METHOD FOR BRAZING TITANIUM ALLOY COMPONENTS WITH ZIRCONIA-BASED CERAMIC COMPONENTS FOR HOROLOGY OR JEWELLERY

Abstract

A method for brazing a first ceramic component and a second metal alloy component, to make a structural or external timepiece element, a zirconia-based ceramic is chosen for the first component and a titanium alloy for the second component, a first recess is made inside the first component, set back from a first surface in a junction area with a second surface of the second component, braze material is deposited on this first surface and inside each recess, the second surface is positioned in alignment with the first surface to form an assembly, this assembly is heated in a controlled atmosphere to above the melting temperature of the braze material, in order to form the braze in the junction area.

Claims

1. A method for brazing a first ceramic component and a second metal alloy component to make a structural and/or external timepiece element, the method comprising: choosing a zirconia-based ceramic for said first component, and choosing a titanium alloy for said second component, making at least one first recess inside the first component, set back with respect to a first bearing surface in a junction area with a second bearing surface of the second component, depositing braze material on the first bearing surface and inside each recess, positioning the second surface in alignment with the first surface to form an assembly, heating said assembly in a controlled atmosphere at a higher temperature than the melting temperature of the braze material, to form the braze of said second component to said first component in the junction area, and making at least one said second bearing surface in a second component with at least two basic surfaces, secant on at least a second line of intersection located in said junction area.

2. The brazing method according to claim 1, wherein said brazing is carried out in at least one junction area, between at least a first bearing surface comprised in said first component, and at least a second bearing surface comprised in said second component, which is at least partially complementary to said first bearing surface, and wherein said first component and/or respectively said second component is arranged, by making, set back from its said first bearing surface and/or respectively its said second bearing surface, at least one first recess of the tapered drilling or slit or groove type, and/or respectively a second recess, forming a receptacle arranged to allow a braze material to penetrate deep inside said first component, and/or respectively said second component, set back said from first bearing surface, and/or respectively said second bearing surface, and to facilitate the mechanical adhesion of said braze material inside said first component, and/or respectively said second component, in that there is chosen said braze material compatible at least with said titanium alloy, in that said first component and/or respectively said second component is prepared by depositing braze material on said first bearing surface and inside each said first recess set back from said first bearing surface, and/or respectively on said second bearing surface and inside each said second recess set back from said second bearing surface, and wherein said second surface of said second component is positioned in alignment with said first surface of said first component to form an assembly, and that wherein said assembly is heated in a controlled atmosphere to a temperature higher than or equal to the melting temperature of said braze material, to form the braze between said second component and said first component in said junction area.

3. The brazing method according to claim 1, wherein said first component is arranged by making at least a first recess of the tapered drilling or slit or groove type, set back from its said first bearing surface, said first recess forming a receptacle arranged to allow a braze material to penetrate deep inside said first component, set back from said first bearing surface, and to facilitate the mechanical adhesion of said braze material inside said first component, wherein there is chosen said braze material compatible at least with said titanium alloy, wherein said first component is prepared by depositing braze material on said first bearing surface and inside each said recess set back from said first bearing surface, wherein said second surface of said second component is positioned in alignment with said first surface of said first component thus prepared, to form an assembly, and wherein said assembly is heated in a controlled atmosphere to a temperature higher than or equal to the melting temperature of said braze material, to form the braze between said second component and said first component in said junction area.

4. The method according to claim 1, wherein at least said first bearing surface of said first component is made, with at least two first basic surfaces, secant on at least a first line of intersection, and at least one said first recess is made on said first line of intersection.

5. The method according to claim 2, wherein at least one said second recess is made on said second line of intersection.

6. The method according to claim 1, wherein said assembly is mechanically held tightly pressed in the vicinity of the said junction area during said brazing operation.

7. The method according to claim 1, wherein said braze material is chosen in the form of a brazing paste, which is inserted under pressure at least in each said first recess, set back from said first surface.

8. The method according to claim 1, wherein at least one said first recess is made with a neck in proximity to said first surface, wherein the cross-section of said neck is smaller than the cross-section of the bottom of said first recess facing said first surface, to form a key mechanically holding said second component to said first component after said brazing operation.

9. The method according to claim 1, wherein a single direction of insertion (DI) of second component is determined for the alignment thereof with said first component, and in wherein at least one said first recess is made oblique or perpendicular to said direction of insertion (DI).

