Deformation and damage mechanisms during thermal-mechanical fatigue of a single-crystal superalloy
Deformation and damage mechanisms during thermal-mechanical fatigue of a single-crystal superalloy
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DOI：
10.1016/j.actamat.2009.01.027
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发表时间：
2009-04-01
期刊：
影响因子：
9.4
通讯作者：
Reed, Roger C.
中科院分区：
文献类型：
--
作者：
Moverare, Johan J.;Johansson, Sten;Reed, Roger C.
研究了单晶高温合金CMSX-4在原始状态和1000 ℃长期暴露后的热机械疲劳变形和损伤机制。由于老化的机械响应的根本差异已被发现，这是由于在变形过程中的拓扑紧密堆积相的沉淀的趋势。在原始条件下，在结晶过程中的变形是非常本地化和集中的孪晶带延伸到整个横截面的试样;在这些带的相交处，材料易于再结晶。另一方面，时效材料表现出更分散的变形行为，其中孪晶的长度和厚度都小得多，没有发现再结晶，而是观察到显着的局部取向差，意味着在断裂后的老化材料中的晶体旋转。(C)2009 Acta Materialia Inc.由爱思唯尔有限公司出版。保留所有权利。
The deformation and damage mechanisms arising during thermal mechanical fatigue (TMF) of the single-crystal superalloy CMSX-4 have been investigated, both in the virgin condition and after long-term exposure at 1000 degrees C. Fundamental differences in the mechanical response due to ageing have been discovered, which are attributed to the tendency for the precipitation of topologically close-packed phases during deformation. In the virgin condition, the deformation during TMF is very localized and concentrated to twin bands which extend over the complete cross-section of the specimen; at the interception of these bands, the material is prone to recrystallization. The aged material on the other hand shows a much more dispersed deformation behaviour in which the length and thickness of the twins are much smaller and no recrystallization is found. Instead, significant local misorientations-implying crystal rotation are observed in the aged material after rupture. (C) 2009 Acta Materialia Inc. Published by Elsevier Ltd. All rights reserved.