(1. 昆明理工大學(xué)材料科學(xué)與工程學(xué)院，昆明 650093；
2. 云南省鈦材應(yīng)用產(chǎn)品工程技術(shù)研究中心，楚雄 651209；
3. 云南鈦業(yè)股份有限公司，楚雄 651209)
摘 要: 利用高速線材軋機(jī)制備Ti-6Al-4V合金小規(guī)格棒材(d10 mm)，研究固溶與時(shí)效熱處理工藝對(duì)棒材顯微組織與力學(xué)性能的影響。結(jié)果表明：棒材組織主要由α相和β相組成，隨著固溶溫度從900 ℃升高到990 ℃，棒材中α相含量減少而β相含量逐漸增多，顯微組織出現(xiàn)了由初生等軸α相向針狀β相轉(zhuǎn)變進(jìn)而向全片層狀β轉(zhuǎn)變的過(guò)程，棒材拉伸強(qiáng)度逐漸升高，而伸長(zhǎng)率明顯降低；棒材在930℃固溶后進(jìn)行時(shí)效處理，隨著時(shí)效溫度從450 ℃升高到650 ℃，β相轉(zhuǎn)變組織分解析出α相，組織主要由(α+β)相和β相混合組成，α相不斷集聚長(zhǎng)大，使組織粗大，棒材抗拉強(qiáng)度降低，伸長(zhǎng)率升高；經(jīng)(930 ℃，30 min，水淬)+(550 ℃，4 h，空冷)熱處理后，棒材強(qiáng)度和塑性達(dá)到最佳配合，抗拉強(qiáng)度為1031 MPa，伸長(zhǎng)率為12.5%。
關(guān)鍵字: Ti-6Al-4V合金；高速線材軋制；熱處理；顯微組織；力學(xué)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
