CAJ | 학술논문

利用热物理模拟机Gleeble1500进行多组圆柱试样的热物理模拟压缩试验,试验温度为250～450℃,应变速率为0.01～10 s~(-1).结果表明,7075铝合金热压缩温度在300、350、400和450℃时流变行为呈近稳态,而在250℃时呈非稳态.应用多元线性同归方法分析计算了7075合金唯象本构模型所需的一组系数及热变形的激活能.获得了能够较精确表示7075合金材料的流动应力与温度、应变速率和应变之间关系的唯象本构模型,为塑性成形模拟提供了所需的基本模型.
이용열물리모의궤Gleeble1500진행다조원주시양적열물리모의압축시험,시험온도위250～450℃,응변속솔위0.01～10 s~(-1).결과표명,7075려합금열압축온도재300、350、400화450℃시류변행위정근은태,이재250℃시정비은태.응용다원선성동귀방법분석계산료7075합금유상본구모형소수적일조계수급열변형적격활능.획득료능구교정학표시7075합금재료적류동응력여온도、응변속솔화응변지간관계적유상본구모형,위소성성형모의제공료소수적기본모형.
Several series of billet samples were compressed on heat physical simulation machine Gleeble1500 in the range of deformation temperature from 250℃ to 450℃,strain rate from 0.01 s~(-1) to 10 s~(-1).The results show that flow behavior of the material is unstable at 250 ℃,while near-steady-state at 300 ℃,350 ℃,400 ℃,450 ℃.A group of coefficients needed by the phenomenological constitutive model of 7075 aluminum and the activation energy of hot deformation are calculated by the method of multiple linear regression.The phenomenological constitutive model which can accurately describe the relationship between flow stress and temperature,strain rate and strain is achieved,and it offers the basic model for plastic forming simulation.