Abstract: A method for fluxless brazing of unclad aluminum includes forming first and second components to be joined of unclad aluminum; etching selected surface areas of the components; depositing an elemental metal on the selected surface areas; abutting the first and second components along the etched surfaces forming a junction; applying an aluminum filler about the junction; and heating the components and filler and bonding the components and filler.

Abstract: An intermetallic bond between a ferrous metal and a non-ferrous metal wherein an intermetallic bond layer that is substantially free of graphic inclusions joins the two. The graphite is effectively eliminated from the bond layer by either removing it from the ferrous metal or by sealing it off from the bond layer. Graphite removal may be accomplished in a variety of ways, including electrochemical cleaning and laser surface treatment. Alternatively, the graphite may be prevented from incursing into the bond region by sealing it off with a layer of metal, such as a chromium plating, that prevents it from penetrating through the bond layer and into the non-ferrous metal.

Abstract: The invention is a method and resulting device which provides a strong bond between a silicon substrate and an oxide component mounted within a cavity in the substrate. A layer of titanium, for example, is deposited on the walls of the cavity, followed by deposition of a layer of aluminum. The structure is preferably annealed to form titanium silicide and titanium-aluminum interface layers. The component is then bonded to the aluminum layer.

Abstract: A method which utilizes flip chip technology to provide interconnection between printed circuit boards and integrated circuits is disclosed. The method involves metallization of the bond pad and multiple, novel bump compositions and coating compositions to provide an interconnection which is reliable and which withstands differences in the coefficient of thermal expansion between the silicon device and the bump material.

Abstract: A heat exchanger assembly includes at least one tube having an internal surface and an external surface, a composition cladding having at least lithium and magnesium applied to either one of the internal surface and external surface of the tube, and at least one component disposed adjacent the composition cladding, whereby the tube and component are joined together during a controlled atmosphere brazing process.

Abstract: A method of manufacturing an ultrasonic generator adapted to ultrasonic sterilizers, for minimizing the heat input of a magnetostrictive element, comprises the steps of: forming, on a wave guide, melting layers constructed of joining materials such as Al--Si alloy and Sn--Ag alloy which melt within a temperature range of 575.about.590.degree. C. and 230.about.250.degree. C., respectively, and have tensile strength of 17.about.25 kg/mm.sup.2 and 10.about.15 kg/mm.sup.2, respectively; and joining the wave guide with the magnetostrictive element.

Abstract: The object of the invention consists of a process through which containing metal structures are built and shaped, in one case using steel sheets pre-protected by paints, and made to be electrically conductive by adding aluminium powder, or other equivalent conductive metals having a fusion temperature which is equivalent to the one fusing the sheets to be welded, and whose boiling temperature is higher than their fusion one; in a second case using sheets pre-protected by a thin layer of zinc plating followed by an external film of acrylic resin; it also consists in resorting to the aid of anthropomorphic welding robots, at the end of whose mobile arm is placed the laser beam out put unit connected to the laser source by an optical fibre cable, and also in the fact that the welding is carried out on the internal not visible sides of the containing structures that are being built.

Abstract: A method by which semiconductor wafers (10, 12) can be solder bonded to form a semiconductor device, such as a sensor with a micromachined structure (14). The method entails forming a solderable ring (18) on the mating surface of a device wafer (10), such that the solderable ring (18) circumscribes the micromachine (14) on the wafer (10). A solderable layer (20, 26, 28) is formed on a capping wafer (12), such that at least the mating surface (24) of the capping wafer (12) is entirely covered by the solderable layer (20, 26, 28). The solderable layer (20, 26, 28) can be formed by etching the mating surface (24) of the capping wafer (12) to form a recess (16) circumscribed by the mating surface (24), and then forming the solderable layer (26) to cover the mating surface (24) and the recess (16) of the capping wafer (12).

Abstract: The invention relates to a method for joining coated metallic conductors and the application of the method to production of very high density microjoints as well as to the fabrication of macrojoints. It is characteristic for the invention that the surfaces to be connected are coated with solder metal or solder alloy layers, one on the top of the other. The mating contact areas are heated for a short period of time over the temperature where the base coatings and the top coatings fuse transiently. It is essential that the base coating and the top coating cannot produce intermetallic compounds with each other and that the contact interface between them is as metallic as possible. This kind of contact can be obtained for example by chemical or electrochemical deposition. Moreover, when the topcoat is capable of protecting the base coating, for example bismuth, the joining can be performed under normal atmosphere and without any flux.

