论文部分内容阅读
本文研究了 Ti_3Al 基和 Ni_3Al 基合金室温下力学性能与裂纹扩展行为。研究结果表明:Ti_3Al 基合金主裂纹穿过母相,切过或绕过条状与块状α_2相,带有块状α_2组织的 Ti_3Al 基合金次生裂纹大都起始及中止于α_2相界;Ni_3Al 基合金基体可以产生交滑移,滑移线中止于第二相 NiAl 边界,最后于Ni_3Al/NiAl 相界处开裂;Ni_3Al 基合金增韧以裂纹转向与裂纹屏蔽为主,不同形态第二相对裂纹扩展阻力不同,其中长条状第二相扩展阻力大于短条状。Ti_3Al 基和 Ni_3Al 基合金裂纹扩展行为可直接与其宏观力学性能相关联。
In this paper, the mechanical properties and crack propagation behavior of Ti_3Al-based and Ni_3Al-based alloys at room temperature were investigated. The results show that the main cracks in the Ti_3Al - based alloy pass through the mother phase and cut or bypass the strip - shaped and massive α_2 phase. The secondary cracks of the Ti_3Al - based alloy with the massive α_2 structure start and stop at the α_2 phase boundary. Ni_3Al-based alloy matrix can produce cross-slip, the slip line stopped at the second phase NiAl boundary, and finally in the Ni_3Al / NiAl phase at the crack; Ni_3Al-based alloy toughened by crack steering and crack shield the second phase of the different forms Crack propagation resistance is different, in which the long bar second phase expansion resistance greater than the short bar. The crack propagation behavior of Ti_3Al-based and Ni_3Al-based alloys can be directly related to their macro-mechanical properties.