《金属基复合材料》第六章，复合材料的制备-new.ppt

Chapter 6, fabricated methods  of Metal Matrix Composites Metal matrix composite materials can be produced by many different techniques. The focus of the selection of suitable process engineering is the desired kind, quantity and distribution of the reinforcement components (particles and fibers), the matrix alloy and the application. By altering the manufacturing method, the processing and the finishing, as well as by the form of the reinforcement components it is possible to obtain different characteristic profiles, although the same composition and amounts of the components are involved. The production of a suitable precursor material, the processing to a construction unit or a semi-finished material (profile) and the finishing treatment must be separated. For cost effective reasons prototypes, with dimensions close to the final product, and reforming procedures are used, which can minimize the mechanical finishing of the construction units. 6.1 Classification of fabricated methods for MMCs according to the introducing mode of reinforcement: Ex-situ methods; In situ methods。 according to the matrix state during processing: Solid methods; Liquid methods; S-L phases methods。 In general the following product engineering types are possible:Melting metallurgical processes infiltration of short fiber-, particle- or hybrid preforms by squeeze casting, vacuum infiltration or pressure infiltration; reaction infiltration of fiber- or particle preforms ; processing of precursor material by stirring the particles in metallic melts, followed by sand casting, permanent mold casting or high pressure die casting ; Further processing of precursor material from the melting metallurgy by thixocasting or -forming, extrusion , forging, cold massive forming or super plastic forming; Joining and welding of semi-manufactured products; Finishing by machining techniques ; Combined deformation of metal wires (group superconductors). Powder metallurgical processes