Abstract: The method provides a process for fabricating metal matrix composites. First the process coats the fibers with nickel by electrodeposition or gaseous deposition to form nickel-coated fibers. Over-plating the nickel-coated fibers with aluminum by either electrodeposition in a non-aqueous electrolyte or gaseous deposition forms aluminum-coated-nickel-coated fibers. Sintering this product under compression, perpendicular to the fiber's central axis, forms the final metal matrix composite. The metal matrix composite has a nickel-aluminum matrix, very few voids and extended unbroken lengths of fibers within the nickel-aluminum matrix.

Abstract: A method for bonding silicon-containing compositions to metal surfaces is disclosed wherein a coarse silicon-containing surface is arc-sprayed with a first adhesive layer, a second solderable layer, and a third solder layer, and the arc-sprayed surface is then soldered to the metal surface. The method is particularly useful for producing silicon-containing targets for cathode sputtering.

Abstract: The occurrence of partial chip detachment is reduced by improving wettability for increasing the bonding strength, and by enabling gradual melting of the solder. Solder material, electronic components, and electronic circuit boards with higher performance and higher reliability are offered. The surface of a solder core, lead-frame surface and electrode surface of electronic components, and copper (Cu) land surface of electronic circuit boards are coated with metal element, which is either indium (In) or bismuth (Bi).

Abstract: Copper-containing surfaces of substrates such as laminated electronic circuit boards are protected by organometallic coatings comprising organic compounds selected from the group consisting of benzimidazoles, alkylimidazoles, benzotriazozles and alkyltriazoles, substituted or unsubstituted, and metal particles of solder-wettable metals or metal solders. The metal particles can be thermally formed in situ from metallic compounds such as noble metal acetates, acetylacetonates and carbonates.

Abstract: A reworkable cold welded microelectronic multi-chip module contains cold welded microelectronic chips in which the chip's cold weld metal bonding pads (3) are constructed of a metal having one hardness and the corresponding cold weld metal bonding pads of the multi-chip module's substrate (5) are of a different greater hardness, which, despite the difference in hardness, cold weld to one another. Two forms of Indium preferably serve as the metals. If for any reason the chip must be removed from the module, it is found that the cold weld breaks at a predictable location. A new microelectronic chip may thereby be cold welded to the module substrate as a replacement. New rework and testing procedures are thereby made possible.

Abstract: The invention relates to a solder bump for flip-chip assembly and consist of a core containing a high proportion of a soft and electrically well conducting metal, particularly gold, and a diffusion barrier layer deposited on the solder bump core. As is known, the diffusion barrier layer functions to prevent intermetallic compounds between the gold of the solder bump core and the solder material, especially tin-lead solder material, which would otherwise reduce the mechanical stability of the solder connection. A pre-treatment with a cleaning solvent or in a nucleation bath has hitherto been necessary. to provide a good bond between the diffusion barrier layer, usually nickel, and the solder bump core. With the invention, this pretreatment process step is no longer necessary, since small amounts of a material are added to the solder bump core which acts as a nucleation material for the diffusion barrier layer.

Abstract: In a process for applying a metallic adhesion layer for thermally sprayed ceramic thermal barrier coatings to metallic components, the surface which is to be coated being cleaned in a first process step, so that the metallic surface is free of grease and oxide, a binder is applied to the metallic surface of the base material in a second process step. Metallic adhesive powder is applied uniformly to the binder in a third process step and solder powder, which has a smaller particle size than the adhesive powder, is applied uniformly to the binder in a fourth process step. After drying the binder, a heat treatment is carried out for the purpose of soldering. The adhesion layers produced in this way are rough and provide a considerable positive lock for the ceramic thermal barrier coatings which are to be sprayed thereon.

Abstract: In a method for fastening electronic components on a substrate by means of pressure sintering, which includes providing a layer of sinterable metal powder on a surface of one component, assembling the components engaging the layer and then, while exerting a pressure on the components, applying heat to sinter the layer of material, an improvement comprises forming the layer of sinterable metal powder by vaporizing a metal and condensing the metal as a nanocrystalline metal powder on the surface. Preferably, the metal powder is silver and is applied in a precipitation chamber.

Abstract: Described is a hot pressed and sintered sputtering target assembly formed of hot pressed and sintered metal powder diffusion bonded together and to a backing plate by use of an intermediate adhesion layer of titanium or titanium alloy.

