Surface integrity analysis of SS316 Pocket milling by using abrasive water jet machining

Abstract

This work discusses the effect of abrasive jet path strategies and analyzes the method of machining, surface characterization of pocket milling on Stainless steel 316(ss316) by using abrasive water jet machining. As abrasive water jet machining is a prominent well proven technology among various nontraditional methods for machining of complex and intricate features. Abrasive water jet pocket milling is one such application which requires the optimization of process parameters such as pressure, standoff distance (SOD), abrasive flow rate (AFR) which influences the depth of pocket, material removal rate, surface roughness of the pocket. By considering the limitations, depth of pockets is machined by varying optimum process parameters and different pocket milling tool path strategies such as contour and raster jet path are used while machining. Optimized Surface generated by these jet path strategies were evaluated for their surface morphological studies at the start, middle and end of the pockets. Scanning electron microscope is used to observe the microstructure of the pockets. The results from the SEM images show that at the center of the pocket has no abrasive particle embedment and start& end of the pocket has more abrasive particle embedment in the raster path because of the jet lag for few seconds whereas in contour path the both ends of the pocket are with less particle embedment and start of the pocket in the contour path is middle, so there it has more particle embedment. Comparison between the both jet paths strategies are discussed in detail.