Coating source

Abstract

A process for producing a coating source for physical vapour deposition provides the coating source with a target layer formed of an at least two-phase composite which contains a metallic phase and at least one further phase and a mechanical stabilizing layer which is joined to the target layer on one side of the target layer. A first powder mixture which corresponds in terms of its composition to the at least two-phase composite and a second powder mixture which corresponds in terms of its composition to the mechanical stabilizing layer are densified hot in superposed layers. A coating source for physical vapour deposition is also provided.

Claims

1. A process for producing a coating source for physical vapour deposition, the process comprising the following steps: providing a first powder mixture having a composition corresponding to a target layer formed of an at least two-phase composite containing a metallic phase and at least one further phase; providing a second powder mixture having a composition corresponding to a mechanical stabilizing layer being joined to one side of the target layer at a joining zone having an increasing concentration of particles of the at least one further phase of the at least two-phase composite going from the mechanical stabilizing layer in a direction toward the target layer without formation of an interface; and hot-densifying the first and second powder mixtures in superposed layers.

2. The process according to claim 1, which further comprises carrying out the hot-densifying step by hot-pressing the superposed layers.

3. The process according to claim 1, which further comprises carrying out the hot-densifying step by at least one of supplying the superposed layers with an electric current or inductively heating the superposed layers.

4. The process according to claim 1, which further comprises carrying out at least one of the steps of providing the first or second powder mixture as only a predensified intermediate compact, and effecting a final densification and joining by the hot-densifying step.

5. The process according to claim 1, which further comprises using titanium or a titanium alloy as the metallic phase of the at least two-phase composite.

6. The process according to claim 1, which further comprises providing a material for the metallic phase of the at least two-phase composite and a material of the mechanical stabilizing layer as the same metal to an extent of at least 80 at.%.

7. The process according to claim 1, which further comprises providing the further phase in a proportion of more than 25 percent by volume of the at least two-phase composite.

8. The process according to claim 5, which further comprises using an element other than at least one of titanium or a titanium compound as the further phase.

9. The process according to claim 1, which further comprises placing the first and second powder mixtures above one another with full areas of the first and second powder mixtures adjoining one another.

10. A coating source for physical vapour deposition, the coating source comprising: a target layer formed of an at least two-phase composite containing a metallic phase and at least one further phase, said metallic phase and all further phases present having melting points above 1000 C.; a mechanical stabilizing layer; and a joining zone joining said mechanical stabilizing layer to one side of said target layer, said joining zone having an increasing concentration of particles of said at least one further phase of said at least two-phase composite going from said mechanical stabilizing layer in a direction toward said target layer without formation of an interface.

11. The coating source according to claim 10, wherein said metallic phase of said at least two-phase composite includes titanium or a titanium alloy.

12. The coating source according to claim 10, wherein said metallic phase of said at least two-phase composite and said mechanical stabilizing layer are formed of materials being the same metal to an extent of at least 80 at.%.

13. The coating source according to claim 10, wherein said further phase is present in a proportion of more than 25 percent by volume of said at least two-phase composite.

14. The coating source according to claim 11, wherein said further phase is formed of an element other than at least one of titanium or a titanium compound.

15. The coating source according to claim 10, wherein said mechanical stabilizing layer is formed of the same metallic material forming said metallic phase of said target layer and is at least substantially free of particles of said further phase of said at least two-phase composite.

16. The coating source according to claim 10, wherein said mechanical stabilizing layer is formed of an at least two-phase composite.

Description

BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWING

(1) FIG. 1 a metallographic polished section,

(2) FIG. 2a and FIG. 2b a further metallographic polished section with grain boundary etching

(3) FIG. 3 a coating source (target)

(4) FIG. 4 a pressing tool.

DESCRIPTION OF THE INVENTION

(5) FIG. 1 shows a metallographic polished section of a joining zone 4 of a coating source 1 according to the invention, via which a target layer 2 (in this case TiSi 70/30 at. %) and a mechanical stabilizing layer 3 (in this case titanium) are joined.

