研究了Ag Sn O2类材料单体触点在镦制过程中的开裂问题,并将银丝材料拉伸试验曲线转化成真应力、应变数据,拟合得到银丝材料流变应力数学模型。应用有限元方法,模拟了银单体触点的冷镦成形过程,得到了冷镦成形过程中的等效应变、应力分布情况。研究结果表明,拉应力越靠近外层越大,而径向压应力则越靠近外层越小,变形物体的单位压力从外向内逐渐增大,因此,触点最大直径处为易开裂位置。此外,准确预测了成形过程中材料产生裂纹缺陷的位置及裂纹程度,当变形达到材料Damage值时,裂纹开始形成,Damage值随变形程度的增加而上升。通过试验,对开裂模拟结果进行了验证,模拟结果与试验吻合较好。 The cracking problem of Ag Sn O2 single contact during the upsetting process was studied. The tensile test curve of silver wire was transformed into true stress and strain data to obtain the mathematical model of flow stress of silver wire. The finite element method was used to simulate the cold heading process of silver single contact, and the equivalent strain and stress distribution during the cold heading process were obtained. The results show that the larger the tensile stress is, the closer the radial compressive stress is to the outer layer. The unit pressure of the deformed object gradually increases from the outside to the inside. Therefore, the maximum diameter of the contact points is easy to crack. In addition, the location of crack defects and the degree of cracks in the material during the forming process are predicted accurately. When the deformation reaches the material damage value, cracks begin to form, and Damage value increases with the increase of the deformation degree. Through the experiment, the cracking simulation results are verified, and the simulation results are in good agreement with the experimental results.