【摘要】 对亚共析U-Nb合金进行了不同形变量和不同拉伸速率的静态拉伸实验,利用光学显微镜、扫描电镜、X射线衍射仪和透射电镜分析了形变前后亚共析U-Nb合金微观组织结构的变化。结果表明:在低应变率范围内(10^-5～10^-2/s),亚共析U-Nb合金在形变过程中,其变形表面出现浮凸,随着形变量的增加,浮凸台阶增多。内部的孪晶马氏体相互合并长大并发生择优取向为亚共析U-Nb合金变形初期的主要变形机制。更多还原

【Abstract】 The static tensile test of uranium-niobium alloys near hypoeutectoid composition is done at different strains and tensile rates.The change of microstructure of uranium-niobium alloys near hypoeutectoid composition be- fore and after deformation is studied by optical microscopy,scanning electron microscopy,X-ray diffraction and trans- mission electron microscopy.The results show that the plica appears on the surface of uranium-niobium alloys during the deformation and the plica steps increase with the increase of the strain.The initial deformation mechanism is that twinning-martensites merge each other and reorientate due to the applied tension.更多还原