10. The method according to claim 1, wherein a single direction of insertion (DI) of said second component is determined for the alignment thereof with said first component, and in wherein said first surface and said second surface are made with a radial clearance (JR) between them, in the free state before the deposition of braze material, said radial clearance (JR) is comprised between 0.010 mm and 0.040 mm at the radius, perpendicularly to said direction of insertion (DI).

11. The method according to claim 10, wherein said first surface and said second surface are made with a radial clearance (JR) between them, in the free state before the deposition of braze material, which radial clearance (JR) is comprised between 0.015 mm and 0.025 mm at the radius, perpendicularly to said direction of insertion (DI).

12. The method according to claim 1, wherein there is chosen as said braze material a braze material that is suitable for brazing tungsten carbide on steel.

13. The method according to claim 1, wherein said braze material is chosen to include copper, manganese and nickel, and to be cadmium free, with extra-fine grain size, and to include a binder for brazing in a controlled atmosphere furnace at a temperature comprised between 1000 C. and 1100 C.

14. The method according to claim 1, wherein at least one said first recess is made during the fabrication of said first ceramic component.

15. The method according to claim 1, wherein at least one said first recess is completely machined or finish-machined using a laser.

16. The method according to claim 1, wherein at least one said first recess is completely machined or finish-machined mechanically using a tool or grinding wheel.

17. The method according to claim 1, wherein a plurality of discontinuous first recesses is made in said junction area.

18. The method according to claim 1, wherein there is chosen as said titanium alloy grade 5 titanium which includes, in % according to ASTM F136, from 0.00 to 0.08 C, from 0.0 to 0.3 Fe, from 0.0000 to 0.0125 H, from 0.00 to 0.05 N, from 0.0 to 0.2 O, from 5.50 to 6.75 Al, from 3.5 to 4.5 V, from 0.0 to 0.1 OE (other elements, each), from 0.0 to 0.4 TO (total other elements), and the remainder of Ti.

19. The method according to claim 1, wherein zirconia-based ceramic is chosen to contain: at least one stabilizer chosen from the group of oxides comprising yttrium oxide, magnesium oxide, and calcium oxide, alone or in combination; at least one element intended to create a vitreous phase, and chosen from the group comprising silicon oxide, aluminium oxide, lithium oxide and yttrium oxide, alone or in combination; an oxide powder used as pigment; and a zirconia powder forming the remainder to 100% by weight.

20. The method according to claim 19, wherein said zirconia-based ceramic is chosen to contain: 3 to 20% by weight of at least one stabilizer chosen from the group of oxides comprising yttrium oxide, magnesium oxide and calcium oxide, alone or in combination; 0.1 to 5% by weight of at least one element intended to create a vitreous phase, and chosen from the group comprising silicon oxide, aluminium oxide, lithium oxide and yttrium oxide, alone or in combination; 1 to 10% by weight of an oxide powder used as pigment; and a zirconia powder forming the remainder to 100% by weight.

21. A watch comprising at least one structural and/or external element made by the method according to claim 1.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0024] Other features and advantages of the invention will appear upon reading the following detailed description, with reference to the annexed drawings, in which:

[0025] FIG. 1 represents a schematic plan view of a first untreated component, formed here by a zirconia-based ceramic watch case middle.

[0026] FIG. 2 represents a schematic sectional view in a radial plane, of a detail of the case middle of FIG. 1, on a first bearing surface for receiving a second component, which here is a ring.

[0027] FIG. 3 represents, in a similar manner to FIG. 2, an arrangement of this case middle according to the invention, with a first recess in its thickness, set back from the first bearing surface.

[0028] FIG. 4 shows, in a similar manner to FIG. 3, the braze deposited in this recess.

[0029] FIG. 5 represents, in a similar manner to FIG. 2, the second component, here consisting of a titanium alloy ring, in particular a grade 5 titanium alloy, and comprising a second bearing surface arranged to cooperate in an at least partially complementary manner with the first bearing surface of the case middle, in a junction area.

[0030] FIG. 6 represents, in a similar manner to FIG. 5, a variant preparation of the second component, with a second recess in its thickness, set back from its second bearing surface.

