轧制及退火对超轻双相镁锂合金组织和性能的影响..docVIP

轧制及退火对超轻双相镁锂合金组织和性能的影响 丁洪波1,2，1,2，1,2， （1. 中南大学材料科学与工程学院，湖南 长沙 410083；2. 中南大学有色金属材料科学与工程教育部重点实验室，湖南 长沙 410083；3. 江西省科学院江西省铜钨新材料重点实验室，江西 南昌 330029） 摘要：本文采用金相显微镜、扫描电子显微镜、万能试验机等实验方法轧制变形及退火等超轻双相Mg-8Li-3Al-0.4Y合金结果表明：α相β相沿轧制方向被拉长晶粒细化明显冷轧合金中αβ相延长，形成强烈的纤维组织冷轧合金350 oC×60 min退火处理后，大部分α相被球化，且组织完全再结晶。着时间的延长如90 mi时，合金发生了脱锂现象因此对于冷轧态双相镁锂合金薄板，最佳退火工艺制度为350 ×60 min， 此时合金延伸率达到35.27%。结合断口分析，热轧后退火处理合金断裂方式逐渐从脆性断裂向韧性断裂转变，冷轧合金薄板经退火处理后，其断裂方式逐渐由解理断裂向韧窝断裂转变。 关键词：；；； 中图分类号：T 文献标识码：A 文章编号： lloy Processed by Rolling and Annealing Treatments Ding Hongbo1,2, Zhou Haitao1,2, Peng Qianzhi1,2, Liu Keming3 （1. School of Materials Science and Engineering, Central South University, Changsha 410083, China; 2. Key Laboratory of Nonferrous Metal Materials Science and Engineering of Ministry of Education, Central South University, Changsha 410083, China; 3. Jiangxi Key Laboratory of Advanced Copper and Tungsten Materials, Jiangxi Provincial Academy of Science, Nanchang 330029, China） Abstract: mechanical properties of new superlight duplex phase Mg-8Li-3Al-0.4Y alloy during rolling and annealing treatments were investigated by optical microscopy, scanning electron microscope and universal testing machine. The results indicated that after hot-rolling process, the α phase and β phase were elongated in the rolling direction and the grains were refined obviously, and they were seriously deformed and exhibited slender structure after cold-rolling process. Spheroidization and fully static recrystallization occurred in the alloy during annealing at 350 oC for 60 min. However, when the annealing time increased to 90 min, the alloy suffered a serious Li loss. The annealing treatment after cold-rolling at 350 oC for 60 min was determined to be the optimal process for the Mg-8Li-3Al-0.4Y alloy because of the robust ultimate strength and elongation of the alloy with being 184.12 MPa and 35.27%, respectively. Brittle fracture and cleavage fracture were replaced by ductile fracture and dimple fracture