Abstract: A process is provided which enables electrical connection to be formed between gold and aluminum wires and copper interconnects. Conventional techniques for wire bonding are ineffective for bonding gold wires or aluminum wires to copper pads or copper interconnects. A process is provided to modify the copper pads so that conventional wire bonding techniques can be employed. In the process of the present invention an aluminum pad is formed over the copper interconnects. The metal wire is then bonded to the aluminum pad using conventional wire bonding techniques. No new hardware and/or technology is required for the metal wire bonding. No new technology is required to integrate the process of the invention into existing IC fabrication processes.

Abstract: A soldering method for soldering electronic components onto a copper (Cu) substrate using a tin (Sn) solder alloy. The method comprises in pretreating the Cu substrate by depositing a thin layer of zinc (Zn) before the deposition of the Sn solder alloy. This method greatly enhances the mechanical and electrical properties of the solder alloy, allowing the use of lead (Pb) free alloys such as tin-bismuth (Sn--Bi).

Abstract: A process for manufacturing a structural element capable of carrying high thermal loads, such as a heat shield for fusion reactors. The structural element comprises components of high heat-resistant material (such as graphite) joined to metallic components. A metallic, ductile intermediate layer is applied to the components of high heat-resistant material and then, the components of high heat-resistant material and metallic components are joined by high-energy beam welding.

Abstract: A method of mass-producing reliable, optical isolators, which allows reliable soldering and metallization in large quantities. The method comprises forming grooves (2) wider than a cutting margin along predetermined cut lines for cutting out a plurality of optical devices on the surface of an optical material block (1), forming then an antireflection film and a metallized film (3), and cutting the block along the grooves (2) ino optical elements (5).

Abstract: A method for preparing a Ni base superalloy inner wall surface of a body open end, such as an end of a turbomachinery blade, and an end plate, such as a blade tip cap, for brazing together at a rim of the end plate includes electrochemically removing oxides from the inner wall surface. The end plate is prepared, at least at its rim, by first removing surface and subsurface oxides, for example by mechanical abrading or a combination of such abrading and acid cleaning. Then at least the rim is electroplated with Ni which is heated to diffuse the Ni into the rim substrate. This provides an improved combination of surfaces for brazing for example with a Ni base brazing alloy. After brazing the rim to the inner wall, there is provided an article with an improved relatively low oxide brazed joint, including less than about 20 volume % oxides, and a plate rim of substantially Ni along with elements diffused from the brazing alloy and the rim.

Abstract: A method of braze joining a copper member to a substrate of metal or ceramic material is disclosed according to which a diffusion barrier coating as defined is applied to the substrate alone, and a selected brazing alloy is interposed between copper member and substrate, followed by a two-step heating treatment. In the first step the assembly is heated at a temperature and for a time sufficient to melt the brazing alloy and cause a bond to form between the brazing alloy and the copper member and between the brazing alloy and the substrate. In the second step the temperature is raised and maintained in the range from about 600.degree. C. to about 950.degree. C. in a "solutionizing heat treatment" (as defined) for a time sufficient to allow the brazing alloy to form an "extended solid solution" (as defined) with copper in a controlled fashion to convert the bond to a strong joint which is resistant to thermal stress.

Abstract: A process for forming a single material from two layers of metal materials by heating and pressing the two metals together under pressure where a first metal has a relatively higher temperature of plastics formation state and the second metal has a relatively lower temperature of plastics formation state comprising the steps of cleaning the surface of the first and second metal, then electroplating a thin layer of the second metal onto the surface of the first metal, then heating the first metal and the thin layer of the second metal electroplated thereon to the temperature of plastics formation state in the second metal, and heating the second metal to the temperature of plastics formation state, and mechanically pressing the thin layer of the second metal on the first metal together with the second metal to form a single ductile material having two layers of said first and second metals.

Abstract: A method for bonding one body to another, such as a laser device to a submount, uses a metallic layer composed of a Group VB metal, such as niobium, sandwiched between a non-metallic layer and solder layer formed by an approximate Au-Sn eutectic layer. Advantageously the Group VB layer is formed at a submount temperature of less than approximately 201.degree. C., advantageously less than approximately 125.degree. C., and preferably less than approximately 101.degree. C.--advantageously to a thickness in the approximate range 0.05 .mu.m to 0.2 .mu.m, or even thinner if pinholes do not develop. The non-metallic layer is located on one of the bodies, and the other body has a metallic coating advantageously capped with an Au layer.