[0031] FIG. 7 represents, in a similar manner to FIG. 4, the insertion of this ring, in a direction of insertion, on this case middle, to create an assembly ready to be placed in the furnace.

[0032] FIG. 8 represents, in a similar manner to FIG. 7, this assembly after the brazing operation has been carried out in a controlled atmosphere furnace, particularly under argon atmosphere.

[0033] FIG. 9 represents, in a similar manner to FIG. 1, this case middle with four recesses in proximity to the horns.

[0034] FIG. 10 represents, in a similar manner to FIG. 3, a first recess with a peaked profile, oblique with respect to the direction of insertion, and also oblique with respect to the basic surfaces forming the first bearing surface of the case middle, after, for example, laser machining.

[0035] FIG. 11 represents, in a similar manner to FIG. 9, the case middle once the braze material is deposited in the recess, and on the first bearing surface a wave pattern.

[0036] FIG. 12 represents, in a similar manner to FIG. 10, a first recess with a rounded profile, perpendicular with respect to the direction of insertion, and also oblique with respect to one of the basic surfaces forming the first bearing surface of the case middle, after, for example, mechanical machining of an undercut.

[0037] FIG. 13 represents, in a similar manner to FIG. 10, a first recess with a profile wherein the neck is narrower than bottom of the recess.

[0038] FIG. 14 is a block diagram representing a watch comprising at least one structural and/or external element made by the method according to the invention.

DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS

[0039] The invention concerns a method for brazing a first ceramic component 10 and a second metal alloy component 20, to make a structural and/or external timepiece element 100.

[0040] According to the invention, a zirconia-based ceramic is chosen for first ceramic component 10, and a titanium alloy is chosen for second metal alloy component 20.

[0041] Indeed, brazing between ceramics suitable for external timepiece components and metal alloys is a difficult operation, and numerous tests carried out have highlighted the essential nature of close thermal behaviour between the ceramic and the metal alloy.

[0042] The method explained hereinafter can be used for other ceramics, like silicon nitride-based ceramics, or others, and/or for other alloys like stainless steels or other alloys, but with very different expansion and shrinkage behaviour, which impairs the quality of the brazing operation, which explains the deliberate choice to pair the zirconia-based ceramic with a titanium alloy, to produce a good quality braze, and especially excellent adherence over time.

[0043] Zirconia is a material with many advantageous properties but is totally non-reactive to the other elements. Consequently, brazing, whose principle is based on reactions between the elements (braze material and components), is a very difficult operation to perform. Selecting a suitable metal alloy, compatible with horological constraints in terms of health safety, strength, resistance to ageing, quality of appearance, is not obvious. Since brazing occurs at the melting temperature of the braze material, the thermal expansion coefficients of the two assembled elements must be very close to one another, as is the case of zirconia and titanium, to avoid any risk of breakage or deformation of the components.

[0044] Titanium alloys, at least those devoid of nickel, satisfy the aforementioned conditions, and are suitable for brazing, assembled with a zirconia-based ceramic, according to the invention.

[0045] With other ceramics and other metal alloys, the problem is similar, but assembly by means of brazing is impossible in most cases, or at least very difficult to implement, although the operating mode of the method disclosed hereinafter is theoretically possible for other ceramic/metal alloy pairs.

[0046] More particularly, according to the invention, at least a first recess 4 is made inside first component 10, set back with respect to a first bearing surface 1 in a junction area 3 with a second bearing surface 2 of second component 20, braze material 5 is deposited on this first bearing surface 1 and inside each recess 4, second surface 2 is positioned in alignment with first surface 1 to form an assembly, and this assembly is heated in a controlled atmosphere to a temperature higher than the melting temperature of braze material 5, to form the braze between second component 20 and first component 10 in junction area 3.

[0047] More particularly, this brazing method is implemented, in at least one junction area 3, between at least a first bearing surface 1 comprised in a first zirconia-based ceramic component 10, and at least a second bearing surface 2 comprised in a second titanium alloy component 20, in order to produce such an element 100. This second bearing surface 2 is at least partially complementary to first bearing surface 1.

[0048] According to the invention, first component 10 and/or respectively second component 20 is arranged, by making, set back from its first bearing surface 1, and/or respectively its second bearing surface 2, at least a first recess 4 of the tapered drilling or slit or groove type, and/or respectively a second recess 7, forming a receptacle arranged to allow a braze material 5 to penetrate deep inside first component 10, and/or respectively of second component 20, set back from first bearing surface 1, and/or respectively second bearing surface 2, and to facilitate the mechanical adhesion of braze material 5 inside first component 10, and/or respectively second component 20.

