文档介绍：Trans. Nonferrous Met. Soc. China 24(2014) 25442553Effect of hot extrusion and heat treatment onmicrostructure of nickel-base superalloyChen-ze LIU1, Feng LIU1,2, Lan HUANG1, Liang JIANG1 1. State Key Laboratory of Powder Metallurgy, Central South University, Changsha 410083, China;2. School of Metallurgy and Environment, Central South University, Changsha 410083, ChinaReceived 23 July 2013; accepted 12 May 2014Abstract: Effects of hot extrusion (HEX) and heat treatment on prior particle boundary (PPB), MC carbides, γ′ precipitates and grainsize of nickel-base FGH96 superalloy were studied. The results show that PPB consists of large γ′, MC carbides enriched with Ti, Nband a modicum of oxides. Thereafter, it can efficaciously tune γ′ precipitate size from micrometer down to nanometer region andsimultaneously results in the annihilation of PPB by HEX process. The activation energy for grain growth of as-HEXed FGH96superalloy was measured to be kJ/mol, indicating that γ′ precipitate serves the critical role in inhibiting grain growth undersub-solvus heat treatment. Moreover, the results reveal that grain growth is primarily restrained by MC carbide in the case ofsuper-solvus words: nickel-base superalloy; carbide; prior particle boundary; hot extrusion; heat treatment1 IntroductionPowder metallurgy (P/M) Ni-base superalloys arewidely used in the aerocraft en