α-β型チタン合金の引張特性に及ぼすβ安定化元素量の影響

概要

論文の詳細を見る
Effects of β-stabilizer content in β phase at solution treatment temperature on microstructures after quenching from solution temperature, aging characteristics, and tensile properties were investigated by using 9 α-β titanium alloys (Ti-Al-V-Sn-Zr-Mo-Cr-Fe system). The main results obtained are as follows : (1) Partitioning of each element to α and β phases at solution treatment temperature could be well estimated from each Ti-j (j=Al, V, etc.) binary phase diagram. (2) Phase stability of β phase was considered to relate well with electron-atom ratio (e/a^β). Phase transformations in the alloys during quenching could be classified by e/a^β. From changes of electrical resistivity during heating, it was considered that athermal and isothermal ω phase were formed in the alloys GT-33, 45, and 46 (e/a^β=4.06-4.16). (3) Effects of microstructural and compositional factors (Volume fraction (V_α), grain diameter (d_α), and degree of solid-solution strengthening (dDE^α) for primary α phase, e/a^β for prior β phase, and aging temperature (T_<ag>) on tensile properties at 300℃ were examined by using multiple regression analysis. Following regerssion equations were obtained. σ_u(kgf/mm^2)=207.72-318.29V_α+119.43V_α・dDE^α+178(1-V_α)・(e/a^β-4)-19(1-V_α)・T_<ag>/100 El.(%)=-19.86-39.28V_α+13.08dDE^α+2.95T_<ag>/100
1986-02-01