JMatPro计算原理探讨.ppt

1、JMatPro计算原理探讨,动态物理模型的建立 强大的金属材料数据库 广泛且经实验验证的计算结果,Modelling properties and behaviour: JMatPro 材料性能模拟： JMatPro,3.1 Thermodynamic Calculations: Background 热动力学计算原理,Basic equation for the Gibbs Energy of a multi-component Solution Phase 多元合金固溶相吉布斯自由能基本方程,Gibbs energy of pure components 纯组元的吉布斯自由能,Ideal

2、entropy 理想状态下的焓,Interaction terms(Based on pairwise interactions) 相互作用项（基于两两之间相互作用）,3.2 Phase Transformation Kinetics:Model 相转变动力学模型:(用于钢的),General Equation for TTT calculation is after Kirkaldy et al. (TTT计算的一般方程： Kirkaldy et al.), = 2(G-1)/2, is an empirical coefficient, G is the ASTM grain size,

3、D is an effective diffusion coefficient, T is the undercooling, q is an exponent,dependent on the effective diffusion mechanism and x is the fraction transformed. ( = 2(G-1)/2, 是一个经验系数，G是晶粒尺寸，D是有效扩散系数， T 是过冷度， q 是一个取决于有效扩散机制的指数。 X是转变的百分数),3.2. 1 Martensitic transformations 马氏体转变,3.2.2 Phase Transfor

4、mations (TTT/CCT diagrams) 相转变（TTT/CCT相图）,Calculated TTT diagrams for U720 and U720LI with experimental results of Keefe et al. superimposed.,对U720 和 U720LI 所计算的TTT曲线与Keefe et al. 的实验结果比较,3.2.3 Phase Transformations (g/gcoarsening) 相转变（ /晶粒的长大 ）,晶粒的计算长大率与实验得到的长大率的比较,3.2.2 Phase Transformations (TTT/

5、CCT diagrams) 相转变（TTT/CCT相图）,718,Calculated TTT diagram for the single crystal alloy RR2071 with experimental results of Rae at al. superimposed,3.2.2 Phase Transformations (TTT/CCT diagrams) 相转变（TTT/CCT相图）,RR2071合金计算的TTT曲线与Rae at al.的实验结果的比较,3.3 Background to Property Calculations 物理/热物理性能计算背景知识,Pr

6、operty of a Solution Phase 固溶相性能,Property of pure components 纯组元时的性能,Interaction terms(Based on pairwise interactions) 相互作用项（基于相与相两两之间相互作用）,3.4 Mechanical Properties 机械性能,Two types of strengthening mechanism are treated. 可考虑两种强化机制 Solid solution strengthening. 固溶强化 Particle strengthening. 第二相粒子强化,3.

7、4.1 Mechanical Properties (Precipitation Hardening) 机械性能（析出强化）,The yield strength of an alloy hardened by g particles can be given by the equation below for small particles 微小粒子对合金的屈服强度的强化效果可用以下方程来衡量,YS0 and YS1 = yield stress of the matrix and alloy M = Taylor factorb = burgers vector,A = shape dep

8、endent constant d = ppt. diameter = line tension of a dislocation f = vol fraction = APB energy YS0 和 YS1 = 晶格屈服强度和合金屈服强度 M = 泰勒系数 b = 柏氏矢量 A = 形状因子常量 d = 析出粒子直径 = 位错的线张力 f = 体积分数 = APB 能量,For larger particles the equation below can be used 对于大尺寸的粒子，强化效果用下面方程来衡量, = constant that accounts for repulsi

9、on of dislocations within the precipitates (essentially an empirically adjustable parameter). =一个表明析出物内部位错间斥力的常数（实质上是一个经验系数）,3.4.1 Mechanical Properties (Precipitation Hardening) 机械性能（析出强化）,3.4.2 Mechanical Properties 机械性能,屈服强度的计算值与实验值的比较,3.4.3 Comparison of Mechanical Properties for Ni-based Supera

10、lloys 镍基超合金机械性能实验与计算值的比较,3.4.4 Ageing Response of a Ni-based Superalloy (combining coarsening and pptn hardening) 镍基超合金时效效应（综合晶粒长大和析出强化）,3.5 High Temp Mechanical Properties (creep)高温机械性能（蠕变）,General Creep Equation蠕变一般方程,A = Material constant D = effective diffusion coeff SFE = stacking fault energyG

11、 = shear modulus b = burgers vector = applied stress o = back stressE = Youngs modulus m = 3n = creep exponent,A = 材料常数 D = 有效扩散系数 SFE = 层错能 G = 剪切模量 b = 柏氏矢量 = 外加应力 o = 背应力 E = 杨氏模量 m = 3n = 蠕变指数,3.5.1 High Temp Mechanical Properties (creep)高温机械性能（蠕变）,蠕变率的计算值与实验值的比较,As rupture strength is an altern

12、ative design criterion in many practical cases, the calculation procedure has been extended to include this property by using an inverse relationship between stress rupture life and secondary creep rate 在许多实际情况中，断裂强度是一个可供选择的设计标准。我们的软件现在已经能够计算蠕变强度，这是通过利用蠕变断裂应力与蠕变率的对立关系间接得到的。,3.5.2 High Temp Mechanica

13、l Properties (creep)高温机械性能（蠕变）,Comparison between experimental and calculated 1000hr rupture strengths for various wrought Ni-based superalloys,3.5.3 High Temp Mechanical Properties (creep)高温机械性能（蠕变）,成分不同的各种镍基超合金1000小时断裂强度实验值与计算值的比较。,Comparison between experimental and calculated rupture life for va

14、rious single crystal superalloys,3.5.4 High Temp Mechanical Properties (creep)高温机械性能（蠕变）,各种单晶超合金断裂寿命的实验值与计算值的比较。,The creep calculations have been combined with the earlier low temperature yield stress calculations to model the flow stress of Ni-based superalloys at raised temperatures. 蠕变计算已经综合了早期低温

15、屈服应力计算，用来模拟镍基超合金随温度升高时的流体应力。,3.6 High Temp Mechanical Properties 高温机械性能,The decay in RT yield stress with is well matched using an equation of the following type 高温情况下，室温屈服应力的衰减与下面方程所给出的结果相吻合。,where and are constants directly related to RT and the value of Q, which is determined empirically through

16、regression analysis.,3.6 High Temp Mechanical Properties 高温机械性能,在这里，和 都是与室温强度RT 和激活能Q值直接相关的常量。Q值的大小一般是通过回归分析凭经验来确定的。,As the temperature is raised to high levels the alloy will yield via creep when the strain rate of the mechanical test is equal to or slower than the creep rate at the testing tempera

17、ture. 当温度升到较高的检测温度下，试验机的拉伸速率等于或小于蠕变速率时，合金将发生蠕变屈服。 This can be combined with the previous relationship,3.6 High Temp Mechanical Properties 高温机械性能,to give mechanical properties from RT to the melting point 把蠕变效应和其它因素结合起来，这样我们就可以给出从室温到材料熔点区间范围内材料的机械性能。,Comparison between experimental and calculated yield stress for Nimonic 75 and 105 as a function of temperature.,3.6 High Temp Mechanical Properties 高温机械性能,75和105镍基合金实验与计算情况下强度随温度的变化的比较,Comparison between experimental and calculated yield stress