| Spray deposited MMCs reinforced with particle present many advantages such as uniformly distributed reinforcement particles, less interface reaction, rapid solidification rate in the billet. However, the billets produced by spray deposition have the disadvantages of definite porosity ratio, the non-metallurgical bond deposition interface. Therefore, for the achivement of high performance , further densifing process of the billets is required. Especially those for the addition of ceramic reinforcement particles, the billets have a lower workability. Although the workability of billets can be improved by extrusion, the microstructure with "tree ring" is obvious,and the dimension of material section is limited . The compressive deformation behaviour and the behaviour of rupture of co-sprayed 7075/ SiCp during compressive deformation were investigated. The method technology of forging that meet particle reinforced MMCs were explored in this paper in order to offer the theory foundation for the forging deformation of large dimension MMCs .The main research content and conclusion are shown as follows: (1) The thermal compression deformation behaviour of 7075/ SiCp composites by spray deposition was studied. The deformation behaviour of 7075/ SiCp composites by spray deposition was studied at Gleeble-1500 thermal –mechanical simulator. The compression workability is dominantly influenced by the technical parameters,such as deformation temperature ,strain rate,lubricative condition. The deposition shows good workability at the condition of 420℃ and appropriate lubrication with strain rate 0.001s-1.Because of the existence of pore, the softening rate of the billet become low with the increment of strain. Owing to the function of SiC particle of the billet, the deposite of composite exhibits high deformation stress than the 7075 alloy, the lower the temperature ,the higher the strain rate,the more increasement of deformation stress. The compression flow rule of the spray-deposited 7075/SiCp was studied at YJ32-100A type hydraulic pressure machine,at different technics conditions such as different temperature ,lubrication . During compression,the deposit followed quality invariability principle,and one portion of compression strain was used to deform the material at circumference and radial direction , while the other employed the material's volume contract and increment of the density.The radial direction strain were lower than that of the condense materials. While the higher the friction coefficient, the higher the deformation degree and the initial ratio of height to diameter ,the more obvious the barelling. When the deform temperature increased , with variety of fracture strain trace positions,the deformation safety region was enlarged at first and then decreased, and the maximum deformation safety region was obtained at 420℃. With the increasement of material's density ,the fracture strain trace position ascended and deformation safety region was enlarged. At the initial stages of compression, the increased amplitude of density was large,when the compressing degree reached 40%, the density was increased from 82.9% to 98%. And with the further compression, the velocity of condense decreased , when the compressing reached 80%, the density was only increased to 99.7%. After hot compressing deformation,most of the pore in the billet was disappeared and interface of deposition was obviously compact.But the linear distribution of SiC was still exited. (2) The investigation on the forging technique of the 7075/SiCp composites was carried out. When the direction of forging upright the surface of deposition, the workability of material was fine. By contrast, the 7075/SiCp composites easily ruptured along the surface of deposition, when the direction of forging paralled with the interface of deposition. After die pressing in 480~620 ℃ , the workability improved because contour forging can improve the bond of the interface in the deposite. The density was increased with increasing temperature of mould pressing. But thick phase was precipitated when temperature exceed 560 ℃ . When the mould pressing deposite packed with stainless steel was forged at 420 ℃ , the densification figuration workability of the billet improved markedly and the pore and interface eliminated effectively. (3) The investigation on the heat treatment and property of the as-processed 7075/SiCp composite was executed. The forged 7075/SiCp composites were solutionized at 450 ℃ for 2h, then quenched with water and age at 25 ℃ for 120h and 120 ℃ for 20h. The 7075/SiCp composites show good combination property, σ b= 570MPa,σs=490 MPa,δ=2%.
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