現(xiàn)代塑性變形物理學(xué)5

1、Lecture 5：Texture and Quantative AnalysisTheory Physical Based Plastic DeformationJianguo TXinming Z1 Texture and ODFCrystallographic texture is defined as the preferred alignment of the crystallographic orientations in a polycrystalline medium. dVV f (g)dgOrientation Distribution Function (ODF)1 Te

2、xture and ODF Orientation Distribution Function (ODF) is a central concept in texture analysis and anisotropy. Probability distribution in whatever space is used to parameterize orientation, i.e. a function of three variables, e.g. 3 Euler angles f(f1,F,f2). f 0 (very important!). Probability of fin

3、ding a given orientation (specified by all 3 parameters) is given by f. 1 Texture and ODF Textures can also be developed, strengthened or weakened as a result of heat treatment due to recrystallization- nucleation and grain growth (Recrystallization Texture) large plastic deformation (forming proces

4、ses.) resuling in Deformation Textures1 Texture and ODF Texture Representation is the Major problem! Typical representation: Cartesian plot (orthogonal axes) of the intensity in Euler angle space. Unfortunate choice: Euler angles are inherently spherical (globe analogy). Recall the Area/Volume eleme

5、nt: points near the origin are distorted (too large area).1 Texture and ODF21F1 Texture and ODF Crystal Symmetry and Sample Symmetry have great importance on ODF.Crystal Symmetry Elemente.g. rotation on 001(associated with f2)1 Texture and ODF21F21T100010001MeMT1 Texture and ODFEE0010001000100,2NDL2

6、2LE100010001,2RDL1 Texture and ODF2 ODF from PFNS1P1P2S2S2O2 ODF from PFn 2dsindhklah2 k2 l22 ODF from PF1 入射線，2 樣品，3 衍射線，4 記數(shù)器2 ODF from PF,dIpd 2 ODF from PF,gg ,f gf 220011,22pf g dfd 2 ODF from PF2 ODF from PF2 ODF from PFPole Figure can be expanded with following series:2 ODF from PF lllf gCTgODF can be expanded with following series: 21cosiillTgePeF2 ODF from PF2 ODF from PF3. Quantitative texture analysisf(g)g3. Quantitative texture analysis晶體對(duì)稱(chēng)性對(duì)f(g)3. Quantitative texture analysis3. Quantitative texture analysis3. Quantitati