(華南理工大學(xué) 國(guó)家金屬材料近凈成形工程技術(shù)中心，廣州 510640)
摘 要: 為了系統(tǒng)研究半固態(tài)7050鋁合金的觸變力學(xué)行為，采用Gleeble-3500熱模擬試驗(yàn)機(jī)對(duì)SIMA法制備的半固態(tài)7050鋁合金進(jìn)行單向壓縮試驗(yàn)，利用SPPS數(shù)理統(tǒng)計(jì)軟件擬合材料本構(gòu)模型，最后通過(guò)MSC.MARC軟件進(jìn)行半固態(tài)軋制過(guò)程的數(shù)值模擬。結(jié)果表明：7050鋁合金的壓縮流變應(yīng)力與溫度、應(yīng)變速率以及應(yīng)變具有相關(guān)性，在0.1~10 s-1的應(yīng)變速率范圍內(nèi)，流變應(yīng)力隨溫度的升高而明顯降低，隨應(yīng)變速率和變形量的增大而增大；利用壓縮試驗(yàn)測(cè)得真應(yīng)力—真應(yīng)變關(guān)系，可以建立半固態(tài)7050鋁合金分階段觸變變形的粘塑性本構(gòu)模型，該模型基于半固態(tài)材料的力學(xué)特性，并考慮液相分?jǐn)?shù)的影響；模擬計(jì)算得到的穩(wěn)態(tài)軋制力約為25 MPa，與實(shí)際軋制實(shí)驗(yàn)結(jié)果基本吻合，證明所建立的本構(gòu)模型是合理的。
關(guān)鍵字: 半固態(tài)；熱模擬；本構(gòu)方程；軋制
（National Engineering Research Center of Near-net-shape Forming Technology for Metallic Materials,
South China University of Technology, Guangzhou 510640, China）
Abstract:In order to investigate the thixo-forming deformational behavior of 7050 aluminum alloy systematically, the semi-solid material prepared by SIMA method was studied on the Gleeble-3500 material thermo-simulation machine via uniaxial compression tests. The viscoplastic model of flow stress at semi-solid temperature was established by using SPSS software. At last, the rolling process was simulated by MSC.MARC finite element software. The results show that, the compression flow stress of 7050 aluminum alloy has a close relationship with temperature, strain rate and strain. In the strain range from 0.1 s-1 to 10 s-1, the flow stress decreases significantly with the temperature increasing and rises considerably with the strain and strain rate increasing. The two-stage viscoplastic model of flow stress is established by using the obtained true strain—true strain rate curves, which considers the mechanical properties of semi-solid state material and liquid fractions. The simulation results show the stable rolling force is around 25 MPa, which agrees with experimental results. So, the established constitutive equations are reasonable.
Key words: semi-solid; thermo-simulation; constitutive equations; rolling
