在拉伸过程中,金属材料与模具表面直接接触,且表面相互间的压力很大,材料在凹模表面滑动时,产生很大的摩擦。摩擦力增加了拉伸所需要的力和制件侧壁内的拉应力,因而对拉伸过程不利,易使制件破裂,造成废品。另外,材料与凹模的的摩擦还降低了模具的寿命和容易划伤制件表面。使用润滑剂后,可在材 During drawing, the metal material comes into direct contact with the mold surface, and the pressure between the surfaces is great. When the material slides on the surface of the concave mold, great friction occurs. Friction increases the force required for stretching and the tensile stress in the sidewall of the part, which adversely affects the stretching process and tends to rupture the part and cause waste. In addition, the friction of the material with the die also reduces the life of the die and easily scratches the surface of the part. After using the lubricant, can be in the material