Effect of HIP parameters on surface integrity of machined HIP workpieces

Abstract

Hot isostatic pressing (HIP) materials with five relative densities of 99.8%, 99.4 %, 98.8%, 97.0% and 95.04% were prepared by HIP technology with five parameters and machined with coated cemented tool. Progressions of surface integrity of the machined HIP materials versus HIP parameter were studied. Heat conductivities, microstructures and mechanical properties of the HIP workpieces were varied, mainly because of the different pressing temperatures and pressing pressures. Chip-tool wear mechanisms also were changed with the HIP parameters due to the micro-voids of the workpieces. The phenomenon that the changing trends of the HIP workpiece surface integrities with cutting speed were not completely similar resulted from the varied thermodynamic properties and the different tool wear mechanisms in machining of the HIP materials.