半固態(tài)等溫組織的特征
( 1. 西安理工大學(xué) 材料科學(xué)與工程學(xué)院， 西安 710048;
2. 西北工業(yè)大學(xué) 材料科學(xué)與工程學(xué)院， 西安 710072)
摘 要: 研究了AZ91D鎂合金在應(yīng)變誘發(fā)熔化激活法處理過(guò)程中形變率和形變溫度對(duì)組織的影響。結(jié)果表明： 形變溫度為280℃時(shí)，隨著形變率增加， 部分枝晶臂逐漸伸長(zhǎng)， 枝晶破斷現(xiàn)象加劇； 形變率為20%時(shí)，隨著形變溫度的提高， 組織的形變方式逐漸由以枝晶斷裂為主轉(zhuǎn)變?yōu)閹в蟹较蛐缘膹澢?AZ91D合金在580℃等溫10min所獲得的半固態(tài)組織， 隨著形變率增加，球狀晶粒尺寸減小， 圓整度提高； 隨形變溫度的提高， 固相顆粒的偏聚現(xiàn)象減輕。
關(guān)鍵字: 應(yīng)變誘發(fā)熔化激活法; 鎂合金； 壓縮形變； 半固態(tài)組織
microstructures of AZ91D alloy for upsetting in SIMA process
JIANG Bai-ling1， TANG Wen-ting1
（ 1. School of Materials Science and Engineering,
Xi′an University of Technology,Xi′an 710048, China;
2. Department of Materials Science and Engineering,
Northwestern Polytechnical University, Xi′an 710072, China）
Abstract: The influences of strain and temperature on microstructure of AZ91D alloy for upsetting in the strain-induced melt activation process were investigated. The results indicate that with increasing the strain at 280℃, the dendrite arms of AZ91D alloy get broken or stretched-out. With increasing the predeformation temperature under 20% strain, the deformation style of the dendritic structure of AZ91D alloy changes gradually from fragmentation to directional bending. After held at 580℃ for 10min , the greater the strain, the finer and rounder the size of the globular grains of AZ91D alloy. And in the mean time, the higher the isothermal temperature, the less the agglomeration of solid particles.
Key words: train-induced melt activation; magnesium alloy; upsetting; semi-solid microstructure
