高Al新型Co-Al-W基高温合金热处理过程中的微观组织演变  

Microstructure evolution of Al rich Co-Al-W base superalloy during heat treatment

作　　者：陈艳辉[1] 龙海波[1] 毛圣成[1] 薛飞[2] 

机构地区：[1]北京工业大学固体微结构与性能研究所,北京100124 [2]中航工业北京航空材料研究院,北京100095

出　　处：《金属热处理》2016年第7期1-7,共7页Heat Treatment of Metals

基　　金：国家自然科学基金(50771012;11404014);北京工业大学开放课题(BJUT-GTS-200901)

摘　　要：利用电子显微技术研究了Co-12Al-10W三元高温合金在热处理过程中的微观组织转变过程。结果表明,铸态合金的显微组织存在初生Co Al相。经过1300℃×8 h固溶处理后,初生Co Al相完全固溶,并析出μ相。随后在900℃时效处理过程中,γ和γ'相两相共格结构在50 h后出现,γ'相的尺寸随时间的延长不断增大。在时效处理初期,析出相主要为μ相;随着时效时间的延长,部分μ相边缘出现了DO19相;而时效时间进一步延长至600 h后,大量的μ相边缘出现了DO19相和B2相,同时在晶内出现了大量的针状B2相。电子衍射谱的分析表明,μ相、DO19相、B2相和γ'相之间存在着特定的取向关系为[111]_(B2)//[110]_(γ'),(011)_(B2)//(111)_(γ'),[001]_μ//[110]_(B2)//[001]_(DO19),(112)_(B2)//(100)_μ//(100)_(DO19),(110)_(B2)//(027)_μ//(010)_(DO19)。这些特殊的取向关系归结于析出相之间的结构关联性,而相转变则由W元素在时效处理过程中的扩散作用造成。Microstructure evolution and phase transformation of Co-12Al-10 W superalloy during heat treatment were investigated by means of electric microscopy. The results show that primary Co Al phase appeares in as-cast alloy,and it is solid solved completely after solid solution at 1300 ℃ for 8 h with precipitation of μ phase. The γ / γ＇ matrix appeares after aging at 900 ℃ for 50 h and the main secondary phase is μphase in the early stage aged alloys. Small amount of coexisting cases including DO19,B2 and μ phases begin to appeare in prolonged aging alloys while it increases quickly in alloys after aging treatment for 600 h. A large quantity of acicular B2 phase precipitates in alloys aged for600 h in the same time. Diffraction patterns indicate a special orientation relation between base and precipitates as follows： [111]_（B2）//[110]_（γ＇）,（011）_（B2）//（111）_（γ＇）,[001]_μ//[110]_（B2）//[001]_（DO19）,（112）_（B2）//（100）_μ//（100）_（DO19）,（110）_（B2）//（027）_μ//（010）_（DO19）. The special relationship can be attribute to a related structure among them. The phase transformation can be attribute to the diffusion of element of tungsten during aging treatment.

关 键 词：钴基高温合金 析出相 相变 微结构 

分 类 号：TB31[一般工业技术—材料科学与工程] TG142.33[金属学及工艺—金属材料]