单晶高温合金拉伸性能二次取向效应

Effects of Secondary Orientation on the Tensile Property of Single Crystal Superalloys

采用定向凝固方法制备了单晶高温合金二次取向试样,利用X射线衍射(XRD)、扫描电子显微镜(SEM)、拉伸实验等分析研究了不同温度下二次取向对单晶高温合金DD6拉伸性能的影响。结果表明,在650、760、980℃温度下,单晶高温合金拉伸性能具有二次取向效应。随着二次取向偏离度的增大,抗拉强度具有降低的趋势。在760℃温度下,二次取向效应最为显著,在980℃温度下,二次取向效应最弱。二次取向偏离较大时,反常屈服行为消失。

The effects of secondary orientation on the tensile property of single crystal superalloy DD6 were investigated, and the specimens used for characterizing secondary orientation were prepared by directional solidification. The tensile testing results,which were conducted at 650、760、980 ℃ respectively,indicate that secondary orientation had influence on the tensile property of single crystal superalloy by XRD、SEM and tensile test. The tensile strengths tended to decrease with increasing in misorientation of secondary orientation. The effect of secondary orientation was obvious at the condition of 760 ℃,while the influence was very weak at the condition of 980 ℃. The so-called abnormal yield phenomenon in single crystal superalloy disappeared when the misorientation of secondary orientation was high to some extent.