预应力切削过程刀具磨损的离散元模拟与试验研究

DEM Simulation and Experimental Study of Tool Wear in Prestressed Cutting Process

采用颗粒离散元法建立了描述切削过程中陶瓷刀具与切屑摩擦磨损行为的离散元模型;基于预应力切削原理,设计了一种用于车削加工环类零件的预应力加载装置,采用Sialon陶瓷刀具对GH4169环类工件进行了预应力车削试验,结合离散元模拟分析了预应力切削条件下切削力和刀具磨损的变化规律。结果表明:随着预应力的增大,预应力对刀具的磨损形态和机理没有明显的影响,刀具磨损随预应力的增大逐渐减小,在一定范围内提高切削速度可减少刀具的磨损。离散元模拟结果与试验结果具有一致性,验证了应用离散元模拟陶瓷刀具磨损的可行性。

The discrete element method( DEM) model which describes the friction and wear behavior of the interface between Sialon ceramic tool and chip was established. Based on the prestressed cutting principle,a specific preload device was designed for the prestressed turning of GH4169 ring parts; experimental validations were carried out with Sialon ceramic tools. Combining the experiments and DEM simulation,the cutting force and tool wear were investigated in different prestress conditions. It is found that the prestress shows little effect on wear appearances and mechanisms of ceramic tool. Both experiments and DEM simulation indicate that prestressed cutting method is benefit for the wear of Sialon ceramic tools. Moreover,within a certain range of prestress,higher cutting speed effectively results in slighter tool wear. The DEM simulation results are in good agreement with the experiments,which are further validated that DEM is feasible to simulate the tool wear behaviors.