(1. 安徽理工大學(xué) 材料科學(xué)與工程學(xué)院，淮南 232001；
2. 中南大學(xué) 粉末冶金國家重點實驗室，長沙 410083)
摘 要: 本文通過配置72個四元合金，利用X射線衍射(XRD)和掃描電子顯微鏡(SEM/EDS)測定了高強β型鈦合金Ti-Al-Mo-V-Cr體系中關(guān)鍵四元系Ti-Al-Mo-V、Ti-Al-Mo-Cr和Ti-Al-V-Cr含20 % Al (摩爾分?jǐn)?shù))時700和800 ℃的相平衡關(guān)系。實驗結(jié)果表明：Ti-Al-Mo-V體系存在3個兩相區(qū)(AlTi3+BCC_A2、AlMo3+BCC_A2、BCC_A2#1+BCC_A2#2)和1個單相區(qū)(BCC_A2)；Ti-Al-Mo-Cr體系存在1個四相區(qū)(AlMo3+BCC_A2#1+BCC_A2#2+Laves_C14)、2個三相區(qū)(AlMo3+BCC_A2+Laves_C14、AlTi3+BCC_A2+Laves_C14)、3個二相區(qū)(AlTi3+BCC_A2、AlMo3+BCC_A2、Laves_C14+BCC_A2)和1個單相區(qū)(BCC_A2)；Ti-Al-Cr-V體系存在1個三相區(qū)(AlTi3+BCC_A2+Laves_C14)、3個兩相區(qū)(AlTi3+BCC_A2、AlMo3+BCC_A2、Laves_C14+BCC_A2)和1個單相區(qū)(BCC_A2)。根據(jù)實驗結(jié)果，本文構(gòu)筑了這些四元系含20 % Al時700和800 ℃的等溫截面，為設(shè)計新型β鈦合金提供重要的理論指導(dǎo)。
關(guān)鍵字: Ti-Al-Mo-V-Cr；鈦合金；相平衡；相圖；實驗測定
（1. School of Materials Science and Engineering, Anhui University of Science and Technology, Huainan 232001, China;
2. State Key Laboratory of Powder Metallurgy, Central South University, Changsha 410083, China）
Abstract:Seventy-two quaternary alloys were prepared to investigate the phase equilibria of the Ti-Al-Mo-V, Ti-Al-Mo-Cr and Ti-Al-V-Cr systems at 700 and 800 ℃ with 20% (mole fraction) Al in the high strength β titanium alloy Ti-Al-Mo-V-Cr system by combining X-ray diffractometry (XRD) and scanning electron microscopy with energy dispersive X-ray spectroscopy (SEM/EDS) in the present work. The results show that there are three two-phase regions (AlTi3+BCC_A2, AlMo3+BCC_A2, BCC_A2#1+BCC_A2#2) and one single-phase region (BCC_A2) in Ti-Al-Mo-V system, one four-phase region (AlMo3+BCC_A2#1+BCC_A2#2+ Laves_C14) and two three-phase regions (AlMo3+BCC_A2+Laves_C14, AlTi3+BCC_A2+Laves_C14), three two-phase regions (AlTi3+BCC_A2, AlMo3+BCC_A2, Laves_C14+BCC_A2) and one single-phase region (BCC_A2) in Ti-Al-Mo-Cr system, and one three-phase region (AlTi3+BCC_A2+Laves_C14), three two-phase regions (AlTi3+BCC_A2, AlMo3+BCC_A2, Laves_C14+BCC_A2) and one single-phase region (BCC_A2) in the Ti-Al-V-Cr system at 700 and 800 ℃. The isothermal sections of these quaternary systems at 700 and 800 ℃ with 20% (mole fraction) Al are constructed, which are provided important theoretical guidance for designing new β titanium alloys.
Key words: Ti-Al-Mo-V-Cr; titanium alloy; phase equilibria; phase diagram; experimental determination
