Low-Oxygen and Dense Mo10Cr Alloys Prepared via In-Situ Nanocarbon Deoxygenation and Two-Step Pressurization Hot Pressing

Hot pressing is a promising technique for fabricating high-density molybdenum (Mo) alloys; however, obtaining low oxygen content remains a significant challenge. In this study, Mo10Cr alloy billets were prepared by hot pressing with nanocarbon addition and a two-step pressurization strategy to reduce the oxygen content. Results show that the relative density of the Mo10Cr alloy increases with hot-pressing temperature and eventually remains above 98%, accompanied by grain growth and an increased degree of solid solution. The incorporation of nanocarbon facilitates in situ oxygen reduction during hot pressing under one-step pressurization, but this deoxygenation process is impeded by the applied pressure. In contrast, the two-step pressurization method effectively reduces the oxygen content of the nanocarbon-added Mo10Cr alloy to 169 ppm while maintaining a low residual carbon level. Furthermore, this approach significantly improves the compositional uniformity of the alloy. It is also observed that increasing the applied pressure promotes densification alongside grain growth. Consequently, the combination of two-step pressurization and in situ nanocarbon deoxygenation presents an effective pathway for fabricating dense, low-oxygen Mo alloys.