IMPROVING THE PROPERTIES OF TITANIUM-ALLOYS BY ION-IMPLANTATION

Recent advances in the ion implantation process have shed light on the underlying mechanisms for improved surface properties of titanium alloys. Ion implantation of reactive species such as carbon or nitrogen creates hard-phase carbide or nitride precipitates which impart surface hardness to titanium alloys. Concurrently, the ion implantation process creates disorder in the surface of titanium and destroys the grain boundaries, and is responsible for lower friction of the surface. The ion implantation process duplicates shot peening on a microscopic scale and imparts compressive stress to the surface of the titanium, thereby improving high-cycle fatigue life of titanium components. Ion implantation also improves the resistance to corrosion and chemical etching of titanium surfaces. © 1990 TMS.