(6) The figure naturally shows only sections of the target layer 2, of the joining zone 4 and of the stabilizing layer 3. The arrows at the right-hand margin of the picture indicate the orientation of the image section shown. The arrow having the reference symbol 2 points in the direction in which the target layer 2 extends. The arrow having the reference symbol 3 points in the direction in which the stabilizing layer 3 extends.

(7) The widths of the brackets characterizing the respective layers do not have to correspond to the actual layer thicknesses but instead serve for identification of the respective layers.

(8) The further phase P of the at least two-phase composite embedded in the metallic phase M as first phase of the target layer 2 can clearly be seen. The metallic phase M thus forms the matrix here. In the example shown, the phase M of the target layer 2 corresponds to the stabilizing layer 3. In other words, the mechanical stabilizing layer 3 consists of the same material which forms the phase M of the target layer 2.

(9) The further phase P in the present example is a titanium silicide and is embedded in a titanium matrix formed by the metallic phase M.

(10) FIG. 2a and FIG. 2b in each case show a metallographic polished section of the joining zone 4 of a coating source 1 according to the invention with grain boundary etching for the example of a TiSi 70/30 at. % material on a titanium stabilizing layer 3.

(11) The grain boundaries are made visible by grain boundary etching. It is therefore possible to see the shape and orientation of the individual grains here. Note may be taken of the size scale, recognizable from the size bar, which is different from FIG. 1.

(12) The images in FIGS. 2a and 2b differ in that in FIG. 2b the grain boundaries of the TiSi grains, which correspond to the further phase P, have been outlined with a bold black line to distinguish them better. Otherwise, FIG. 2b corresponds to FIG. 2a.

(13) The orientation of the metallographic polished section is made clear by the arrows at the right-hand margin of the page. The arrow having the reference symbol 2 points in the direction in which the target layer 2 extends. The arrow having the reference symbol 3 points in the direction in which the stabilizing layer 3 extends.

(14) The individual TiSi grains (phase P) are embedded in the metallic phase M. It may be remarked that the lines of the reference symbols are directed by way of example at individual grains of the phase P or of the metallic phase M. Naturally, the phase P and the metallic phase M consist of many grains.

(15) In the present materials system, the rather roundish grains of the phase P can be distinguished readily in respect of their shape from the angular grains of the metallic phase M.

(16) It can be seen that the microstructure of the stabilizing layer 3 goes over continuously into the metallic phase M of the target layer 2. The individual Ti grains in the stabilizing layer 3 and also in the metallic phase M of the target layer 2 can be recognized by the characteristic twinning in the interior of the grains. In the joining zone, an increasing concentration of particles of the further phase P (here the TiSi grains) going from the material of the stabilizing layer 3 in the direction to the target layer 2 can be seen.

(17) FIG. 3 shows a perspective view of a coating source 1 according to the invention. In the example shown, the stabilizing layer 3 can be distinguished visually from the target layer 2. The step on the circumference in the coating source 1 here does not correspond to the transition of target layer 2 into the stabilizing layer 3. Bayonet projections 31, which aid positioning of the coating source 1 in a coating plant, can be seen on the stabilizing layer 3.

(18) FIG. 4 schematically shows a pressing tool 5 for producing a blank for a coating source 1 by the process of the invention. The pressing tool 5 has an upper punch and a lower punch (51, 52) and a heating device 53.

(19) A first powder mixture 6 which corresponds in terms of its composition to the target layer 2 and a second powder mixture 7 which corresponds in terms of its composition to the mechanical stabilizing layer 3 are present as layers in the pressing tool 5. Densification is effected axially, as indicated by the arrow.

LIST OF REFERENCE SYMBOLS USED

(20) 1 Coating source

(21) 2 Target layer

(22) 3 Stabilizing layer

(23) 31 Bayonet projection

(24) 4 Joining zone

(25) 5 Pressing tool

(26) 51 Upper punch

(27) 52 Lower punch

(28) 53 Heating device

(29) 6 first powder mixture

(30) 7 second powder mixture

(31) M Metallic phase

(32) P further phase