Development of New Titanium Compositions for Improved Medical Devices by Powder Metal Manufacturing Technology

Titanium alloys are used widely as medical implant materials because these alloys are biocompatible, easily fabricated, have excellent imaging characteristics and are amenable to a wide range of surface treatments. However the commonly used titanium alloys, CP Ti and Ti-6Al-4V, have limitations such as relatively poor wear resistance and an elastic modulus that is much higher than that of bone. While titanium alloys are available or can be designed to overcome these limitations there are two major barriers to the adoption of these alloys. First, medical applications use relatively small quantities of materials therefore it is difficult to justify the purchase of mill quantities of specialty alloys and the cost and lead time for alloy development. Second, potentially interesting titanium alloys are difficult to produce by conventional methods.

Dynamet Technology has developed an economical, advanced powder metallurgical process that can meet the requirements for relatively small quantities of specialty alloys expressly designed for specific medical applications. This process makes it possible to create unique titanium alloys with highly desirable properties that cannot be produced economically by conventional titanium manufacturing processes. Examples are titanium alloyed with tungsten; titanium alloyed with tantalum. and titanium metal matrix composites reinforced with ceramic. This paper discusses how Dynamet's technology is addressing specific implant applications including metal-on-metal spinal disc replacements, low modulus orthopaedic implants, nickel-free self deploying and mechanically deployed stents and dental posts and wires with enhanced properties.