| Title |
Aging behavior and Mechanical Properties of Ti-15-3 Alloy |
| Authors |
김성준(S . J . Kim) ; 최병학(B . H . Choe) ; 추원익부(M . Hagiwara) |
| Abstract |
The effects of aging treatment on the microstructures and mechanical properties of metastable beta titanium alloy Ti-15-3(Ti-15V-3Al-3Sn-3Cr) has been investigated with hardness measurement, tensile test, and optical and electron microscopy. Precipitate-free beta structure with average grain size about 56 ㎛ was obtained after solution treatment at 800℃ for 15 min followed by air cooling. Solution treated specimens were aged up to 800 hrs in the temperature range between 350 and 600℃. The morphology of preapitates was significantly varied depending on the aging temperature. Fine aggregates of a precipitates were dominant at 350℃, while Widmansta¨tten α precipitates were dominant at above 450℃. Peak hardness values were maintained up to 800 hrs at 500℃, which showed the superior thermal stability of α precipitates. Tensile strength increased up to 1600㎫ along with the decrease of elongation after aging at 350 and 400℃. Fracture surfaces changed from transgranular ductile mode to intergranular brittle mode as the strength increased with aging. |