(中国工程物理研究院，绵阳 621900)
摘 要: 研究淬火态和时效态U-Nb合金在机械加工和静拉伸时的可逆塑性变形，采用透射电子显微镜进行原位拉伸观察，结合变形前后及二次时效后合金的X射线衍射分析探讨U-Nb合金的塑性变形机制，利用时效方法探索消除加工变形的可行性。结果表明：高密度孪晶的相互吞并、长大及发生择优取向是该合金在变形初期的主要变形机制；淬火态和经150 ℃时效U-Nb合金的变形量差别不大，而经200 ℃时效U-Nb合金的加工变形量与前两者相比相对较小；利用200 ℃二次时效的方法消除塑性变形时，U-Nb合金的变形回复量可达50%以上。
关键字: U-Nb合金；形状记忆效应；变形；消除；孪晶；马氏体
elimination method of U-Nb alloy
（China Academy of Engineering Physics, Mianyang 621900, China）
Abstract:The reversible plastic deformation during machining and static tensile test was studied for as-quenched and aged U-Nb alloy. The deformation mechanism of U-Nb alloy was probed by X-ray diffraction analysis and in-situ tensile test on transmission electron microscope. The feasibility of eliminating the machining deformation was probed by aging method. The results show that the growing up, incorporation and reorientation of martensite variants with high density twins is the primary deformation mechanism for U-Nb alloy at the initial stage of deformation. The plastic deformation in as-quenched and 150 ℃ aged U-Nb alloy after machining is similar, but larger than that of 200 ℃ aged alloy. The recovery deformation can reach 50% after the alloy aging at 200 ℃ for 30 min.
Key words: U-Nb alloy; shape memory effect; deformation; elimination; twin; martensite
