论文部分内容阅读
本文研究了定向凝固镍基高温合金DZ5的高温瞬拉及持久断裂特性之晶体取向关系.试验于700、950℃两种温度条件下进行。用背反射劳埃法测定了试样拉伸轴偏离柱晶凝固方向〈100〉的真实偏角。结果表明,在700℃,瞬拉强度及持久寿命有明显取向关系.在偏角20°之内,上述性能急剧下降;而在950℃,尚未发现明显取向关系。上述取向关系用Schmid规律和交滑移强化机理得到合理解释。光学及电子扫描断口分析表明,随柱晶偏角增大,断裂特征有明显变化。
In this paper, the crystal orientation relationship between high-temperature instantaneous pull-down and permanent rupture characteristics of the directionally solidified Ni-based superalloy DZ5 was studied.The experiment was carried out at 700 and 950 ℃. The true declination angle of the tensile axis of the sample from the solidification direction of the columnar crystal <100> was measured by the back-reflection Railay method. The results show that there is a clear orientation between the instantaneous tensile strength and the long-term life at 700 ℃ .At the angle of 20 °, the above properties drop sharply; while at 950 ℃, no obvious orientation relationship has been found. The above orientation relationship is explained by Schmid’s law and cross-slip enhancement mechanism. Optical and electronic scanning fracture analysis showed that with the column crystal angle increases, the fracture characteristics of significant changes.