The control of the post-forging cooling rate has been a key issue in the industrial production process of titanium alloys. We investigated texture evolution and variant selection(VS) during β → α transformation thr...The control of the post-forging cooling rate has been a key issue in the industrial production process of titanium alloys. We investigated texture evolution and variant selection(VS) during β → α transformation through high-temperature compression experiments followed by quantitative control of varying cooling rates. Results show that post-forging cooling rates affect β grains, α variants, and α/β textures. The αprecipitation inhibits motions of β static recrystallization(β_(SRX)) grain boundaries and thus leads to grain refining from 0.1 ℃/s to 0.05 ℃/s. Further analysis reveals that lamellae grain boundary widmanstattenα(α_(WGB)) keeps growing rapidly within β-grain in an interface instability manner at 0.1–0.05 ℃/s. Most of α-phase with 50°–60°/<-12–10> is preferentially precipitated at β-medium angle GBs between 30°and 45° and strictly follows BOR with the side of of adjacent β-grain with the same or similar {110} or{111}. Moreover, the texture type transforms gradually from RGoss {110} <1–10> to Brass {110} <1–12>from 25 ℃/s to 1 ℃/s. βgrains exhibit(102) [-201] texture, while the corresponding α has textures of<0001>//Z and <11–20>//Y from 1 ℃/s to 0.05 ℃/s. Our findings lay a profound theoretical foundation in microstructure evolution of near-β titanium alloy for industrial production.展开更多
文摘The control of the post-forging cooling rate has been a key issue in the industrial production process of titanium alloys. We investigated texture evolution and variant selection(VS) during β → α transformation through high-temperature compression experiments followed by quantitative control of varying cooling rates. Results show that post-forging cooling rates affect β grains, α variants, and α/β textures. The αprecipitation inhibits motions of β static recrystallization(β_(SRX)) grain boundaries and thus leads to grain refining from 0.1 ℃/s to 0.05 ℃/s. Further analysis reveals that lamellae grain boundary widmanstattenα(α_(WGB)) keeps growing rapidly within β-grain in an interface instability manner at 0.1–0.05 ℃/s. Most of α-phase with 50°–60°/<-12–10> is preferentially precipitated at β-medium angle GBs between 30°and 45° and strictly follows BOR with the side of of adjacent β-grain with the same or similar {110} or{111}. Moreover, the texture type transforms gradually from RGoss {110} <1–10> to Brass {110} <1–12>from 25 ℃/s to 1 ℃/s. βgrains exhibit(102) [-201] texture, while the corresponding α has textures of<0001>//Z and <11–20>//Y from 1 ℃/s to 0.05 ℃/s. Our findings lay a profound theoretical foundation in microstructure evolution of near-β titanium alloy for industrial production.
