TC11合金的新型本构关系

A New Constitutive Relationship for TC11 Alloy

ＴＣ１１合金的新型本构关系刘东，罗子健所谓本构关系，指一种材料的流动应力与应变速率、变形温度和变形程度的关系．实质上，本构关系表示材料对热力参数变化的动态响应．因此，建立本构关系是制定材料塑性加工工艺、对材料塑性加工过程进行数值模拟的基础性工作．由于...

Engineers need constitutive relationship for planning how to get high- quality forgings.Arrhenius' equations, usually needed for finding constitutive relationship, are no longer satisfactory when materials are difficult to deform, such as titanium alloys and superallogs. We now present a method which uses the polynome of Zener-Hollomon parameter and is applicable to difficult- to- deform materials.As is well known, constitutive relationship is empirically found from test data. We obtain such a relationship for TC 11 alloy as a po1Ynome of Zener-Hollomon parameter from test data. The test specimens are Cylinders of TC11 alloy 8 mm in diameter and 12 mm in length,cut from the sa-me rod of TC11 alloy made by Bac n Non-Ferrous Metal Works. A computer- controlled hot working simulator . Thermecmastor- Z, is employed to obtain a under variouscombinations of B and T, where a is now stress, e is equivalent strain rate, and T is temperature. Tests ate conducted under isothermal conditions with ε kept constant. Test data reveal that: (1) ε exerts an influence on the shape of a--B curve, where ε is equivalent strain.(2) T exerts strong ialuence on both the shape of σ￣ε curve and the magnitude of σ. Thus the constitutive relationship for TC11 alloy can be expressed as eq. (1 ), where g = (1nZ -- E /T)/T, Z= ε. e-cp(θ/RT), Z is Zener-Hollomon parameter, f(T), A, B, C, D, E can be computed ados eqs. (2) through (7) respectively.Fis. 1 shows computed a (dotted curves) as compared with test values of σ (solidcurves). Calculated values differ from test ones by less than 7%.