Abstract: Disclosed herein is a method for electrically conductive metal-to-metal bonding. The method for bonding flat metal surfaces comprises the steps of depositing a thin layer of titanium on a first surface of a first metal surface, placing the first surface of the first metal surface in contact with a first surface of a second metal surface in an inert ambiance, heating the inert ambiance to a temperature substantially below the melting point of the metal surfaces, and forming a titanium metal bond between the first metal surface and the second metal surface to provide a low resistive path between the first metal surface and the second metal surface.

Abstract: A method is provided for joining beryllium pieces which comprises: depositing aluminum alloy on at least one beryllium surface; contacting that beryllium surface with at least one other beryllium surface; and welding the aluminum alloy coated beryllium surfaces together. The aluminum alloy may be deposited on the beryllium using gas metal arc welding. The aluminum alloy coated beryllium surfaces may be subjected to elevated temperatures and pressures to reduce porosity before welding the pieces together. The aluminum alloy coated beryllium surfaces may be machined into a desired welding joint configuration before welding. The beryllium may be an alloy of beryllium or a beryllium compound. The aluminum alloy may comprise aluminum and silicon.

Abstract: An apparatus for coating and bonding parts in a vacuum includes a floating mount assembly holding one part and applying a bonding load to the parts. A pivoting mount assembly holds one part and is pivoted between a coating position and a bonding position. At least one coating source is provided for depositing a thin film of a metal onto a surface of each of the parts to improve the cold weld between the two parts. A restraining lever controls the application of the bonding load to the parts. The coating and bonding process occurs in a vacuum chamber with a single set-up.

Abstract: Microextruded tubes each having two side surfaces, front and trailing edge surfaces and two ends are provided for insertion into aligned slots in headers to complete a heat exchanger assembly. The tubes each include a first coating composition containing an adhesive binder vehicle, flux material and brazing alloy deposited on the side surfaces adjacent the ends of the tube. The first coating composition is structurally arranged and applied to engage the aligned slots in the headers upon the insertion of the ends of the tubes into the header. The side surfaces of the microextruded tube include a second surface coating containing an adhesive binder vehicle, flux material, zinc and silicon extending the length of side tube between the deposited first coatings. The front and trailing edge surfaces of the tube include a third surface coating composition containing adhesive binder vehicle, flux material and zinc. A method of manufacturing parallel flow-type heat exchangers is disclosed.

Abstract: A method for attaching a metal wheel disc to a wheel rim formed from a metal which is dissimilar to the wheel disc metal. A layer of metal which is compatible for welding to the metal forming the wheel disc is thermally sprayed onto an outboard portion of the wheel rim to form a weld anchor. The wheel disc is positioned adjacent to the sprayed metal layer and welded thereto. The wheel disc also can be cast or forged over the sprayed metal layer with the wheel disc bonding to the sprayed metal layer to form a secure air-tight seal between the wheel disc and the wheel rim. Alternately, a metal filler compatible with both the metals forming the wheel disc and wheel rim is thermally sprayed onto the wheel rim and the wheel disc brazed thereto.

Abstract: The invention is directed to a method and a product produced by the method where in there is created a multi-metal composite object that takes on the configuration of a shaft which would include in combination an outer annular element having an outer cylindrical surface and an inner frusto conical annular metal element of a dissimilar metal. The inner frusto conical annular metal element of dissimilar metal includes an inner mating frusto conical surface bonded to a mating outer frusto conical surface of another metal element to thereby provide a multi-metal element composite shaft. The composite object in a preferred embodiment of the invention takes the form of a multi-metal element composite gear, web and shaft that includes a steel outer annular gear toothed element, an inner aluminum element and a titanium element that provides a gear web and shaft.

Abstract: Ion vapor deposition of aluminum is used to coat aluminum-beryllium alloy parts prior to fluxless vacuum brazing.

Abstract: An improved method of brazing of two unclad aluminum shapes, particularly for automotive heat exchangers, which brazing joint does not leave a physically apparent layer of brazing material and which effects a stronger, sounder autogenous joint. A thin film of aluminum eutectic forming material (Si, Al-Si or Al-Zn) is deposited onto a zone of at least one of the shapes to be brazed or joined. The shapes are placed in joining relationship to form an assembly with a joint at the zone. The assembly is heated to a temperature to diffuse the eutectic forming material into the aluminum members to form a sacrificial bond between the shapes at the joining zone. It is desirable that at least one of the unclad aluminum shapes to be joined is extruded tubing having a precise diametrical configuration and said film is deposited as a physically vapor deposited layer in a thickness range of 1-50 microns.

