模具粗糙度对板材拉延件摩擦特性的影响

EFFECT OF DIE SURFACE ROUGHNESS ON FRICTION CHARACTER OF PLATE DRAWN COMPONENT

金属板材拉延是一个复杂的塑性变形过程,广泛应用在各种大型汽车覆盖件等零件生产中。介绍了金属带料弯曲拉伸试验机的工作原理和试验方法。该试验机能很好地模拟凹模圆角区的摩擦场变化规律;通过选用不同的模具表面粗糙度,改变带料拉伸力、变形速度和成形头平均面压,测出摩擦因数的变化规律,用以研究模具表面粗糙度等对板材拉延件摩擦特性的影响。研究表明,适当降低模具表面粗糙度,有利于发展边界润滑,减少摩擦热的产生和作用。该研究方法把拉延过程中的摩擦、磨损和润滑有机地结合起来,为优化拉延件加工的摩擦条件奠定了理论基础。

The metal plate drawing is a complex process of plastic deformation.It is extensively applied to manufacturing product of all kinds of large-scale auto overlay parts and other parts.The working principle and test method of the metal strip bend tensile tester are detailed:this tester can exactly simulate the friction field change rule of the cavity die round angle band;measures the change rule of friction factor by selecting different die surface roughness,altering the tensile force and deformation velocity of strip and the mean surface pressure of forming roll. Study the effect of die surface roughness and other factors on the friction character of the stretched plate with this tester.lt is indicated that reducing die surface roughness properly is in favour of developing boundary lubrication,and reduces the generation and effect of the friction heat.The friction, wear and lubrication in drawing process are organically combined by this research technique.It provides the theoretical basis for optimizing friction conditions of machining drawn component.