Review of the Effect of Oxygen on Titanium and Deoxygenation Technologies for Recycling of Titanium Metal

摘要

The high reactivity and poor machinability of titanium contribute to its high-cost fabrication, low material utilization rate, and large amount of titanium scrap production. Titanium scrap is mainly contaminated by oxygen and forms an oxygen-enriched layer on the surface of titanium. Oxygen has a deleterious effect on the ductility, toughness, and notch sensitivity of titanium but strengthens it. Traditionally, the contamination was removed by mechanical grinding and chemical acid cleaning. However, these processes generate substantial waste products and cause environmental problems. Deoxygenation is an alternative method for recycling of titanium and is critical when producing high-value powder products from the scrap. The typical deoxygenation technologies include thermochemical and electrolysis methods. This article mainly reviews the effect of oxygen on titanium and several deoxygenation technologies for recycling of titanium. The fundamental theory behind deoxygenation is included as well.