对AZ91D镁合金在不同切削速度下进行精密车削试验, 对比了不同工艺参数下切屑的断屑性能、形态及工件的表面质量。结果表明: 在背吃刀量恒定的前提下, 随着切削速度的增大、进给量的降低, 切屑的变形减小, 切屑形态由C形挤裂切屑变成带状切屑, 断屑性能变差, 工件表面质量变差; 在背吃刀量为0.06 mm时, 形成的粉末状切屑堆积在卷屑槽内, 易引起镁合金燃烧; 精密车削较佳的工艺参数为切削速度107.388 m·min-1, 进给量0.09 mm·r-1, 背吃刀量0.1 mm, 在此工艺参数下切削的工件符合设计要求。

The finish turning experiment of AZ91D magnesium alloy was carried out at different cutting speeds, and the breaking performance and shape of chips and surface quality of workpiecr at different process parameters were compared. The results show that, at the premise of constant cutting depth, with the increase of cutting speed and the decrease of feed, chip deformation decreased, chips shape changed from C shearing to strip, the breaking performance of chips and the surface quality of the workpiece all were poor grandually. Powder-like chips formed and accumulated in chip groove at the cutting depth of 0.06 mm, and thus to easily cause magnesium alloy combusting. The better cutting process parameters as follows: vc=107.388 m·min-1, f=0.09 mm·r-1, ap=0.1 mm, and the workpiece cutted at above parameters met the design requirements.