[0049] To this end, there is chosen a braze material 5 compatible at least with the titanium alloy of the second component, in particular but not limited to a grade 5 titanium alloy.

[0050] First component 10 and/or respectively second component 20 is prepared by depositing braze material 5 on first bearing surface 1 and inside each first recess 4 set back from first bearing surface 1, and/or respectively on second bearing surface 2 and inside each second recess 7 set back from second bearing surface 2.

[0051] Second surface 2 of second component 20 is positioned in alignment with first surface 1 of first component 10, to form an assembly. This assembly is then heated in a controlled atmosphere to a temperature higher than or equal to the melting temperature of braze material 5, to form the braze between second component 20 and first component 10 in junction area 3.

[0052] Advantageously, several recesses 4 are made, geometrically distributed in junction area 3 to perform a kind of stapling of second component 20 to first component 10. For example, in order to braze a ring around a shoulder of a case middle, at least three, or more particularly, at least four such recesses 4 are made to ensure good relative adherence of the two components.

[0053] In a variant, a plurality of discontinuous first recesses 4 and/or respectively of second recesses 7, are made in junction area 3.

[0054] In another variant, a single continuous recess 4 is made in junction area 3. More particularly, this single recess 4 follows a closed contour around first surface 1 of first component 10.

[0055] In a particular implementation, first recesses 4 are made only in first component 10, in order to keep the most possible material of second component 20 in junction area 3. First component 10 is then arranged by making at least a first recess 4 of the tapered drilling or slit or groove type, set back from its first bearing surface 1, first recess 4 forming a receptacle arranged to allow a braze material 5 to penetrate deep inside first component 10, set back from first bearing surface 1, and to facilitate the mechanical adhesion of braze material 5 inside first component 10. A braze material 5 compatible with the titanium alloy is chosen. First component 10 is prepared by depositing braze material 5 on first bearing surface 1 and inside each first recess 4 set back from first bearing surface 1. Second surface 2 of second component 20 is positioned in alignment with first surface 1 of the first component 10 thus prepared, to form an assembly. This assembly is heated in a controlled atmosphere to a temperature higher than or equal to the melting temperature of braze material 5, to form the braze between second component 20 and first component 10 in junction area 3.

[0056] More particularly, at least a first bearing surface 1 of first component 1 is made, with at least two first basic surfaces 11, 12, which are secant on at least a first line of intersection 13, and at least a first recess 4 is made on a first line of intersection 13. For example, as seen in FIGS. 8 and 9, a first basic surface 11 is a plane surface, a second basic surface 12 is cylindrical, and intersection line 13 is a circle, and recesses 4 encroach both on first basic surface 11, second basic surface 12, and intersection line 13.

[0057] Likewise, at least a second bearing surface 12 can be made in a second component 20 with at least two basic surfaces 21, 22, secant on at least a second line of intersection 23 located in junction area 3, as seen in FIG. 5.

[0058] In the alternative where second component 20 is also provided with one or more second recesses 7, more particularly, at least one such second recess 7 is made on a second line of intersection 23.

[0059] More particularly, braze material 5 is chosen to be compatible both with the titanium alloy and the zirconia-based ceramic, when this is possible.

[0060] More particularly, first component 10 and second component 20 are ultrasonic cleaned prior to the brazing operation.

[0061] More particularly, the assembly is mechanically held tightly pressed in the vicinity of the junction area 3 during the brazing operation.

[0062] More particularly, a brazing paste is chosen as braze material 5, which is inserted under pressure at least inside each first recess 4, and/or respectively in each second recess 7 (where appropriate), set back from first surface 1 and/or respectively from second surface 2.

[0063] More particularly, as seen in FIG. 13, at least a first recess 4 is made with a neck 6 in proximity to first surface 1, wherein the cross-section of neck 6 is smaller than the cross-section of bottom 8 of first recess 4 opposite first surface 1, to form a mechanical key holding second component 20 to first component 10 after the brazing operation. More particularly, each first recess 4 is made with such a neck 6 in proximity to first surface 1, wherein the cross-section of neck 6 is smaller than the cross-section of bottom 8 of first recess 4 opposite first surface 1, to form a mechanical key holding second component 20 to first component 10 after the brazing operation.

