“挤镦”剧变形力学模型建立  

Mechanical Modeling of the Severe Deformation of“Extrusion Upsetting”

作　　者：王珍 张治民[2] 于建民[2] 程眉[2] WANG Zhen;ZHANG Zhimin;YU Jianmin;CHENG Mei(School of Intelligent Manufacturing Engineering,Shanxi College of Technology,Shuozhou 036000;School of Materials Science and Engineering,North University of China,Taiyuan 030051)

机构地区：[1]山西工学院智能制造工程学院,朔州036000 [2]中北大学材料科学与工程学院,太原030051

出　　处：《机械工程学报》2024年第24期188-198,共11页Journal of Mechanical Engineering

摘　　要：针对“挤镦”剧变形过程缺少变形力的计算模型,无法进行设备选择、工艺设计及工装模具设计的现状,建立过程中的载荷求解模型。采用Deform-3D模拟软件研究了坯料尺寸、成形件尺寸及摩擦因数对于成形载荷的影响。由于变形特征为局部注入式镦粗变形的特殊性,传统力学模型无法进行计算,通过分析变形过程中的质点流动规律,提出新的边界条件假设。采用主应力法建立微小单元体的力学平衡方程,从而实现载荷模型的建立,并通过AZ80及VW124A两种典型镁合金进行物理试验验证。模型曲线的变化趋势与模拟曲线的变化趋势一致,表明所提出的边界条件假设是合理的,可用于“挤镦”剧变形的力能计算。但物理试验的变化趋势与之不同,是因为材料性能受应变状态的影响。成形载荷物理试验结果与计算结果偏差均小于10%,表明所建模型的合理性,为设备选择及工艺设计提供理论依据。Aiming at the lack of calculation model of deformation force during the deformation process of“extrusion upsetting”,which makes it impossible to carry out the current situation of equipment selection,process design and tooling design,the load solving model in the process was established.Deform-3D simulation software was used to study the effects of blank size,forming part size and friction factor on the forming load.Due to the special characteristics of the deformation feature of local injection upsetting deformation,the traditional mechanical model can not be calculated,by analyzing the mass flow law in the deformation process,a new assumption of boundary conditions is proposed.The mechanical equilibrium equation of the tiny unit cell is established by the principal stress method,so as to realize the establishment of the load model,and the physical experiment is verified by two typical magnesium alloys,AZ80 and VW124A.The trend of the model curve is consistent with that of the simulation curve,which indicates that the proposed assumption of boundary conditions is reasonable and can be used for the calculation of the force energy of the dramatic deformation of“extrusion upsetting”.However,the trend of the physical experiment is different because the material properties are affected by the strain state.The deviation between the physical experimental results of the forming load and the calculated results is less than 10%,which shows the reasonableness of the proposed model and provides theoretical basis for the equipment selection and process design.

关 键 词：“挤镦”剧变形 金属流动 变形假设 载荷求解模型 

分 类 号：TG312[金属学及工艺—金属压力加工]