Abstract: A method of bonding a light polarizer having a metal sheet 4, 4-1 affixed to an end face thereof to a securing metal layer 5 involves bonding the securing metal layer 6 to the metal sheet 4, 4-1 by means of welding, whereby not only the working efficiency may be enhanced, but also long-term reliability in bonding may be ensured.

Abstract: An essentially fluxless solder joining process comprises a solder coating to be applied to a surface under controlled pressure conditions enabling the volume and shape of the solder to be desirably controlled. Coatings produced by essentially fluxless processes enable joining processes to be carried out in an essentially fluxless manner with highly desirable processing flexibility.

Abstract: A vacuum package assembly (20) is prepared by self-welding the flanges (32 and 43) of two housings (28 and 36) together under an applied pressure, while the housings (28 and 36) and any enclosed structure or device are contained within an evacuated enclosure. The flanges (32 and 43) are preferably made of copper, with their respective self-welding members (34 and 46) specially prepared to enhance self-welding performance. The preferred treatment for the self-welding members (34 and 46) is to deposit a thin layer of nickel onto the self-welding members (34 and 46 ), deposit a thin layer of gold over the nickel, and heat the bonding member to elevated temperature to interdiffuse the gold into the self-welding member (34 and 46 ).

Abstract: A monolithic circuit, such as a piezoelectric device, semiconductor, or the like, may be fabricated by forming an operational metallization layer (12) on a substrate (10). A subsequent layer (40), such as a sealing ring pattern (42) may then be applied using a thin film deposition technique. A thin film material is applied through a mask assembly (28). The mask assembly (28) includes a mask material (30) that has been applied to a screen (24) and patterned as desired. The mask material (30) extends beyond the screen (24) so that only the mask material contacts the substrate (10) during thin film deposition. Preferably, the screen (24) is woven from individual wires (26) having circular cross-sectional shapes. The subsequent layer (40) is applied both through perforations (18) in the screen (24) and under the screen's wires (26).

Abstract: A method of affixing a passive dielectric component to a printed circuit board comprising the steps of forming a metallised area on the p.c.b. separate from the printed electrical circuitry, forming a like metallised area on the component, applying solder material to one of the metallised areas, placing the component on the metallised area on the board and reflowing the solder to create a metal-solder-metal bond between the component and the p.c.b. whereby the component is accurately aligned with respect to the printed electrical circuitry on the p.c.b.

Abstract: A hot diffusion welding method wherein a first part generally made from a material different from a second part and the second part made from copper alloy are united with an insert material interposed between the joint faces thereof under a heated and pressurized condition. The insert material at the joint between the first and second parts is copper plating formed on the joint face of the first part made from the different material, so that the thermal conductivity between the two parts is improved to perform smooth resistance heating. This enables continuous welding operation without polishing the conductive surfaces of a pair of electrodes in order to eliminate oxides therefrom.

Abstract: A joining method of an aluminum member to a dissimilar metal member excluding copper by brazing or soldering through the use of a brazing filler metal or a solder for aluminum member; in which a plating composed of a metal voluntarily selected from copper, aluminum, zinc, lead, silicon, cadmium, tin and an alloy having major component of two or more kinds of them, is previously applied on a surface of joined portion of the dissimilar metal member, the plated joined portion of the dissimilar metal member is dipped in a molten brazing filler metal or a molten solder and ultrasonic vibration is given to the joined portion to stick the brazing filler metal or the solder to the joined portion, and a brazing or a soldering is carried out thereafter.

Abstract: Potential difficulties with corrosion in hear exchangers utilizing aluminum fins are avoided by using fin and tube constructions made by a method which includes the steps of providing a flattened tube (50) of ferrous material (80) and having an exterior coating (82) predominantly of aluminum providing at least one serpentine fin (56) of aluminum (86) and clad with a predominantly aluminum braze cladding (88); assembling (102) the fin (56) to the flattened tube (50); applying (94), (100), (104), a brazing flux to at least one of the fin (56) and the tube (50); raising (106) the temperature of the assembly to a level sufficient to at least partially melt the braze cladding (88); and maintaining the temperature for a sufficient period of time to achieve a brazed joint (60) between the fin (56) and the tube (50) but a time insufficient to convert the coating (82) and the cladding (88) to ferrous-aluminum intermetallic compound or intermediate phase.

