摘要
利用红外加热环境模拟系统对定向凝固Ni_3Al基合金进行1100℃的热冲击,利用光学显微镜和扫描电镜观察了合金的组织及裂纹形貌.热冲击实验结果表明,经受热冲击后合金的蠕变寿命下降,冲击次数越多则蠕变寿命降幅越大.显微组织观察表明,经过1100℃热冲击后,合金中的γ′粒子发生粗化,且粗化具有一定的方向性;同时,合金中MC碳化物分解为M_6C和γ′.γ′粒子粗化及其体积分数的减少是蠕变性能降低的主要原因.
Infrared rapid heating system was used to study the effects of heat shocking on microstructure and creep performance of a directionally solidified Ni3Al base alloy. After heat shocking for 200, 400, 600 and 800 cyc at 1100℃, the sample＇s creep performances at 980℃, 218 MPa were tested. Observation of the microstructure indicated that γ′ precipitates coarsened after heat shocking, at the same time, the MC carbides at boundary and interdendritic decomposed to M6C and γ′. Creep life of the alloy decreased largely after heat shocking due to coarsening of γ′ precipitate and reducing of γ′ volume.
出处
《金属学报》
SCIE
EI
CAS
CSCD
北大核心
2008年第5期547-550,共4页
Acta Metallurgica Sinica
