(中國工程物理研究院，綿陽 621900)
摘 要: 研究淬火態(tài)和時效態(tài)U-Nb合金在機械加工和靜拉伸時的可逆塑性變形，采用透射電子顯微鏡進行原位拉伸觀察，結(jié)合變形前后及二次時效后合金的X射線衍射分析探討U-Nb合金的塑性變形機制，利用時效方法探索消除加工變形的可行性。結(jié)果表明：高密度孿晶的相互吞并、長大及發(fā)生擇優(yōu)取向是該合金在變形初期的主要變形機制；淬火態(tài)和經(jīng)150 ℃時效U-Nb合金的變形量差別不大，而經(jīng)200 ℃時效U-Nb合金的加工變形量與前兩者相比相對較小；利用200 ℃二次時效的方法消除塑性變形時，U-Nb合金的變形回復(fù)量可達50%以上。
關(guān)鍵字: U-Nb合金；形狀記憶效應(yīng)；變形；消除；孿晶；馬氏體
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