Abstract: Methods of bonding a titanium containing sputter target member to a heat conductive backing member, such as a copper backing plate, and bonded target/backing plate assemblies are disclosed. Due to the poor wettability of titanium based materials, a uniform, thin film of aluminum is coated thereover and acts as an anchor layer for application of tin and/or indium based solder layers thereover to securely solder bond the target and backing plate. The aluminum coating is sputter coated onto the target. Then, the coated target is heated in an oxygen containing atmosphere. The thus treated titanium target is then ready for conventional solder joining to a copper backing plate or the like by use of tin, lead, and/or indium based solder metals.

Abstract: A method of bonding together two dissimilar planar bodies, one of which is a semiconductor. A film of palladium is deposited on one of the bodies. The two bodies are pressed together with moderate force with the palladium in between. The palladium chemically reacts with the semiconductor and, at least in the case of GaAs, dissolves the surface oxide and forms a crystalline palladium/semiconductor product topotaxial with the semiconductor.

Abstract: A method of electrically connecting a tape automated bonding lead to an aluminum input/output pad of an integrated circuit includes sequentially sputtering an adhesive layer, a diffusion barrier layer and a gold layer on the input/output pad. The adhesive layer is a metallic film having good step coverage and adhesive properties to contact the pad. The diffusion barrier layer is formed atop the adhesive layer and is sandwiched by the gold layer. The method employs "bumpless" techniques and the bond lead is connected to the gold layer by applying a combination of pressure and vibrational energy.

Abstract: The present invention relates to a solid state assembly having a solid state device bonded to a terminal board of an insulating material having a plurality of metal terminal pads thereon and arranged in a pattern. A metal bump is on each of the terminal pads of the terminal plate with an amalgam layer covering at least a top of each bump. The solid state device has a plurality of metal terminal pads thereon. The solid state device is mounted on the terminal board with each of its terminal pads being seated on the amalgam of each bump on the terminal board. The assembly is formed by placing some amalgam on each of the bumps on the terminal plate. The solid state device is then mounted on the terminal plate and the amalgam is hardened, such as by heating at a low temperature, to bond the amalgam to the bumps and the solid state device terminal plates.

Abstract: A thermally and electrically conductive paste for making a detachable and compliant connection between two surfaces. The paste comprises an equilibrium mixture of an electrically conductive liquid metal and particulate solid constituents, wherein at the temperature of the paste during connection the proportions of liquid metal and particulate solid constituents remain between the ultimate liquidus and the ultimate solidus of the phase diagram of the mixture and the paste remains non-solidified. in cryogenic and low temperature environments the paste forms a hardened bond with a TCE matched to a contacted surface.

Abstract: A process for producing non-corrosive double-wall tubing in which an unbrazed, unsealed continuous double-wall tube of a given circumference is formed from a metal sheet composed of a first non-ferritic metal having a first defined region of exposed non-ferritic metal and a second region of a second metal in overlying relationship thereto, said exposed region having a width essentially equal to the circumference of the finished tube.

Abstract: A method of bonding a superconductive ribbon lead to a superconductive bonding pad connected to superconducting circuitry. The thin ribbon is first coated with a fresh layer of the same material from which it is made and then a very thin layer of a noble metal is applied over that fresh layer. The bonding pad is also prepared with a very thin layer of the noble metal. Those coated surfaces are placed in facing contact and ultrasonically bonded.

Abstract: A method for fabricating a titanium aluminide composite structure consisting of a filamentary material selected from the group consisting of silicon carbide, silicon carbide-coated boron, boron carbide-coated boron, titanium boride-coated silicon carbide and silicon-coated silicon carbide, embedded in an alpha-2 titanium aluminide metal matrix, which comprises the steps of providing a beta-stabilized Ti.sub.3 Al foil containing a sacrificial quantity of beta stabilizer element in excess of the desired quantity of beta stabilizer, fabricating a preform consisting of alternating layers of foil and a plurality of at least one of the aforementioned filamentary materials, and applying heat and pressure to consolidate the preform. In another embodiment of the invention, the beta-stabilized Ti.sub.3 Al foil is coated on at least one side with a thin layer of sacrificial beta stabilizer.