In Situ Study of the Mechanisms of High Temperature Damage in Elastic-Plastic Cyclic Loading of Nickel Superalloy
In Situ Study of the Mechanisms of High Temperature Damage in Elastic-Plastic Cyclic Loading of Nickel Superalloy
复制标题
镍高温合金弹塑性循环加载高温损伤机理的原位研究
DOI：
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发表时间：
2014
期刊：
影响因子：
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通讯作者：
K. Obrtlík
中科院分区：
文献类型：
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作者：
M. Petrenec;J. Polák;T. Šamořil;J. Dluhoš;K. Obrtlík
对铸造Inconel 713LC高温合金平板试样进行了635 °C的原位低周疲劳试验。本研究的目的是通过观察材料表面形貌特征及其伴随的内部位错结构来研究材料在弹塑性循环过程中的疲劳损伤机制。对表面上的选定位置进行了系统的原位研究，并通过SEM和AFM进行了记录。第一个拉伸半周的表面浮凸是由主滑移面（111）上的大量滑移台阶形成的。在接下来的压缩半周期中，形成了额外的反向滑动。在接下来的循环中，浮雕被修改，但没有在主系统中形成额外的新滑动痕迹。用EBSD测量了两个晶粒在标准区的再取向。在循环加载结束时，用透射电镜观察了材料表面持久滑移痕与材料内部持久滑移带的关系。早期阶段的挤压和ininsoluble形成的记录。损伤机制的演变与循环应变局部化到持久滑移带密切相关，持久滑移带也是疲劳裂纹萌生的场所。
In-situ Low Cycle Fatigue test (LCF) at temperature 635 °C have been performed in SEM on flat specimen ofcast Inconel 713LC superalloy. The aim of the investigation was to studymechanisms of the fatigue damage during elastic-plastic cycling by theobservations of the characteristic surface relief evolution and theaccompanying internal dislocation structures. The selected locations on thesurface were systematically studied in-situ and documented by SEM and usingAFM. The surface relief in the first tensile half-cycle was formed by numerousslip steps on the primary slip planes (111). In the following compressionhalf-cycle additional opposite slip were formed. The relief was modified in thenext cycles but without forming additionally new slip traces in the primarysystem. The reorientation of two grains in the gauge area was measured usingEBSD. At the end of cyclic loading the relation between surface persistent slipmarkings and persistent slip bands in the interior of the material wasdocumented by TEM on lamella prepared by FIB. The early stages of extrusion andintrusion formation were documented. The damage mechanism evolution is closelyconnected with the cyclic strain localization to the persistent slip bands thatare also places of fatigue crack initiation.