摘要
采用Deform-3D数值模拟软件对反复锻压模具结构和加工工艺进行有限元分析,发现：缩小模具型腔宽度能够增大试样每个锻压道次的等效应变,但应变分布均匀程度和试样形状尺寸保持度相应降低;模具存在一定的过渡角半径时,试样表面具有较好的成形质量,应变分布均匀性随着过渡角半径的增大有所提高;试样每道次锻压后绕Z轴旋转90°再进行下个道次锻压,等效应变分布比每道次锻压后试样不旋转更均匀;加工速度对锻压后试样的温升影响十分明显,速度越高温升越显著;随着锻压温度的提高,载荷峰值不断降低,试样中应变和应力分布逐渐均匀;随着摩擦系数的提高,等效应变分布均匀性有所改善,摩擦系数提高到0.2时分布最均匀,继续增大到0.3时分布均匀性开始显著降低.在300 ℃和0.1 mm·s-1条件下锻压AZ31镁合金的实验表明：5道次后晶粒显著细化,平均晶粒尺寸由约200 μm细化到最小约1.3 μm.
The die structure and processing technology of repetitive forging was analyzed by numerical simulation software Deform-3D. It is found that the equivalent strain of each forging pass is increased by reducing the width of mould cavity,however,the homogeneity of strain distribution and the shape and size retentivity of sample decrease. When a certain transitional angle radius existes in the mould,the sample surface obtaines a better forming quality,and the homogeneity of strain distribution is slightly improved with the increasing of transitional an-gle radius. While the sample is forged by next pass after it is rotated 90°around the Z-axis,more uniform effective strain distribution is ob-tained. Furthermore,the influence of processing speed on the temperature rise in the forged sample is very significant, and a higher speed makes the temperature rise remarkably. With the increasing of forging temperature,the maximum load decreases,while the homogeneity of strain and stress distribution in the sample increases. With the increasing of friction coefficient,the distribution uniformity of effective strain is slightly improved,and the most homogeneous strain distribution is obtained when it increases to 0.2,however,the distribution uniformity startes to de-crease obviously when it continues to increase to 0.3. The experimental investigation of forging magnesium alloy AZ31 at 300℃ with a speed of 0.1 mm·s-1shows that the average grain size is notably refined from about 200 μm to the minimum 1.3 μm after five passes.
出处
《锻压技术》
CAS
CSCD
北大核心
2018年第1期102-109,共8页
Forging & Stamping Technology
基金
国家自然科学基金资助项目(51404151,51561010,51461018)
江西省自然科学基金重大项目(20144ACB20013)
江西省科学院重点科研项目(2017-YZD2-20)
科研开发专项基金博士项目(2015-YYB-11)
协同创新专项普惠制一类项目(2015-XTPH1-11)
