铝钨粉末合金挤压成形与本构模型的建立  

Extrusion forming of aluminum tungsten powder alloy and establishment of constitutive model

作　　者：薛勇[1] 张治民[1] 张福祥[1] 刘翠侠[1] 

机构地区：[1]中北大学材料科学与工程学院,太原030051

出　　处：《塑性工程学报》2015年第2期111-116,共6页Journal of Plasticity Engineering

基　　金：国家973计划前期专项资助项目(2012CB626808);山西省自然科学基金资助项目(2013011022-5)

摘　　要：通过机械合金化方式将一定比例铝粉和钨粉合成一种性能优异的超固溶体铝钨合金粉末。通过研究铝钨粉末合金的冷压、热压制坯成形工艺，确定了主要挤压工艺参数，挤压件的致密度可达到99％左右；利用Gleeble‐1500热模拟机测试该合金在变形温度450℃～540℃、应变速率10－3 s－1～1s－1条件下的流变力学行为；采用Fields‐Backofen本构模型对该材料应力应变曲线进行拟合。并引入“软化因子”描述变形温度、应变速率和应变对流变应力的影响，进一步完善流变应力本构模型。Aluminum powder ,tungsten powder and other materials were selected in accordance with a certain proportion ,which was used to synthesize a kind of super solid solution alloy powder with excellent properties by mechanical alloying .A new technol‐ogy using cold and hot pressing extrusion to make billet of aluminum tungsten powder alloy was studied .The main parameters of the extrusion process were determined and the extrusion density reached about 99% .Based on the Gleeble‐1500 thermal mechani‐cal simulation ,the tests on the rheological behavior of this alloy at strain rate of 10-3 s-1 ~1s-1 and deformation temperature of 450 ℃ ~540 ℃ were taken .The Fields‐Backofen constitutive material model is used for the stress‐strain curve fitting .A “soften‐ing factor” was introduced to better describe the influence of deformation temperature ,strain rate and strain on the flow stress , and the flow stress constitutive model was further improved .

关 键 词：钨铝合金 热变形 本构方程 软化因子 

分 类 号：TG302[金属学及工艺—金属压力加工] TG146[一般工业技术—材料科学与工程]