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Al2O3-Cu/25W5Cr and Al2O3-Cu/35W5Cr composites were fabricated by vacuum hot-pressing sintering and internal oxidation process. The electrical conductivity, relative density and Brinell hardness were measured. The effects of the nano-Al2O3 and tungsten on the Al2O3-Cu/(W, Cr) composites hot deformation were investigated through the isothermal compression tests using the Gleeble-1500D thermo-mechanical simulator ranging from 650 degrees C to 950 degrees C and 0.001-10 s(-1) strain rate. The deformed microstructure was characterized and analyzed by optical and transmission electron microscopy. The interaction of work hardening, dynamic recovery and dynamic recrystallization was illustrated. It is demonstrated that Cr particles were extruded into strips; W particles underwent a slight deformation during the hot compression. Besides, the higher tungsten content composite had higher flow stress. Nano-Al2O3 particles pinned dislocations and inhibited the dynamic recovery and dynamic recrystallization. In addition, it is still in the stage of sub-crystals formation at 850 degrees C, 0.01 s(-1). Consequently, the Al2O3-Cu/35W5Cr composite has typical dynamic recovery characteristic. Hence, Al2O3-Cu/(W, Cr) composites demonstrate outstanding high temperature performance.
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