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本文从微观入手对金属压力成型过程中摩擦的形成原因进行了分析 ,认为摩擦是由于变形金属被压入工具表面的凹坑所引起的。摩擦功率等于此部分金属的变形功率 ,当它的变形功率大于在界面产生剪切流动的功率时 ,摩擦由滑动摩擦转变为粘着摩擦。同时 ,根据对工具表面的某些假设 ,推导了摩擦应力与粗糙度和静水压应力等之间的关系 ,并求出了发生粘着摩擦所需的静水压应力。计算结果表明 ,建立的摩擦模型是比较有效和合乎实际的 ,它为理论计算摩擦提供了方法。
In this paper, the cause of friction in metal forming process is analyzed from the microscopic point of view. It is believed that the friction is caused by the deformation metal being pressed into the pits on the surface of the tool. The frictional power is equal to the deformation power of this part of the metal. When its deformation power is greater than the shear flow power at the interface, the friction changes from sliding friction to adhesion friction. At the same time, according to some assumptions on the surface of the tool, the relationship between frictional stress, roughness and hydrostatic stress is deduced, and the hydrostatic stress required for adhesion friction is obtained. The calculation results show that the established friction model is more effective and realistic, which provides a theoretical method for calculating friction.