JMatPro計算原理探討.ppt

1、JMatPro計算原理探討,動態(tài)物理模型的建立 強大的金屬材料數(shù)據(jù)庫 廣泛且經(jīng)實驗驗證的計算結(jié)果,Modelling properties and behaviour: JMatPro 材料性能模擬： JMatPro,3.1 Thermodynamic Calculations: Background 熱動力學計算原理,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 純組元的吉布斯自由能,Ideal

2、entropy 理想狀態(tài)下的焓,Interaction terms(Based on pairwise interactions) 相互作用項（基于兩兩之間相互作用）,3.2 Phase Transformation Kinetics:Model 相轉(zhuǎn)變動力學模型:(用于鋼的),General Equation for TTT calculation is after Kirkaldy et al. (TTT計算的一般方程： 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, 是一個經(jīng)驗系數(shù)，G是晶粒尺寸，D是有效擴散系數(shù)， T 是過冷度， q 是一個取決于有效擴散機制的指數(shù)。 X是轉(zhuǎn)變的百分數(shù)),3.2. 1 Martensitic transformations 馬氏體轉(zhuǎn)變,3.2.2 Phase Transfor

4、mations (TTT/CCT diagrams) 相轉(zhuǎn)變（TTT/CCT相圖）,Calculated TTT diagrams for U720 and U720LI with experimental results of Keefe et al. superimposed.,對U720 和 U720LI 所計算的TTT曲線與Keefe et al. 的實驗結(jié)果比較,3.2.3 Phase Transformations (g/gcoarsening) 相轉(zhuǎn)變（ /晶粒的長大 ）,晶粒的計算長大率與實驗得到的長大率的比較,3.2.2 Phase Transformations (TTT/

5、CCT diagrams) 相轉(zhuǎn)變（TTT/CCT相圖）,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) 相轉(zhuǎn)變（TTT/CCT相圖）,RR2071合金計算的TTT曲線與Rae at al.的實驗結(jié)果的比較,3.3 Background to Property Calculations 物理/熱物理性能計算背景知識,Pr

6、operty of a Solution Phase 固溶相性能,Property of pure components 純組元時的性能,Interaction terms(Based on pairwise interactions) 相互作用項（基于相與相兩兩之間相互作用）,3.4 Mechanical Properties 機械性能,Two types of strengthening mechanism are treated. 可考慮兩種強化機制 Solid solution strengthening. 固溶強化 Particle strengthening. 第二相粒子強化,3.

7、4.1 Mechanical Properties (Precipitation Hardening) 機械性能（析出強化）,The yield strength of an alloy hardened by g particles can be given by the equation below for small particles 微小粒子對合金的屈服強度的強化效果可用以下方程來衡量,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 = 晶格屈服強度和合金屈服強度 M = 泰勒系數(shù) b = 柏氏矢量 A = 形狀因子常量 d = 析出粒子直徑 = 位錯的線張力 f = 體積分數(shù) = APB 能量,For larger particles the equation below can be used 對于大尺寸的粒子，強化效果用下面方程來衡量, = constant that accounts for repulsi

9、on of dislocations within the precipitates (essentially an empirically adjustable parameter). =一個表明析出物內(nèi)部位錯間斥力的常數(shù)（實質(zhì)上是一個經(jīng)驗系數(shù)）,3.4.1 Mechanical Properties (Precipitation Hardening) 機械性能（析出強化）,3.4.2 Mechanical Properties 機械性能,屈服強度的計算值與實驗值的比較,3.4.3 Comparison of Mechanical Properties for Ni-based Supera

10、lloys 鎳基超合金機械性能實驗與計算值的比較,3.4.4 Ageing Response of a Ni-based Superalloy (combining coarsening and pptn hardening) 鎳基超合金時效效應(yīng)（綜合晶粒長大和析出強化）,3.5 High Temp Mechanical Properties (creep)高溫機械性能（蠕變）,General Creep Equation蠕變一般方程,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 = 材料常數(shù) D = 有效擴散系數(shù) SFE = 層錯能 G = 剪切模量 b = 柏氏矢量 = 外加應(yīng)力 o = 背應(yīng)力 E = 楊氏模量 m = 3n = 蠕變指數(shù),3.5.1 High Temp Mechanical Properties (creep)高溫機械性能（蠕變）,蠕變率的計算值與實驗值的比較,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 在許多實際情況中，斷裂強度是一個可供選擇的設(shè)計標準。我們的軟件現(xiàn)在已經(jīng)能夠計算蠕變強度，這是通過利用蠕變斷裂應(yīng)力與蠕變率的對立關(guān)系間接得到的。,3.5.2 High Temp Mechanica

13、l Properties (creep)高溫機械性能（蠕變）,Comparison between experimental and calculated 1000hr rupture strengths for various wrought Ni-based superalloys,3.5.3 High Temp Mechanical Properties (creep)高溫機械性能（蠕變）,成分不同的各種鎳基超合金1000小時斷裂強度實驗值與計算值的比較。,Comparison between experimental and calculated rupture life for va

14、rious single crystal superalloys,3.5.4 High Temp Mechanical Properties (creep)高溫機械性能（蠕變）,各種單晶超合金斷裂壽命的實驗值與計算值的比較。,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. 蠕變計算已經(jīng)綜合了早期低溫

15、屈服應(yīng)力計算，用來模擬鎳基超合金隨溫度升高時的流體應(yīng)力。,3.6 High Temp Mechanical Properties 高溫機械性能,The decay in RT yield stress with is well matched using an equation of the following type 高溫情況下，室溫屈服應(yīng)力的衰減與下面方程所給出的結(jié)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 高溫機械性能,在這里，和 都是與室溫強度RT 和激活能Q值直接相關(guān)的常量。Q值的大小一般是通過回歸分析憑經(jīng)驗來確定的。,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. 當溫度升到較高的檢測溫度下，試驗機的拉伸速率等于或小于蠕變速率時，合金將發(fā)生蠕變屈服。 This can be combined with the previous relationship,3.6 High Temp Mechanical Properties 高溫機械性能,to give mechanical properties from RT to the melting point 把蠕變效應(yīng)和其它因素結(jié)合起來，這樣我們就可以給出從室溫到材料熔點區(qū)間范圍內(nèi)材料的機械性能。,Comparison between experimental and calculated yield stress for Nimonic 75 and 105 as a function of temperature.,3.6 High Temp Mechanical Properties 高溫機械性能,75和105鎳基合金實驗與計算情況下強度隨溫度的變化的比較,Comparison between experimental and calculated yield stress