论文摘要
The influences of different directional solidification processes, i.e., the high rate solidification（HRS） and liquid metal cooling（LMC）, on microstructure and stress rupture property of DD488 alloy were investigated. The DD488 alloy was directional solidified by both HRS and LMC processes. The microstructure and stress rupture properties at 980 ℃/250 MPa were investigated by using optical microscopy（OM）, scanning electron microscopy（SEM）, electron microprobe analyzer（EPMA）, transmission electron microscopy（TEM） and stress rupture testing. The results indicated that the LMC process refined the primary dendrite arm and decreased the microporosity volume fraction and solidification segregations of Cr and Co in as-cast DD488 alloy. After standard heat treatment of 1,260 ℃/4 h, AC（air cooling） + 1,080 ℃/4 h, AC + 870 ℃/24 h, AC, the γ′ morphology in LMC alloy was more cuboidal than that in HRS alloy, and the γ′ volume fraction of LMC alloy was higher than that of HRS alloy. The stress rupture life at 980 ℃/250 MPa of HRS alloy was 76.8 h, and it increased to 110.0 h in LMC al oy. The LMC process increased the stress rupture life due to the higher γ′ volume fraction, more perfect rafting structure and finer interfacial dislocation networks.
论文目录
文章来源
类型: 期刊论文
作者: Liang Luo,Cheng-bo Xiao,Jing-yang Chen,Qing Li,Sheng-long Dai
来源: China Foundry 2019年01期
年度: 2019
分类: 工程科技Ⅰ辑
专业: 金属学及金属工艺
单位: Science and Technology on Advanced High Temperature Structural Materials Laboratory, Beijing Institute of Aeronautical Materials
基金: financially supported by the National Key R&D Program of China(Grant No.2016YFB0701402),National Natural Science Foundation of China(Grant No.51771020),Aeronautical Science Foundation of China(Grant No.2015ZE21006)
分类号: TG132.3
页码: 8-13
总页数: 6
文件大小: 1322K
下载量: 26