Howmet and Boeing-Seattle jointly evaluated the castability and mechanical characteristics of a modified Russian titanium alloy, Ti-5Al-5Mo-5V-3Cr-0.5Fe (Ti-5553), using wrought alloy starting stock supplied by Boeing. The casting studies conducted at Howmet showed the alloy to be comparable to Ti-6Al-2Sn-4Zr-2Mo-0.08Si (Ti-6242) in terms of castability. On the other hand, the strength and processing characteristics were similar to Ti-15V-3Al-3Cr-3Sn (Ti-15-3-3-3) alloy. Howmet initially cast several fluidity molds to evaluate castability and subsequently two bulkhead components as a test vehicle for further evaluation of castability. Cast material was also used to conduct heat treatment studies for the alloy, and an optimized heat treatment cycle was identified. Subsequently, Boeing and Howmet jointly conducted a mechanical property evaluation of the two bulkhead castings to characterize the static and dynamic behavior of the alloy. The hardenability of the alloy appears to be good, at least over the range of thickness examined (5 to 44.5-mm) and the room temperature strength characteristics can be controlled to fairly high levels (1138 - 1172 MPa UTS) with good ductility and toughness through controlled cooling and aging of the alloy from the solution temperature. The mechanical property results show the alloy to exhibit outstanding strength and HCF properties relative to Ti-6Al-4V. The results of the casting, heat treatment and mechanical testing efforts were presented at the 2003 Aeromat conference held in Dayton, Ohio (June, 2003).
|Number of pages||6|
|Journal||Journal of Advanced Materials|
|Publication status||Published - 1 Oct 2005|