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SiC particle reinforced aluminum matrix composites have high specific strength and specific modulus, good wear resistance, etc., but the elongation was significantly lower than the matrix alloy and SiC particles in the matrix alloy uniformity is not ideal. Its plastic deformation, not only can improve the density of the composite material, but also can improve the uniformity of the distribution of the SiC particles, thereby increasing the strength of the composite material to improve its ductility and toughness. Above more coverage, but reported no research work on the movement and distribution characteristics of the different stress-strain state of SiC particles. In this paper, the laboratory's own crucible mobile spray deposition patented technology and powder metallurgy technology to prepare 7090Al/SiCp (SiCp volume fraction of 15%) aluminum matrix composite billets were taken hot extrusion (three-dimensional stress), etc. ECAP (pure shear stress) and wedge suppression technology (one-way compressive stress) and the plastic deformation of composite materials, spray deposition billets densification behavior during the plastic deformation of SiC particles broken, sports and redistribution induced by the following conclusions: (1) the spray deposition billet process, SiC particles adhered to the surface of the alloy droplets, resulting in more of the SiC particles in the alloy droplet surface, less internal SiC particles The lamellar distribution characteristics. Three compressional deformation under stress, this layered distribution characteristics difficult to eliminate the SiC particles in the extruded bar was banded streamline distribution, the cross section was \Extruded bar extrusion ratio increases, the SiC particles being more evenly distributed. (2) the use of P / M rule of law prepared by SiC particles uniformly distributed 7090Al/SiCp of composite blank, and hot extrusion experiments to study the distribution of SiC particles in the process of hot extrusion deformation, and spray deposited billet extruding the results were compared. Experimental results show that: the more uniform distribution of SiC particles in the original billets, extruded bar of SiC particles more uniform distribution. In the extrusion process, SiC particles in the matrix alloy Movement along the extrusion direction the directional distribution characteristics, this is determined by the stress characterized by hot extrusion deformation, but there is no formation of uneven distribution of the SiC particles strip organization; squeeze the pressure rod cross-section of SiC particles distributed more evenly, does not appear rings organization. Extrusion ratio of 11, extruded rods in the presence of a certain amount of alloy powder particles of the bonding interface, The extrusion ratio is not enough to completely metallurgically bonded to the alloy powder particles. Improve extrusion alloy particles binding interface than to 17 or more, the gradual elimination of metallurgical bonding. (3) squeeze to state 7090Al/SiCp composite material matrix alloy there are a large number of short rod the MgZn2 phase and round the CuAl 2 phase particles, MgZn 2 particles ca. 200nm, a diameter of approximately 60 nm, distributed in the grain interior; the CuAl 2 -phase spherical particles of different sizes, a large particle diameter of about 420nm, a small particle diameter of 40 ~ 60nm, mainly at the grain boundaries or near the grain boundary region. (4) 7090Al/SiCp extruded bar Solution and Aging system to determine the best solution temperature 475 ° C, the solution time 1h. After the solution treatment, the second phase particles MgZn2 and CuAl2 particles dissolved in the matrix alloy, the mechanical properties of the composite material rods: sB = 610MPa, delta = 2.0%; again after 120 ° C / 24h aging treatment, the composite material mechanical properties of bars: σb = 765MPa, δ = 1.5%. (5) studied channel angular pressing (ECAP) process on spray deposition 7090Al/SiCp composite bar organizations and performance, the results show that: ECAP temperature; Deformation Behavior of SiC particles in the ECAP the shear force is broken, empty broken SiC particles at 300 ℃ hard matrix alloy filler; extrusion temperature is increased to above 350 ℃, the gap between the broken SiC particles gradually filled substrate, the adhesive can be within a certain range with the flow of the matrix alloy, significantly improved uniformity. In this study, the best ECAP temperature to 400 ° C. (6) processing path A, BC, C, 400 ° C under to 7090Al/SiCp composite second-class multi-channel ECAP. The results show that the excellent mechanical properties when the extrusion path Bc After 4 passes after deformation, the grains are equiaxed grain, the grain size as 400nm; peak aging treatment, the tensile strength of the bar and yield the strength of 770MPa and 575MPa, modulus of elasticity 106.6GPa, an elongation of 7.4%; SiC particle size is significantly refined, broken by the initial state of about 10μm to about 2μm. (7) Based on the blank multi-pass deformation accumulated large deformation thinking, large-size spray deposition 7090Al/SiCp composite billets (510mm x 337mm x 200mm) wedge pressing the deformation process of SiC particles distribution law and holes deformation behavior. The results showed that, in the process of wedge pressure, the blank localized plastic deformation occurs, so that the porosity in the spray deposited billet shear deformation occurs, is closed, and the final densification of the preform; SiC particles in the pressing force occurs under the action of the rotation, so that The the SiC particles deposited billets disorder distribution to the orderly distribution of the long axis perpendicular to the direction of pressing, but the crushing effect is not obvious.
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