SP-700鈦合金經固溶處理後，水淬合金微結構由αp(初析α)+ α”(麻田散鐵)+βr(殘留β)組成，於拉伸過程發生「應力誘發麻田散鐵」相變化，使βr轉變為α與α”造成強度上升，此時水淬合金同時具有高強度與高延性，經時效處理後α”與βr會分解析出α+β平衡相，使強度大幅提升但延性下降；空冷與爐冷合金由αp+α(析出相)+β(平衡相)組成，強度較水淬合金高，經時效後微結構形貌較無變化，強度僅小幅提升。綜合上述可知，考量SP-700鈦合金高強度特性，可由固溶水淬合金，經時效後得到；綜合拉伸性質，以固溶處理水淬合金較優良。According to this research, the microstructure of solution treatment by WQ alloy of SP-700 is constructed by αp(primary α）+ α”(martensite) + βr(retained β). Stress induced martensite transformation happened during tensile process, which makes strength superior due to βr transformed into α”. WQ alloy has high strength and ductility in the meanwhile. In addition, α” and βr is going to precipitate α+β stable phase by aging treatment. Aging makes WQ alloy became much stronger but poor ductility. The microstructure of AC and FC alloys are both formed by αp+α(precipitation)+β(stable), and have better strength than WQ alloy, but there is no phase transformation during aging treatment. From the above, solution treatment and aging of WQ alloy of SP-700, which has the best strength. Good tensile properties prefer WQ alloy without aging.