[0064] In a variant, a single direction of insertion DI of second component 20 is determined for its alignment with first component 10, and at least a first recess 4 is made oblique or perpendicular to direction of insertion DI. More particularly still, each first recess 4 is made oblique or perpendicular to direction of insertion DI.

[0065] In another variant, a single direction of insertion DI of second component 20 is determined for its alignment with first component 10 and at least a first recess 4 is made in direction of insertion DI.

[0066] More particularly, a single direction of insertion DI of second component 20 is determined for its alignment with first component 10, and first surface 1 and second surface 2 are made with a radial clearance JR between them, in the free state before the deposition of braze material 5; said radial clearance JR is comprised between 0.010 mm and 0.040 mm at the radius, perpendicularly to direction of insertion DI. More particularly still, first surface 1 and second surface 2 are made with a radial clearance JR between them, in the free state before the deposition of braze material 5; said radial clearance JR is comprised between 0.015 mm and 0.025 mm at the radius, perpendicularly to direction of insertion DI.

[0067] More particularly, braze material 5 is inserted in each first recess 4 by means of a syringe.

[0068] More particularly, a braze material suitable for brazing tungsten carbide on steel is chosen as braze material 5.

[0069] More particularly, braze material 5 is chosen to include copper, manganese and nickel, and to be cadmium free, with extra-fine grain size, and to include a binder for brazing in a controlled atmosphere furnace at a temperature comprised between 1000 C. and 1100 C.

[0070] More particularly, controlled atmosphere heating is carried out for the brazing operation in an argon controlled atmosphere furnace comprising a belt with a speed into the furnace comprised between 0.15 m/mn and 0.25 m/mn.

[0071] More particularly, after the brazing operation, a first cooling operation is carried out on a belt with a belt speed of between 0.05 m/mm and 0.15 m/mm.

[0072] More particularly, the brazing and/or first cooling is carried out with a solid tool mechanically holding the assembly, and/or with a weight at least equal to that of the assembly placed and held on the assembly, to slow down the cooling of the assembly after the brazing operation.

[0073] More particularly, after brazing, the assembly is placed on a graphite support for rapid cooling without thermal shock.

[0074] More particularly, after brazing and/or the first cooling operation, the assembly is placed on a graphite support for rapid cooling without thermal shock.

[0075] More particularly, braze material 5 is deposited on first surface 1 and/or respectively on second surface 2, in a wave pattern 8, as seen in FIG. 10.

[0076] More particularly, at least a first recess 4 is made during the fabrication of first ceramic component 10, in particular this first recess 4 is made in the mould.

[0077] More particularly, at least one first recess 4 is completely machined, or finish-machined using a laser.

[0078] More particularly, at least one first recess 4 is completely machined or finish-machined mechanically using a tool or grinding wheel.

[0079] More particularly, grade 5 titanium is chosen as the titanium alloy. This grade 5 titanium includes, in % according to ASTM F136, from 0.00 to 0.08 C, from 0.0 to 0.3 Fe, from 0.0000 to 0.0125 H, from 0.00 to 0.05 N, from 0.0 to 0.2 O, from 5.50 to 6.75 Al, from 3.5 to 4.5 V, from 0.0 to 0.1 OE (other elements, each), from 0.0 to 0.4 TO (total other elements), and the remainder of Ti.

[0080] More particularly, the zirconia-based ceramic is chosen to include:

[0081] at least one stabilizer chosen from the group of oxides comprising yttrium oxide, magnesium oxide, and calcium oxide, alone or in combination;

[0082] at least one element intended to create a vitreous phase, and chosen from the group comprising silicon oxide, aluminium oxide, lithium oxide and yttrium oxide, alone or in combination;

[0083] an oxide powder used as pigment;

[0084] and a zirconia powder forming the remainder to 100% by weight.

[0085] More particularly, the zirconia-based ceramic is chosen to contain: [0086] 3 to 20% by weight of at least one stabilizer chosen from the group of oxides comprising yttrium oxide, magnesium oxide and calcium oxide, alone or in combination; [0087] 0.1 to 5% by weight of at least one element intended to create a vitreous phase, and chosen from the group comprising silicon oxide, aluminium oxide, lithium oxide and yttrium oxide, alone or in combination; [0088] 1 to 10% by weight of an oxide powder used as pigment; [0089] and a zirconia powder forming the remainder to 100% by weight.

