硼酸镁晶须增强镁基复合材料挤压过程数值模拟  

Numerical Simulation of Extrusion Casting Magnesium Borate Whisker Reinforced Magnesium Matrix Composite

作　　者：杨彩云[1] 李增苗[1] 朱云鹏[1] 金培鹏[1] 

机构地区：[1]青海大学新型轻合金重点实验室,青海省轻金属合金及深加工工程技术研究中心

出　　处：《特种铸造及有色合金》2016年第8期811-814,共4页Special Casting & Nonferrous Alloys

基　　金：青海省科技资助项目(2013-G-Q013A-3;2014-QGY-3)

摘　　要：对不同挤压工艺下Mg2B2O5w/AZ63B棒材的热挤压过程进行了有限元模拟,分析了热挤压过程中挤压温度(250、300、350℃)、挤压速度(1、4mm/s)和挤压比(6.25、14.00、20.25)对Mg2B2O5w/AZ63B复合材料挤压过程中等效应力的影响。模拟结果表明,温度对等效应力的影响最为显著,当挤压温度由250℃升至350℃时,合金的最大等效应力由185MPa降低到138MPa;当温度与挤压比恒定时,挤压速度从1mm/s增大到4mm/s时,最大等效应力值从184MPa降低到167 MPa;随着挤压比的增大,坯料在挤压筒内的等效应力逐渐增大,挤压坯料在挤压模具锥角处受到强烈的挤压变形和剪切变形,晶粒得到细化,使得等效应力的分布更加均匀。The finite element simulation of the hot extrusion process for the Mg2B2O5w/AZ63 Bunder different processes was carried out by using DEFORM-3Dsoftware.The effects of the varied extrusion temperatures（250 ℃,300 ℃,350 ℃）and speeds（1mm/s,4mm/s）as well as extrusion ratio（6.25,14,20.25）on equivalent stress of the extruded composites were analyzed.The simulation results reveal that temperature has significant role in equivalent stress,and the maximum equivalent stresses are decreased from 185 MPa to 135 MPa when the extrusion temperature is increased from 250℃to 350℃.In addition,the maximum equivalent stresses are decreased from 184 MPa to 167 MPa when the extrusion speed is increased from 1mm/s to 4mm/s at fixed ratio and temperature.With the increase of the extrusion ratio,the equivalent stresses of the billet in the extrusion chamber are increased and the extrusion billet in the die taper angle suffers a strong extrusion and shearing deformation.Therefore,the grains sizes are refined and the distribution of the equivalent stresses becomes more uniform.

关 键 词：挤压成型 数值模拟 等效应力 

分 类 号：TG376.2[金属学及工艺—金属压力加工] TB333[一般工业技术—材料科学与工程]