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TiC-CoCrFeNi composite was fabricated by mechanical alloying and consequently vacuum hot pressing sintering, and the effects of milling time on the microstructure and mechanical properties of the composite was investigated. The results show that a single-phase solid solution with fcc structure is obtained after milled for 10h of Co, Cr, Fe and Ni powders. TiC and Cr7C3 structured carbides are formed and dispersed in the CoCrFeNi solid solution after hot pressing sintered at 1200℃ for 1h. Milling time has a significant effect on the size and amount of TiC and Cr7C3 structured carbides, which can affect the mechanical properties of the composite. When the milling time reaches 10h, the hardness and yield strength of the composite reach the maximum values of 671HV and 1440MPa, respectively, which is probably attributed to the dramatically increasing of nano-sized TiC in sintered bodies.

The CrCuFeMnNi high entropy alloy (HEA) powder was synthesized by mechanical alloying. The effects of milling time and subsequent annealing on the structure evolution, thermostability and magnetic property were investigated. After 50 h of milling, the CrCuFeMnNi HEA powder consisted of a major FCC phase and a small amount of BCC phase. The crystallite size and strain lattice of 50 h-ball-milled CrCuFeMnNi HEA powder were 12 nm and 1.02%, respectively. The powder exhibited refined morphology and excellent chemical homogeneity. The supersaturated solid solution structure of the as-milled HEA powder transformed into FCC1, FCC2, a small amount of BCC and ρ phase in annealed state. Most of the BCC phase decomposed into FCC (mainly FCC2 phase) and ρ phases, and the dynamic phase transition was almost in equilibrium at 900 ∘ C. The saturated magnetization and coercivity force of the 50 h-ball-milled CrCuFeMnNi HEA powder were respectively 16.1 emu/g and 56.2 Oe. Phase transition of supersaturated solid solution structure of the as-milled CrCuFeMnNi HEA powder occurred at annealed condition of 700∼900∘C. FCC phase completely transformed into FCC1 and FCC2 phases. However, most of the BCC phase decomposed into FCC (mainly FCC2 phase) and ρ phase (Cr5Fe6Mn8), and the dynamic phase transition was almost in equilibrium at 900∘C. [ABSTRACT FROM AUTHOR]