Cr含量对一种单晶高温合金凝固行为的影响  

Effects of Cr content on solidification behavior of a single crystal superalloy

作　　者：史振学[1] 刘世忠[1] 王效光[1] 岳晓岱[1] 李嘉荣[1] 

机构地区：[1]北京航空材料研究院先进高温结构材料重点实验室,北京100095

出　　处：《兵器材料科学与工程》2016年第1期1-5,共5页Ordnance Material Science and Engineering

摘　　要：为获得Cr元素在新一代单晶高温合金中的作用,在真空定向凝固炉中采用螺旋选晶法制备Cr的质量分数为2%和4%的两种单晶高温合金,保持其他合金元素含量不变,用JMat Pro软件计算、光学显微镜、扫描电镜、热分析等方法研究Cr含量对单晶高温合金凝固特征和凝固组织的影响。结果表明:随着Cr含量的增加,合金的固相线、液相线降低,固溶热处理窗口变窄,而糊状区宽度增加,γ′相含量和组织不稳定性增加;合金一次枝晶间距稍有减小,共晶含量增加,合金元素的枝晶偏析程度增加;合金枝晶干、枝晶间的γ′相尺寸减小,其均匀化和立方化程度稍有增加。To obtain the effect of Cr on the single crystal superalloy,the single crystal superalloy with 2%Cr and 4%Cr was cast with a directionally solidified furnace,while other alloying element contents were kept unchanged. The effects of Cr content on the solidification characteristic and microstructure of the alloy were investigated by JMat Pro software,OM,SEM and DTA. The results show that with the increase of Cr content,the solidus and liquidus temperature decreases and the heat treatment window narrows and temperature range of mush zone becomes wide,the volume fraction of γ′ phase and microstructure stability decrease. The primary dendrite arm spacing slightly decreases,the volume fraction of γ- γ′ eutectic increases,the element segregation extent increases with the increase of Cr content. The size of γ′ phase in the dendrite core and interdendrite region decreases and becomes uniform and its cubic shape turns a little regular with Cr content increasing.

关 键 词：单晶高温合金 CR含量 凝固 组织 

分 类 号：TG132.3[一般工业技术—材料科学与工程]