摘要
采用梯度挤压工艺方案,并利用有限元仿真和试验相结合的方法,对Ti_(2)AlNb基合金的成形过程进行了系统研究。利用DEFORM软件分析了其成形过程中的载荷、应力、应变分布和金属流动行为,并结合Lode系数和应力三轴度对变形区的变形类型和应力状态进行了分析和表征。在RZU200HF液压机上进行了5A06铝合金物理网格试验和Ti_(2)AlNb基合金梯度挤压试验。结果表明,在Ti_(2)AlNb基合金梯度挤压成形过程中,塑性变形区的应力状态出现“三向压”和“一拉两压”情况。应变状态为压应力状态下的压缩类应变与伸长类应变。在坯料内部纵截面上,等效应变值从中心沿径向呈现上升梯度分布,应变梯度系数最大约为0.94。物理网格变化情况与数值模拟试验中基本一致,表层等效应变的理论计算值和网格试验值分别为4.06和4.27,验证了有限元模拟的有效性,且成功制备出Ti_(2)AlNb基合金成形件,为进一步制备高强塑性钛合金提供了参考依据。
The forming process of Ti_(2)AlNb-based alloy was systematically studied using the gradient extrusion process with the combination method of finite element simulation and tests. The distribution of load, stress, strain and the metal flow behavior during the forming process was analyzed by DEFORM software, and the deformation type and stress state in the deformation area were analyzed and characterized by Lode coefficient and stress triaxiality. Physical mesh tests of 5 A06 aluminum alloy and gradient extrusion tests of Ti_(2)AlNb-based alloy were carried out on RZU200 HF hydraulic press. The results show that during the gradient extrusion process of Ti_(2)AlNb-based alloy, the stress state in the plastic deformation area appears to be “three-way compression” and “one-tension-two-compression”. The strain states are compression-like strain and elongation-like strain under compressive stress state. In the internal longitudinal section of the billet, the effective strain shows an upward gradient distribution from the center along the radial direction and the maximum strain gradient coefficient is about 0.94. The physical mesh variation is basically consistent with that in the numerical simulation test, the theoretical calculated and mesh test values of the effective strain of the surface layer are 4.06 and 4.27, respectively, which verifies the feasibility of the finite element simulation. And the Ti_(2)AlNb-based alloy forming parts are successfully prepared, which provides a reference basis for further preparation of high-strength and plasticity titanium alloys.
作者
薛克敏
周金朝
郭胜华
闫中原
张勇强
李萍
XUE Ke-min;ZHOU Jin-zhao;GUO Sheng-hua;YAN Zhong-yuan;ZHANG Yong-qiang;LI Ping(School of Materials Science and Engineering,Hefei University of Technology,Hefei 230009,China)
出处
《塑性工程学报》
CAS
CSCD
北大核心
2022年第7期1-10,共10页
Journal of Plasticity Engineering
基金
国家自然科学基金资助项目(51975175,51875158)。
