(1. 湖南科技大學(xué) 高功效輕合金構(gòu)件成形技術(shù)及耐損傷性能評價湖南省工程研究中心，湘潭 411201；
2. 湖南科技大學(xué) 高溫耐磨材料及制備技術(shù)湖南省國防技術(shù)重點實驗室，湘潭 411201；
3. 寧波大學(xué) 機械工程與力學(xué)學(xué)院，寧波 315211)
摘 要: 本文以預(yù)孿晶AZ31鎂合金為研究對象，結(jié)合黏塑性自洽(VPSC)模型仿真，研究中溫高速沖擊下預(yù)孿晶鎂合金的變形機理和力學(xué)行為，拓展了VPSC模型的應(yīng)用領(lǐng)域，為研究鎂合金動態(tài)載荷下的變形機理和力學(xué)行為提供了新的手段。結(jié)果表明：中溫高速沖擊過程中，基面滑移和二階錐面滑移是協(xié)調(diào)變形的主要機制，孿生也起到了重要的作用；大量孿晶的出現(xiàn)引起流變應(yīng)力在變形初期發(fā)生波動；壓縮孿晶的出現(xiàn)引起織構(gòu)最大極密度位置向半徑方向(Radial direction, RD)偏轉(zhuǎn)，二次孿晶的產(chǎn)生有利于形成雙峰織構(gòu)。
關(guān)鍵字: AZ31鎂合金；中溫高速沖擊；黏塑性自洽模型；力學(xué)行為；預(yù)孿晶；織構(gòu)
（1. Hunan Engineering Research Center of Forming Technology and Damage Resistance Evaluation for High Efficiency Light Alloy Components, Hunan University of Science and Technology, Xiangtan 411201, China;
2. Key Laboratory of High Temperature Wear Resistant Materials Preparation Technology of Hunan Province, Hunan University of Science and Technology, Xiangtan 411201, China;
3. Faculty of Mechanical Engineering and Mechanics, Ningbo University, Ningbo 315211, China）
Abstract:The deformation mechanism and mechanical behavior of pre-twinning AZ31 magnesium alloy under medium temperature with high speed impacting were investigated by combining the simulation of visco-plastic self-consistent (VPSC) model. This expanded the applications of VPSC model and provided a new approach to study the deformation mechanism and mechanical behavior of magnesium alloy under dynamic loading. The results show that during the medium temperature impacting, basal slip and second-order pyramidal slip are the dominant accommodation mode, and twinning also plays an important role. The flow stress fluctuates due to the occurrence of numerous twins. The maximum intensity position rotates toward RD for the onset of contraction twins. Double peak texture forms attributing to the activation of secondary twins.
Key words: AZ31 magnesium alloy; medium temperature impacting; visco-plastic self-consistent model; mechanical behavior; pre-twinning; texture
