Active transition liquid phase diffusion welding technique of metal-matrix composite material

Abstract

The invention discloses an activity transition liquid phase diffusion welding technique for a metallic matrix composite material (MMC), comprising: firstly, presetting an active interlayer provided with following alloy family composition characteristics among metallic matrix composite materials to be welded, the active interlayer contains both melting point depressant elements capable of reacting with the metal base and active elements reacting with ceramic intensify phase; the active elements are elements which can react with the ceramic intensity phase in the composite material rather than elements which can react with the metallic matrix or metallic matrix surface oxide film; secondly, pressurizing onto the welding surface; heating with a temperature lower than the melting point of the active interlayer to ensure obtaining liquid phase by using eutectic reaction; performing thermal insulation for certain time; and completing welding. The invented technique can improve humectation and coherence between composite material welding area 'intensify phase / metal' week boundaries. In addition, the invented technique can be used broadly in welding process between heterogeneous materials such as between ceramic / metal, ceramic / MMC, metal / hard metal, etc.

Description

technical field [0001] The invention belongs to the field of welding, and in particular relates to an active transition liquid phase diffusion welding process for metal matrix composite materials. Background technique [0002] Compared with single metals, the outstanding advantages of metal matrix composites (Metal Matrix Composite, MMC) are in three aspects: high specific strength (light weight and high strength), excellent heat resistance and wear resistance. Since the 1990s, transitional liquid phase bonding (TLP: Transient Liquid Phase bonding, hereinafter referred to as "liquid phase bonding or TLP") of metal matrix composites has been a research hotspot. This is because, compared with other various welding methods, liquid phase diffusion welding (TLP) has the following significant advantages: [0003] (1) Compared with the fusion welding process (including arc welding, laser welding and electron beam welding), the embrittlement reaction of the "ceramic reinforcement p...

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Problems solved by technology

[0004] However, liquid phase diffusion welding of MMC also has two significant shortcomings: one is the particle segregation of the ceramic reinforcement phase in the center of the weld (Particulate segregation); the other is the "ceramic reinforcement phase / metal matrix" in the welding zone The bonding of the interface is weakened, and a large number of "ceramic reinforcement phase / metal matrix" weak interfaces appear

[0007] (1) The wettability of the ceramic reinforcement phase / metal interface in the joint is poor, so the interface compactness and bonding will inevitably deteriorate

[0008] (2) The secondary weak interface will not only cause interface debonding (direct impact on performance), but also lose the dislocation strengthening effect of interfacial thermal mismatch on the matrix near the interface (indirect impact on performance)

[0009] (3) Even if the uniformity of ceramic particle distribution can be achieved, the performance of the joint will still be lower than that of the composite base material due to the poor bonding of the ceramic reinforcement / metal interface

[0010] (4) The larger the volume fraction of the ceramic reinforcement phase, the worse the performance of the welded joint

[0011] It can be seen that the weakening of the ceramic reinforcement / metal secondary interface in the welding zone will seriously damage the performance of the joint, and the improvement of its bonding performance is an important issue to be solved urgently

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