[0090] The invention is more particularly illustrated with the brazed assembly of titanium alloy rings, in particular grade 5 titanium, on zirconia-based ceramic watch case middles. Trials show that an important parameter is the clearance, before brazing, between the case middle and the ring, which is necessary to allow proper thermal expansion, without undesired deformation. In particular, for a case middle with an assembly shoulder of around 37 mm, the clearance is advantageously comprised between 0.01 and 0.04 mm, and preferably close to 0.02 mm at the radius, between the case middle and the ring. Naturally, this low clearance value requires reduced machining tolerances, synonymous with cost.

[0091] It is possible to make undercut recesses with a laser. The object of these undercut recesses 4 is to create areas of mechanical adhesion, which reinforce the braze. Undercut recesses 4 may be located only in certain areas, for example in proximity to the horns of the case middle as seen in FIG. 8.

[0092] Brazing is correctly implemented with a CF CuMn3 braze material and with an argon controlled atmosphere furnace.

[0093] Good brazing conditions are as follows: [0094] speed into the furnace: 20 cm/min (desired speed); [0095] cooling speed: 10 cm/min (desired speed); [0096] brazing under argon atmosphere; [0097] furnace temperature: desired temperature of 1050 C.

[0098] The operating protocol includes all the steps performed to obtain the final product.

[0099] The braze material is deposited on case middle 10 based on the location of ring 20, and to the walls, and inside the previously made recesses 4. Further, it is advantageously deposited in the form of waves 8, as seen in FIG. 10.

[0100] Ring 20 is then positioned on the braze material.

[0101] When entering the furnace, to avoid ring 20 moving during thermal expansion, it is advantageous to place a weight on the ring, for example a weight equivalent to that of case middle 10. This weight also stabilises the assembly as the belt moves into the furnace. And especially, the presence of this weight allows the components to cool more slowly, especially the titanium ring. This subjects the assembly to less stress by limiting the effects of thermal expansion coefficients. It is observed, also, that the placing such a weight on the grade 5 titanium ring during cooling gives the ring some protection against oxidation.

[0102] On leaving the furnace, the brazed components are advantageously placed on a graphite stand to avoid thermal shock, and an additional weight, which is also of the order of magnitude of the weight of the case middle, is used to hold the ring securely in the bottom of the case middle during this more rapid cooling operation.

[0103] The presence of such undercut recesses is essential to ensure the adherence of the assembly, since, otherwise, the braze adheres to the titanium but does not properly adhere to the ceramic. Without the anchoring function performed by the weight of braze material 5 inside recesses 4, the ring would rise up as the components cooled, because of the difference in cooling speed of the two materials. This confirms that sufficiently slow cooling must be maintained to reduce to a maximum the stresses imparted by thermal expansion. It is also noted that the ring also tends to rise up because of the braze material which forms a thin interface layer between the titanium and the zirconia-based ceramic.

[0104] As a result of the undercut recesses 4, the undercuts serve as a mechanical anchor for the ring, since the braze material creates a metal support which holds the two components together.

[0105] Brazing grade 5 titanium rings on ceramic case middles is thus possible and gives good results in removal resistance tests.

[0106] The improvement of the method also involves optimising the sizing of the components, and in particular a reduction in the cross-section of the titanium rings, with a cross-section on the order of 0.75 to 1.00 mm.

[0107] The invention also concerns a watch 1000 including at least one structural and/or external element 100 made by the method according to the invention.

[0108] In short, the invention provides a durable, high quality assembly between grade 5 titanium components and zirconia-based ceramic components, with a method for controlled atmosphere brazing. It differs from other techniques in that material is added in the form of a brazing paste in the assembly step. Further, the invention ensures better mechanical and thermal properties for the assembly compared to usual technologies.

[0109] In the method, the brazing paste melts with the grade 5 titanium, which makes it possible to form a metal extension of the titanium component, but it does not react with the ceramic. Thus, all the mechanical and thermal resistance properties are defined by the braze, and by the quality of the anchoring thereof inside the recesses made in the ceramic component.