<001>取向偏离度对单晶高温合金热机械疲劳性能的影响及其机理研究

项目名称： <001>取向偏离度对单晶高温合金热机械疲劳性能的影响及其机理研究

项目编号： No.51201161

项目类型： 青年科学基金项目

立项/批准年度： 2013

项目学科： 金属材料学科

项目作者： 张炫

作者单位： 中国科学院金属研究所

项目金额： 25万元

中文摘要： 从单晶涡轮工作叶片制备与服役时面临的受力偏离<001>的实际问题，提炼出单晶高温合金热机械疲劳性能取向差各向异性的科学问题。以在国外大量使用并在国内具有广泛应用前景的Rene N5合金为研究对象，制备与<001>取向具有系列取向差（考虑偏离[001]和[010]）的单晶试棒，研究取向差对热机械疲劳性能的影响规律及作用机理。通过改变形变参数，研究不同偏离度下应力松弛、拉伸屈服及形变孪晶的形成条件。通过对断裂形貌和微观结构的分析，建立变形与断裂机制之间的关系。通过位错理论和晶格转动分析，确定滑移系类型。通过滑移系和层错类型来探求不同形貌孪晶的形成机理。澄清取向差影响单晶高温合金热机械疲劳各向异性的条件与作用机理，为涡轮叶片用单晶高温合金的可靠使用及失效分析提供新依据。

中文关键词： 热机械疲劳；单晶高温合金；各向异性；取向偏离度；

英文摘要： Based on the practical problems of loading axis off &lt;001&gt; during manufacture and service, misorientation anisotropy of thermal-mechanical fatigue property of single-crystal superalloy was brought out. All specimens were made of Rene N5 alloy, which is extensively being used all over the world and will be utilized in china.The behaviors and mechanisms of misorientation anisotropy were investigated using the single crystal specimens with different angle off &lt;001&gt; （including angle off [001]and [010]for one specimen）. The formation conditions of stress relaxation, tension yield and deformation twins were emphasized through changing the deformation parameters and specimens misorientation off &lt;001&gt;. The relationship of deformation and fracture mechanism were founded by anlysing the fracture morphology and deformation microstructure. The slip systmes were identified by analyzing dislocation vectors and lattice rotation. The formation mechanisms of different twins were investigated through slip systems and stacking faults analysis.The condition and deformation mechanism of anisotropy induced by misorientation off &lt;001&gt; during thermal-mechanical fatigue deformation were clarified, according to which the reliability in operation and failure analysis of single-crystal superalloy used for turbine blades were supported.

英文关键词： thermal mechanical fatgue；Single crystal superalloy；Anisotropy；Angle off <001>；