截面尺寸和固溶制度对单晶高温合金DD33中显微孔洞的影响  

Effect of Section Size and Solution Treatment on Micropore of a Third-Generation Single Crystal Superalloy DD33

作　　者：韩东宇 姜卫国[1] 肖久寒[1] 李相伟[1,2] 楼琅洪 HAN Dongyu;JIANG Weiguo;XIAO Jiuhan;LI Xiangwei;LOU Langhong(Institute of Metal Research, Chinese Academy of Sciences, Shenyang 110016, China;School of Materials Science and Engineering, University of Science and Technology of China, Shenyang 110016, China)

机构地区：[1]中国科学院金属研究所,沈阳110016 [2]中国科学技术大学材料科学与工程学院,沈阳110016

出　　处：《材料研究学报》2018年第3期168-176,共9页Chinese Journal of Materials Research

基　　金：国家自然科学基金(51674235;51671196;51401216和51701220)~~

摘　　要：研究了截面尺寸和固溶制度对DD33单晶高温合金中显微孔洞的影响。结果表明:随着截面尺寸的增大铸态合金的枝晶间距增大,共晶的含量提高。合金中的铸态微孔存在于共晶附近,其体积分数随着截面尺寸的增大稍有提高。在固溶制度相同的条件下,随着截面尺寸的增大残余共晶的含量和微孔的体积分数增加。当截面尺寸相同时,随着固溶温度的升高微孔体积分数增加。在固溶处理过程中各元素的不平衡扩散产生的Kirkendall效应导致合金内部固溶微孔的产生,不同截面尺寸造成组织偏析程度的不同是截面尺寸影响固溶微孔体积分数的主要原因。根据叶片的组织演化规律,给出了叶片固溶制度的设计方案并进行了实验验证。The effect of section size and solution treatment process on micropore of a nickel-based single crystal superalloy DD33 was investigated by optical microscope（OM）and scanning electron microscope（SEM）.The results show that the primary dendrite arm spacing and the volume fraction of eutectics increase with the increasing of section size in the as-cast alloys.Solidification micropores occur at locations near the eutectic.The volume fraction of solidification micropores increases slightly with the increasing of section size.After the same solution treatment for alloys,the volume fractions of residual eutectics and micropores increase with the increasing of section size.Under the condition of the same section size,the volume fraction of micropores increases with the increasing of solution temperature.The formation of internal micropores is due to the Kirkendall effect induced by imbalanced diffusion of the elements during solution treatment.The different section sizes of castings lead to the different segregation degrees,which results in the different volume fractions of the homogenization micropores.According to the evolution of microstructure of the blade,the appropriate solution treatment process was designed and then verified experimentally.

关 键 词：金属材料 单晶高温合金 截面尺寸 固溶制度 显微孔洞 

分 类 号：TG146[一般工业技术—材料科学与工程]