半连续铸造Al-15Si合金热压缩变形流变应力行为  

Flow Stress Feature of DC Cast Al-15Si Alloy Under Hot Compression Deformation

作　　者：王春霞[1] 于福晓[2] 赵骧[1] 左良[1] 

机构地区：[1]东北大学材料各向异性与织构教育部重点实验室,辽宁沈阳110819 [2]东北大学材料与冶金学院,辽宁沈阳110819

出　　处：《东北大学学报（自然科学版）》2012年第6期827-831,共5页Journal of Northeastern University(Natural Science)

基　　金：国家自然科学基金资助项目(50734006;50771030);国家高技术研究发展计划项目(2007AA03Z516;2008AA030701);国家科技支撑计划项目(2009BAE80B01)

摘　　要：采用Gleeble-1500D热模拟机进行高温等温压缩试验,研究了半连续铸造Al-15Si铝合金在变形温度为300~500℃,应变速率为0.001~5 s-1条件下的流变应力行为.结果表明,在试验温度范围内,此合金的流变应力随变形温度的升高,应变速率的降低而降低,说明该合金属于正应变速率敏感性材料;可采用Zener-Hollomon参数双曲正弦形式来描述Al-15Si合金高温塑性变形时的流变应力行为;σ解析表达式中材料常数A,α,n值分别为2.07×1012s-1,0.026 MPa-1,4.61,Al-15Si合金的平均热变形激活能Q为180.96 kJ/mol.The flow behavior of AI-15Si alloy during hot compression deformation was studied by isothermal compression test using Gleeble- 1500 thermal-mechanical simulator in the temperature range of 300--500℃ and strain rate range of 0. 001 --5 s 1. The results showed that the flow stress is controlled by both strain rate and deforming temperature. The flow stress decreases with increasing deforming temperature and increases with increasing strain rate, indicating that A1- 15Si alloy is a positive strain rate sensitive material. The flow behavior of AI-15Si alloy during high-temperature deformation could be represented by hyperbolic sinusoid function of Zener- Hollomon parameters. Structure factor A, stress level parameter a and stress index n in the analytical expressions of a are 2.07- 1012 s 1, 0. 026 MPa- 1, 4.61, respectively. The activation energy of the alloy for hot deformation is calculated to be 180.96 kJ/mol.

关 键 词：AL-SI合金 热压缩变形 流变应力 ZENER-HOLLOMON参数 热变形激活能 

分 类 号：TG146.2[一般工业技术—材料科学与工程]