Surface carburizing during hot isostatic pressing

Abstract

The product preparation and surface carburizing of Ti–6Al–4V alloy are usually carried out separately, which leads to a low production efficiency and high processing costs. In this study, hot isostatic pressing (HIP) was proposed to complete the product preparation and surface carburizing of Ti–6Al–4V alloy simultaneously. Ti–6Al–4V powder compact with carburized layer is successfully fabricated using this method. X-ray diffraction and Energy dispersive spectrometer analyses illustrate the carburized layer is mainly composed of C, TiC and Ti. Scanning electron microscope shows a uniform TiC layer and an obvious diffusion region in the carburized layer and the total thickness is about 104 μm. The Ti–6Al–4V region is composed of equiaxed grains and typical lathlike structures. The Vickers hardness of the carburized layer especially the TiC layer is higher than the Ti–6Al–4V region. These results indicate that HIP is a promising process for product preparation and surface carburizing of Ti–6Al–4V alloy.