Y 20 b) heat treatment of the electrodeposited metal material at a temperature between 0.25Tm and 0.7Tm K for a period of time between 1 second and 75 hours to induce grain growth in the metal material such that at least one portion of metallic material shows an increase of at least 0.3 of the fraction of the special grain limit and an intensity value of the crystallographic texture of less than 7.5 times the random. 2. The method of claim 1, wherein the temperature and time of the heat treatment are sufficient to induce at least a three-fold increase in the average grain size of the metallic material. 3. The method of claims 1 or 2, wherein the metallic material is electrodeposited at a thickness 30 of at least 30 times the average grain size of the metallic material. 4. The method of any one of claims 1 to 3, wherein after step (b), at least a part of the metal material has a special grain limit content of at least 50%. The method of claim 1, wherein the article is a spray target. 6. The method of claim 1, wherein the article is a shaped loading liner. 7. The method of any one of claims 1 to 4, wherein, in step (a), the metallic material has an average grain size between 200 nm and 400 nm. 8. The method of claim 7, wherein the metallic material is Cu and wherein, in step (b), the deposited metallic material is heat treated at a temperature between 150 ° C and 500 ° C for a period long enough to induce an increase of at least three times the average grain size of the 45 metallic material. 9. The method of claim 1, wherein the article is suitable for use in nuclear environments. 10. The method of claim 1, wherein the article is suitable for use in gas turbines. fifty