基于Bauschinger效应的逆向精切削变形机理

Chip Deformation Mechanism of Reversible Fine Cutting Technique Based on Bauschinger Effect

基于工件材料Bauschinger效应,从已加工表面变质层的形成入手,建立了逆向精切削法的切削变形模型。利用金相显微试验技术对比研究了正、逆向精车削条件下工件材料晶粒流动情况,用位错理论对可逆向精切削的变形机理进行了论述。研究表明,可逆向切削时,可以采用首切时正向切削,复切(半精加工或精加工)时逆向切削的工艺路线,这样既可提高加工效率和加工精度,又可减小工件表面变质层。

Based on nonlinear hardening during reverse loading and the change of the Bauschinger effect factor with plastic strain, reverse loading released strain energy of elastic responses of machined underlayer. The chip deformation model of reversible finish cutting was established. Using metallographic micrographs, the difference between the advance and return stroke was analyzed in crystal slipping and elongating of the machined surface. The chip deformation mechanism of reversible finish cutting was discussed with dislocation theory. Research results indicted that it can be adopted such planning which rough machining during advance stroke and fine machining or semi - finishing during return stroke in machining process. In this way, it has such advantages that increase machining efficiency and machining accuracy, decrease deformation of the machined layer.