Metal injection moulding of titanium and titanium alloys: Challenges and recent development

Metal Injection Moulding (MIM) is a well-developed net or near-net shape manufacturing technique for stainless steel, copper and other metallic materials. This process has also received increasing attention over the last decade as a promising technique for the manufacture of small and intricate titanium parts for a range of applications in biomedical, aerospace, automotive and other industries. Historically, the necessity to use expensive fine spherical ( < 45 μm), low-oxygen titanium powder has hindered the industrial application of titanium MIM from an economic perspective. However, recent efforts have shown promise in adapting low-cost non-spherical hydride-dehydride (HDH) titanium powder to the MIM process. HDH powder is considerably less expensive than fine spherical powder and thus there is significant potential in expanding the application of titanium MIM. This paper reviews recent developments in MIM of titanium and its alloys as well as the outstanding challenges with a special focus on MIM of HDH titanium powder.