砂轮约束磨粒喷射加工外圆表面创成机理及三维形貌

磨粒喷射精密光整加工是重要零件在磨削后进行去除表面缺陷层、降低粗糙度和波纹度为目的光整加工新工艺。试验在MB1332A外圆磨床上完成，加工试样为表面粗糙度0.6 m左右的45钢。加工表面形貌和微观几何参数分别用扫描电子显微镜和Micromesvre2表面轮廓仪测量。应用自相关函数对磨削加工表面和光整加工表面进行分析，并研究材料去除机理和微观表面形貌的创成机理。在楔形区游离磨粒获得能量对工件进行抛磨、滑擦、和微切削是材料去除机理的核心因素，磨料流体侧向挤出是均化和降低表面波纹度的主要因素。试验结果表明，试样表面从连续的方向一致的沟槽被随机不连续的微坑所代替，表面粗糙度明显得到改善。随着加工循环的增加，工件表面的粗糙度值由0.6 m下降到0.2 m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。

3D Profile and Generating Mechanism of Cylindrical Surface Lapping Machined with Abrasive Jet Flow Restricted by Grinding Wheel

The aim of abrasive jet flow finishing process as a new lapping techonology is to remove further the surface defect layer and diminish roughness and ripple. Experiments are performed on a cylindrical grinder MB1332A with a 45 steel workpiece as specimen of which the surface roughness values is 0.6 μm. The micromorphology of machined surface morphology is observed by using scanning electron microscope and the microcosmic geometry parameters are measured with Micromesvre2 profilometer. With ACF the surface during grinding and further lapping with liquid abrasive jet flow are researched. The material removal mechanism and the mechanism of surface morphology finished by the novel process is investigated. The energized free abrasives polish, wipe off and micro-cut the workpiece surface in wedge-like zone which is the main factor in material removal and the lateral extrusion of abrasive fluid is the main factor of homogenizing and lowering ripples. The result indicates that the machined surface changes from continuous parallel micro-groove to randomly distributed discontinuous micro-pit and the surface roughness values gradually decreases from an initial value of about 0.6 μm down to about 0.2 μm with the increase of machining cycles. Furthermore, the isotropy surface and uniformity veins both parallel and perpendicular machining direction are attained by the finishing process to improve greatly the wear resistance of the workpiece.