(燕山大學(xué) 材料科學(xué)與工程學(xué)院，亞穩(wěn)材料制備技術(shù)與科學(xué)國(guó)家重點(diǎn)實(shí)驗(yàn)室，河北省金屬產(chǎn)品工藝與性能綜合優(yōu)化實(shí)驗(yàn)室，秦皇島 066004)
摘 要: 以AZ31鎂合金為實(shí)驗(yàn)材料，通過(guò)多道次溫軋工藝，研究低溫時(shí)效處理對(duì)溫軋板材組織和性能的影響。結(jié)果表明：經(jīng)5道次溫軋后合金組織得到明顯細(xì)化，從初始態(tài)38 μm細(xì)化至2.2 μm；在隨后120~160 ℃時(shí)效過(guò)程中，晶粒并未發(fā)生顯著長(zhǎng)大。經(jīng)低溫時(shí)效處理后，合金在基本保持溫軋態(tài)拉伸強(qiáng)度的同時(shí)，其塑性得到明顯提升。由晶界強(qiáng)化和位錯(cuò)強(qiáng)化模型定量描述發(fā)現(xiàn)，經(jīng)5道次溫軋后合金顯微硬度增量為30HV。然而隨著時(shí)效溫度的升高，位錯(cuò)強(qiáng)化貢獻(xiàn)顯著降低，而晶界強(qiáng)化由于晶粒長(zhǎng)大不明顯而幾乎無(wú)顯著變化。合金經(jīng)160 ℃時(shí)效2 h后，兩種主要強(qiáng)化機(jī)制對(duì)顯微硬度的貢獻(xiàn)為16HV。
關(guān)鍵字: AZ31鎂合金；溫軋；時(shí)效；顯微組織；孿晶
（State Key Lab of Metastable Materials Science and Technology, Hebei Key Laboratory of for Optimizing Metal Product Technology and Performance, College of Materials Science and Engineering, Yanshan University, Qinhuandao 066004, China）
Abstract:AZ31 magnesium alloy was used as experimental material to study the influence of low temperature aging treatment on the microstructure and properties of warm rolled sheet by multi-pass warm rolling process. The results show that the alloy microstructure is remarkably refined after 5 passes of warm rolling, from 38 μm in the initial state to 2.2 μm, and no significant growth occurs during the subsequent aging at 120 ℃ to 160 ℃. After low temperature aging treatment, the alloy maintains the tensile strength in the warm-rolled state, and its plasticity is obviously improved. Quantitative description by grain boundary strengthening and dislocation strengthening model shows that the microhardness of the alloy increases by 30 HV after 5 passes of warm rolling. However, with the increase of aging temperature, the contribution of dislocation strengthening is significantly reduced, and the grain boundary strengthening has almost no significant change due to the inconspicuous grain growth. After being aged at 160 ℃ for 2 h, the contribution of the two main strengthening mechanisms to microhardness is 16HV.
Key words: AZ31 magnesium alloy; warm rolling; aging; microstructure; twins
