Ultrasonic Vibration-Assisted Milling of AISI H19 Hardened Hot Working Tool Steel

Abstract

Manufacturers, particularly those working in the mould and die industry, encounter several challenges in achieving the optimal surface finish. Approximately 40–60 HRC hardened hot working tool steel is used for the majority of the mould and die materials. Because of the tremendous strength of these materials, the conventional machining processes were limited in their capacity to machine them. When using conventional machining, it will encounter issues such as high tool wear rates and a poor machined surface finish. To address these issues, this research presented a hybrid machining method that incorporates ultrasonic vibration in an axial orientation into the conventional system tooling, referred to as ultrasonic vibration-assisted milling (UVAM), to solve the issues mentioned above. This research was undertaken to understand the effect of axial UVAM parameters on AISI H19 hardened hot working tool steel surface finish. To verify the efficiency of the suggested approach in improving the level of hardened AISI H19 tool steel machined surface roughness, we compared conventional milling (CM) to UVAM for various parameters, including milling spindle revolving speed, rate of feed and cutting depth. Axial UVAM dramatically reduced the machined surface roughness, with up to a 36.7% decrease in the value of Ra compared to the CM approach under the same cutting circumstances, according to the results of the milling tests. The surface prepared by UVAM was homogeneous and had proportionate peak-to-peak magnitude, which enhanced the surface quality, according to the macroscopic examination of the machined surface. Ra values have been strongly affected by the interlinkage between the cutting variables investigated. Continual hammering between the workpiece and cutter teeth greatly influences surface roughness, which is greatly influenced by frequency vibration. When ultrasonic vibration is applied, the level of surface roughness drops dramatically.