超轻LAZ933合金热变形行为与应变补偿型本构模型  

Deformation Behavior and Constitutive Model for Strain Compensation of Ultra-light LAZ933 Alloy

作　　者：刘斌[1,2] 刘靓[2] 薛勇 LIU Bin;LIU Liang;XUE Yong(Shanxi Polytechnic College,Taiyuan 030006,China;School of Material Science and Engineering,North University of China,Taiyuan 030051,China)

机构地区：[1]山西职业技术学院,太原030006 [2]中北大学材料科学与工程学院,太原030051

出　　处：《精密成形工程》2025年第2期27-35,共9页Journal of Netshape Forming Engineering

基　　金：国家自然科学基金(52075501)。

摘　　要：目的研究超轻Mg-Li-Al-Zn合金LAZ933的热变形行为,为优化材料的性能提供依据。方法利用Gleeble-3800热模拟实验机开展热压缩实验,实验的变形温度分别为160、200、240、280、320℃,加热速率为5/s℃,保温5 min,应变速率分别为0.001、0.01、0.1、1、5 s^(-1),下压量为70%。结果流动应力-应变曲线主要受到材料加工硬化和动态软化的影响,不同实验参数得出的流动应力-应变曲线趋势类似。在应变速率维持恒定的情况下,合金的流动峰值应力随着变形温度的上升呈现出下降的趋势;当变形温度保持固定时,合金的流动峰值应力随着应变速率的增加而相应增大。合金的材料参数分别为α=0.018951966、n=3.96524、Q=123.865×10^(3)J/mol、ln A=26.60861。建立了LAZ933的Arrhenius本构模型Z=εexp(123.865×10^(3)/8.314T)=3.597×10^(11)[sinh(0.018951966×σ_(p))]^(-3.96524)。先利用不同应变下材料参数的五次多项式,计算得到了材料参数,然后根据本构方程对流动应力进行计算。流动应力计算值和实验值吻合度较高,计算值与实验值相关性较好,相关系数为0.97868,说明本构模型有较高的准确度。结论所提出的本构方程能够准确地估计LAZ933合金的流动应力,本构方程可靠,可用于描述实验合金的热变形行为以及分析成形过程中存在的问题,可以作为数值模拟的参考依据,并为改进合金的性能提供基础。The work aims to study the hot deformation behavior of ultra-light Mg-Li-Al-Zn alloy LAZ933 to provide a basis for optimizing the properties of the material.The Gleeble-3800 thermal simulation test machine was utilized to per-form the hot compression experiment.The deformation temperature of the experiment was 160,200,240,280 and 320℃,the heating rate was 5℃/s,the holding time was 5 min,the strain rate was 0.001,0.01,0.1 and 1,5 s^(-1)and the compres-sion amount was 70%.The flow stress-strain curve was primarily affected by the work hardening and dynamic softening of materials.The trend of the flow stress-strain curve remained consistent across different experimental parameters.Pro-vided that the strain rate remained unchanged,the peak flow stress of the alloy diminished with the augmentation of the deformation temperature.In contrast,when the deformation temperature remained steady,the peak flow stress of the alloy augmented in tandem with the increase of the strain rate.The material parameters of the alloy wereα=0.018951966、n=3.96524,Q=123.865×10^(3)J/mol,ln A=26.60861,respectively.The Arrhenius constitutive model of LAZ933 Z=εexp(123.865×10^(3)/8.314T)=3.597×10^(11)[sinh(0.018951966×σ_(p))]^(-3.96524)was established.By using the fifth degree polynomial of material parameters under various strains,the material parameters were initially calculated,followed by the calculation of flow stress based on the constitutive equation.The computed flow stress values exhibited an outstanding concordance with the experimental ones,and a powerful correlation was manifested,as evidenced by an impressive correla-tion coefficient of 0.97868.This clearly suggested the high precision and reliability of the constitutive model.The constitu-tive equation can accurately predict the flow stress of LAZ933 alloy.The constitutive equation is reliable and can effectively be used to describe the hot deformation behavior of the experimental alloy and analyze the issues in the forming process.It can be used as a reference for num

关 键 词：LAZ933合金 热压缩 流动应力-应变曲线 本构方程 应变补偿 

分 类 号：TG131[一般工业技术—材料科学与工程]