摘要
通过TEM研究了固溶态及直接时效态Inconel718合金的蠕变变形组织。结果表明:固溶态Inconel718合金,在550℃/220MPa条件下达到1%变形量时,蠕变组织的特征为位错交滑移;而直接时效态Inconel718合金,在680℃/650MPa条件下达到1%变形量时,蠕变组织中既有位错滑移后形成的变形带,又存在位错攀移,并且存在少量的孪晶变形。讨论了Inconel718合金中发生蠕变孪晶的机制,着重从γ″强化相的晶体学特征来解释该现象。研究结果认为:具有特殊结构的γ″强化相是影响合金蠕变变形机制的根源。
The creeping deformation has been investigated in homogenized and direct aged Inconel 718 alloys. The results show that they have different creeping microstructures; the cross slip of dislocation is the typical deformation model when the homogenized Inconel 718 alloy is creeping to stain of 1% at 550 ℃ under 220 MPa; and the complicated deformation microstructures are observed when the directly aged Inconel 718 alloy is creeping to stain of 1% at 680 ℃ under 650 MPa; either slip bands, or dislocation climbs and some deformation twins are all observed in the creeping microstructures. The complex phenomenon of twining is discussed based on the crystallographic structure. Finally, it is considered that the strengthening phase γ＂ is responsible for the creeping deformation mechanism.
出处
《稀有金属材料与工程》
SCIE
EI
CAS
CSCD
北大核心
2007年第11期1924-1927,共4页
Rare Metal Materials and Engineering
基金
国家自然科学基金资助(50271072
50471083)
