基于磨粒特征尺寸与砂轮、工件间液膜厚度比值的变化研究了磨粒喷射光整加工的材料去除机理,建立了两体研磨及三体冲蚀单颗磨粒的材料去除模型和材料去除率模型。试验在MB1332A外圆磨床上完成,加工试样为Sa=0.6μm左右的45钢。加工表面形貌和微观几何参数分别用SEM和MICROMESVRE2表面轮廓仪测量,试验结果和材料去除模型相吻合。试样表面连续的方向一致的沟槽被随机不连续的微坑所代替,随着加工循环的增加,Sa值由0.6μm下降到0.2μm左右。此外,光整加工可以获得各向同性网纹交错的表面,表面轮廓的支撑长度率提高,对工件的耐磨性有利。
The material removal mechanism of Abrasive Jet Finishing(AJF) was investigated based on the size ratio of characteristic abrasive size to the film thickness between grinding wheel and workpiece. Two-body lapping and three-body erosion mode by a single abrasive and the mode of material removal rate were established. Experiments were performed on a cylindrical grinder MB1332A with a 45 steel workpiece as specimen of which the surface roughness values of Sa=0. 6μm. The micromorphology of machined surface morphology was observed using SEM and the microcosmic geometry parameters were measured with MICROMESVRE2 profilometer. It is found that experimental results match theoretical analyses. The machined surface changed from continuous parallel micro- groove to randomly distributed discontinuous micro-pit and Sa gradually decreased from an initial value of about 0. 6μm down to about 0. 2μm with the increase of machining circles. Furthermore,the isotropy surface and uniformity veins both parallel and perpendicular machining direction are attained by the finishing process to improve greatly the wearable capability of the workpiece.