Thermo-Mechanical Fatigue of the Monocrystalline Nickel-Base Superalloy CMSX-6
Thermo-Mechanical Fatigue of the Monocrystalline Nickel-Base Superalloy CMSX-6
复制标题
单晶镍基高温合金CMSX-6的热机械疲劳
DOI：
10.1520/stp16444s
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发表时间：
1996
期刊：
影响因子：
--
通讯作者：
H. Mughrabi
中科院分区：
文献类型：
--
作者：
S. Kraft;H. Mughrabi
对 γ 沉淀强化单晶镍基高温合金 CMSX-6 的接近 [001] 取向的生长试样进行了 600 至 1100°C 的总应变控制热机械疲劳 (TMF) 测试。应变-温度循环（同相、异相、金刚石）对 TMF 期间发生的机械和微观结构事件有很大影响。对于给定的温度间隔，异相测试的疲劳寿命最短，同相测试的疲劳寿命最长。对于所应用的所有循环形状，最大拉伸应力水平被认为是寿命限制因素。所研究合金的失效模式还取决于传导的应变-温度历史。虽然沿{111}面的强烈局部晶体剪切在同相和异相循环中占主导地位，但在金刚石循环测试中却发生了蠕变引起的损坏。还研究了微观结构的演变和粗化。后者与类似材料的蠕变测试中发现的应力、应变和扩散引起的粗化筏状结构的形成进行了比较。
Total strain-controlled thermo-mechanical fatigue (TMF) tests were performed between 600 and 1100°C on as-grown near to [001]-orientated specimens of the γ precipitate-strengthened monocrystalline nickel-base superalloy CMSX-6. The strain-temperature cycle (in-phase, out-of-phase, diamond) has a strong influence on the mechanical and microstructural events occurring during TMF. For given temperature intervals, the fatigue lives were shortest for out-of-phase tests and longest for in-phase tests, respectively. For all cycle shapes applied, the maximum tensile stress level was concluded to be the lifetime-limiting factor. The failure mode of the investigated alloy depends also on the conducted strain-temperature history. While strongly localized crystallographic shearing along {111} planes was dominant for in- and out-of-phase cycling, creep-induced damage occurred in diamond cycle tests. The evolution and coarsening of the microstructure were also studied. The latter is compared with the formation of stress-, strain- and diffusion-induced coarsened raft-like structures found in creep testing of similar materials.