中国有色金属学报
中國有色金屬學報
중국유색금속학보
THE CHINESE JOURNAL OF NONFERROUS METALS
2014年
2期
371-379
,共9页
半固态%热模拟%本构方程%轧制
半固態%熱模擬%本構方程%軋製
반고태%열모의%본구방정%알제
semi-solid%thermo-simulation%constitutive equations%rolling
为了系统研究半固态7050铝合金的触变力学行为,采用Gleeble-3500热模拟试验机对SIMA法制备的半固态7050铝合金进行单向压缩试验,利用SPPS数理统计软件拟合材料本构模型,最后通过MSC.MARC软件进行半固态轧制过程的数值模拟。结果表明:7050铝合金的压缩流变应力与温度、应变速率以及应变具有相关性,在0.1~10 s-1的应变速率范围内,流变应力随温度的升高而明显降低,随应变速率和变形量的增大而增大;利用压缩试验测得真应力-真应变关系,可以建立半固态7050铝合金分阶段触变变形的粘塑性本构模型,该模型基于半固态材料的力学特性,并考虑液相分数的影响;模拟计算得到的稳态轧制力约为25 MPa,与实际轧制实验结果基本吻合,证明所建立的本构模型是合理的。
為瞭繫統研究半固態7050鋁閤金的觸變力學行為,採用Gleeble-3500熱模擬試驗機對SIMA法製備的半固態7050鋁閤金進行單嚮壓縮試驗,利用SPPS數理統計軟件擬閤材料本構模型,最後通過MSC.MARC軟件進行半固態軋製過程的數值模擬。結果錶明:7050鋁閤金的壓縮流變應力與溫度、應變速率以及應變具有相關性,在0.1~10 s-1的應變速率範圍內,流變應力隨溫度的升高而明顯降低,隨應變速率和變形量的增大而增大;利用壓縮試驗測得真應力-真應變關繫,可以建立半固態7050鋁閤金分階段觸變變形的粘塑性本構模型,該模型基于半固態材料的力學特性,併攷慮液相分數的影響;模擬計算得到的穩態軋製力約為25 MPa,與實際軋製實驗結果基本吻閤,證明所建立的本構模型是閤理的。
위료계통연구반고태7050려합금적촉변역학행위,채용Gleeble-3500열모의시험궤대SIMA법제비적반고태7050려합금진행단향압축시험,이용SPPS수리통계연건의합재료본구모형,최후통과MSC.MARC연건진행반고태알제과정적수치모의。결과표명:7050려합금적압축류변응력여온도、응변속솔이급응변구유상관성,재0.1~10 s-1적응변속솔범위내,류변응력수온도적승고이명현강저,수응변속솔화변형량적증대이증대;이용압축시험측득진응력-진응변관계,가이건립반고태7050려합금분계단촉변변형적점소성본구모형,해모형기우반고태재료적역학특성,병고필액상분수적영향;모의계산득도적은태알제력약위25 MPa,여실제알제실험결과기본문합,증명소건립적본구모형시합리적。
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.