(1. 廣西大學(xué) 工程防災(zāi)與結(jié)構(gòu)安全教育部重點(diǎn)實(shí)驗(yàn)室，南寧 530004；
2. 廣西科技大學(xué) 職業(yè)技術(shù)教育學(xué)院，柳州 545006)
摘 要: 同時(shí)考慮滑移與孿生變形機(jī)制，在晶體塑性理論基礎(chǔ)上建立鎂合金晶體本構(gòu)關(guān)系，分別提出滑移與孿生變形的硬化函數(shù)，并考慮滑移與孿生變形間的交互作用；結(jié)合Voronoi多晶集合體代表性體積單元(RVE)，對(duì)AZ31鎂合金材料在單軸加載情形下進(jìn)行數(shù)值模擬實(shí)驗(yàn)及細(xì)觀分析。比較模擬結(jié)果與實(shí)驗(yàn)數(shù)據(jù)表明：采用晶體塑性本構(gòu)關(guān)系及硬化函數(shù)能夠合理預(yù)測(cè)鎂合金宏觀屈服行為、硬化演化與多晶織構(gòu)演化，并可合理估計(jì)多晶體內(nèi)的晶粒取向不均勻轉(zhuǎn)動(dòng)及晶粒內(nèi)產(chǎn)生孿晶的體積分?jǐn)?shù)分布。結(jié)果表明：鎂合金宏觀塑性行為取決于各滑移系與孿生系競(jìng)爭(zhēng)啟動(dòng)的結(jié)果；拉伸孿生變形是引起多晶體形成強(qiáng)基面織構(gòu)的主要原因；孿生變形導(dǎo)致晶粒取向轉(zhuǎn)動(dòng)與孿晶體積分?jǐn)?shù)在多晶體內(nèi)的分布極不均勻。
關(guān)鍵字: AZ31鎂合金；孿生變形；非均勻變形；多晶織構(gòu)；取向偏轉(zhuǎn)
（1. Key Laboratory of Disaster Prevent and Structural Safety, Guangxi University, Nanning 530004, China;
2. School of Vocational and Technical Education, Guangxi University of Science and Technology,
Liuzhou 545006, China）
Abstract:The constitutive relation of Mg alloy was established with the crystal plasticity theory based on the mechanisms of slip and twinning deformations. The hardening functions of slip and twinning deformations were proposed in consideration of the interaction between the slip and twinning deformation. The numerical simulation and meso analysis for AZ31 Mg alloy under the uniaxial loading were carried out using the above constitutive relation and the hardening functions associated with a representative volume element (RVE) consisting of Voronoi polycrystalline aggregation. By comparing the simulation results and the experimental data, the present method is verified feasible to predict reasonably the macroscopic yield behavior, the hardening evolution and the polycrystalline texture evolution. The reasonable estimations for inhomogeneous rotation of grain orientation and the twin volume fraction in the polycrystalline can be attained. The results show that, the macroscopic plastic behavior of Mg alloy depends on the competitive result of activation slip and twinning systems; the tension twin deformation is the primary reason to the formation of typical (0001) basal texture in the polycrystalline; and the twin deformation leads to extremely inhomogeneous distribution for the orientation deflection and the twin volume fraction in the polycrystalline.
Key words: AZ31 Mg alloy; twinning deformation; heterogeneous deformation; polycrystalline texture; orientation deflection
