Mechanical Properties of Titanium Alloys for Automotive Engine Applications

Recently, there has been increased interest in titanium alloys for advanced automotive engine components to satisfy current demands for increased fuel economy. Titanium alloys offer a unique combination of high strength-to-weight ratio, good corrosion resistance and favorable high temperature mechanical properties. While widespread acceptance has been limited by production cost relative to other competing common materials, new technology improvements will enhance utilization of these alloys by decreasing material processing costs and increasing productivity. For the applications to automotive engine components, high temperature near-α type titanium alloys, mainly, were considered and Mechanical properties were charcterized at room temperature and elevated temperatures. Especially, for these applications, there is a need to understand creep behavior as a function of microstructure at 650°C and 760°C where creep will be one of the important limiting factors in service life time. Up to now, the use of conventional titanium alloys has generally been limited to 590°C or below and little data exists concerning creep behavior at higher temperatures. In addition, in this paper, thermal stabilities of near-α titanium alloys will be discussed at either high temperature.