(哈爾濱工業(yè)大學(xué)材料科學(xué)與工程學(xué)院， 哈爾濱 150001)
摘 要: 為研究LY12合金在半固態(tài)下的力學(xué)行為，使用拉伸與壓縮試驗(yàn)測(cè)定了LY12合金在不同半固態(tài)溫區(qū)及不同應(yīng)變速率下的真實(shí)應(yīng)力-真實(shí)應(yīng)變曲線，使用線性回歸方法確定了真實(shí)應(yīng)力σ與真實(shí)應(yīng)變速率ε·的關(guān)系及變形溫度與真實(shí)應(yīng)力的關(guān)系。結(jié)果表明， LY12合金在半固態(tài)溫區(qū)的拉壓變形行為均顯示出應(yīng)變速率敏感性, 其拉壓力學(xué)行為符合簡(jiǎn)單的冪函數(shù)關(guān)系σ＝kε·m。根據(jù)試驗(yàn)結(jié)果, 推算出了半固態(tài)LY12在不同變形溫度及應(yīng)變速率下的冪函數(shù)系數(shù)k、應(yīng)變速率敏感性指數(shù)m及變形激活能Q 的值，從而獲得了半固態(tài)LY12合金變形力學(xué)行為的定量描述。
關(guān)鍵字: LY12合金；力學(xué)行為；半固態(tài)；拉壓變形
（School of Materials Science and Engineering, Harbin Institute of Technology, Harbin 150001, P.R.China）
Abstract: In order to investigate the mechanical behavior of 2024Al alloy deformation at the semi-solid state, the tensile and compressive experiments were employed to measure its curve of true stress vs true strain at various deformation temperatures and strain rates. Based on the experimental results, the relation of true stress σ and true strain rate ε· and the relation of deformation temperature and true stress were determined using the method of simple linear regression. The results showed that the tensile and compressive deformation behaviors of 2024Al alloy in semi-solid state temperature regions display the sensitivity of strain rate and they could be expressed by a simple power law σ＝kε·m. In addition, the coefficient k of power law, the exponent m of sensitivity of strain rate and the energy Q of plastic deformation were derived based on the experimental results and theoretical analyses. Consequently, the quantitative description of 2024Al alloy deformation in the semi-solid temperature region was obtained.
Key words: 2024 alloy; mechanical behavior; semi-solid state; tension and compression deformation
