(北京航空材料研究院 先進(jìn)高溫結(jié)構(gòu)材料國防科技重點(diǎn)實(shí)驗室，北京100095)
摘 要: 對單晶高溫合金DD6進(jìn)行表面吹砂處理，然后在1 100~1 250 ℃加熱4 h，研究其鑄態(tài)與標(biāo)準(zhǔn)熱處理狀態(tài)的表面再結(jié)晶行為。結(jié)果表明：當(dāng)加熱溫度為1 200 ℃時，鑄態(tài)合金出現(xiàn)等軸再結(jié)晶晶粒；而加熱溫度為1 150 ℃時，熱處理態(tài)合金出現(xiàn)等軸再結(jié)晶晶粒，鑄態(tài)與熱處理態(tài)合金的再結(jié)晶是由胞狀再結(jié)晶晶粒和等軸再結(jié)晶晶粒組成的；隨著加熱溫度的升高，等軸再結(jié)晶晶粒逐漸長大，胞狀再結(jié)晶晶粒逐漸減少，胞狀再結(jié)晶內(nèi)部粗大的g ¢相由長條狀向顆粒狀轉(zhuǎn)變。由于鑄態(tài)合金含有一定數(shù)量的粗大g ¢相以及g+g ¢共晶組織，在相同的條件下，鑄態(tài)合金的再結(jié)晶傾向小于熱處理態(tài)合金的。
關(guān)鍵字: 單晶高溫合金；DD6合金；等軸再結(jié)晶；胞狀再結(jié)晶；合金狀態(tài)
single crystal superalloy DD6
（National Key Laboratory of Science and Technology on Advanced High Temperature Structural Materials,
Beijing Institute of Aeronautical Materials, Beijing 100095, China）
Abstract:The samples of single crystal superalloy DD6 were grit blasted and heat treated in the temperature range of 1 100−1 250 ℃ for 4 h in vacuum atmosphere, then the recrystallizations of as-cast and standard heat treatment DD6 alloys were investigated, respectively. The results show that the equiaxed recrystallization grains nucleate in as-cast samples heat treated at 1 200 ℃, while the equiaxed recrystallization grains occur in the standard heat treatment samples heat treated at 1 150 ℃. The recrystallization region consists of cellular recrystallization and equiaxed recrystallization grains at different states. With the improvement of the heating temperature, the size of cellular recrystallization decreases, while the size of equiaxed recrystallization grains increases, and the coarse g ¢ phase in the cellular recrystallization changes from lamellar to equiaxial. By comparing with the as-cast samples, the standard heat treatment samples tend to recrystallization at the same heating temperature due to the absence of coarse g ¢ and g+g ¢ eutectic.
Key words: single crystal superalloy; DD6 alloy; equiaxed recrystallization(ERX); cellular recrystallization(CRX); alloy states
