(1. 昆明理工大学材料科学与工程学院，昆明 650093；
2. 云南省钛材应用产品工程技术研究中心，楚雄 651209；
3. 云南钛业股份有限公司，楚雄 651209)
摘 要: 利用高速线材轧机制备Ti-6Al-4V合金小规格棒材(d10 mm)，研究固溶与时效热处理工艺对棒材显微组织与力学性能的影响。结果表明：棒材组织主要由α相和β相组成，随着固溶温度从900 ℃升高到990 ℃，棒材中α相含量减少而β相含量逐渐增多，显微组织出现了由初生等轴α相向针状β相转变进而向全片层状β转变的过程，棒材拉伸强度逐渐升高，而伸长率明显降低；棒材在930℃固溶后进行时效处理，随着时效温度从450 ℃升高到650 ℃，β相转变组织分解析出α相，组织主要由(α+β)相和β相混合组成，α相不断集聚长大，使组织粗大，棒材抗拉强度降低，伸长率升高；经(930 ℃，30 min，水淬)+(550 ℃，4 h，空冷)热处理后，棒材强度和塑性达到最佳配合，抗拉强度为1031 MPa，伸长率为12.5%。
关键字: Ti-6Al-4V合金；高速线材轧制；热处理；显微组织；力学性能
（1. School of Materials Science and Engineering, Kunming University of Science and Technology, Kunming 650093, China;
2. Engineering Technology Research Center of Titanium Products and Application of Yunnan Province,
Chuxiong 651209, China;
3. Yunnan Titanium Industry Co., Ltd., Chuxiong 651209, China）
Abstract:The small size bars of Ti-6Al-4V alloys (d10 mm) were prepared by high-speed rolling. The effects of solution and aging heat treatments on the microstructure and mechanical properties of the alloy bars were investigated. The results show that the alloy bars are mainly composed of α phase and β phase. With the solution temperatures increase from 900 ℃ to 990 ℃, the content of primary α phase decreases and the content of β phase increases, the microstructure transform procedure is observed in the alloy with the primary equiaxed α phase to the needle plexiform transformed β phase, and then to full lamellar transformed β phase. Furthermore, the tensile strength of the alloy gradually increases and the elongation significantly decreases. When the alloy is treated at the solution temperature of 930 ℃ and then aged at temperature from 450 ℃ to 650 ℃, the transformed β phase constantly precipitates α phase, and the microstructure of the alloy is consisted of the (α+β) phase and β phase. Meanwhile, the α phase grows up, and then the microstructure becomes coarse. Furthermore, the tensile strength of the alloy decreases and the elongation increases. As a result, after the heat treatment of (930 ℃, 30 min, WQ)+(550 ℃, 4 h, AC), this alloy bars have optimum mechanical properties, the tensile strength is 1031 MPa and the elongation is 12.5%.
Key words: Ti-6Al-4V alloy; high-speed rolling; heat treatment; microstructure; mechanical property
