物理冶金原理金屬學(xué)3合金相圖與凝固

1、Fe9Cr9Si2 s-Phase Reinforced Wear and Corrosion Resistant MaterialsFe9Cr9Si2 s-PhaseCr3SiCr2Ni3Si包晶轉(zhuǎn)變的應(yīng)用：利用胞晶轉(zhuǎn)變特點(diǎn)細(xì)化凝固組織晶粒 L + NiTi NiTi2NiTi2共晶轉(zhuǎn)變 L a + b共析轉(zhuǎn)變 a b + g包晶轉(zhuǎn)變 L + a b 包析轉(zhuǎn)變 a + b g 二元系中的三相平衡F = 2 3 + 1 = 0共晶轉(zhuǎn)變 L a + b共析轉(zhuǎn)變 a b + g包晶轉(zhuǎn)變 L + a b 包析轉(zhuǎn)變 a + b g Cr3SiL36 + (Cr5Si3)27 (CrSi)35Perit

2、ectic Reactionsin Cu-Zn Binary AlloysFe-C二元合金相圖及鋼鐵材料的平衡凝固組織Fe-C Binary Phase Diagram and The Equilibrium Structures of Irons and Steels重要性意義1. 鐵素體：Ferrite The Solid Solution of C in a-Fe (BCC) 0.0218%C2. 奧氏體：Austenite The Solid Solution of C in g-Fe (FCC) 2.11%C3. 滲碳體：Cementite The Iron Carbide Fe3C

3、 6.69%C4. 石墨：Graphite The Stable Form of CarbonFe-C二元合金中的相：Phases in Fe-C Binary AlloysgaFe3C1.胞晶轉(zhuǎn)變Peritectic Reactiond0.09 + L0.53 g0.172.共晶轉(zhuǎn)變Eutectic ReactionL4.33(Fe3C) 6.69 + g 2.11 Ledeburite 萊氏體3.共析轉(zhuǎn)變Eutectoid Reaction0.77 (a 0.0218 + Fe3C) Pearlite 珠光體ES線！GS線！Fe-C相圖中的三相平衡SteelsCast IronsLamel

4、lar Fe3C/Fe Eutectic層片狀萊氏體高碳鋼中的珠光體Pearlite in High Carbon Steel珠光體 OM 、TEMFe-C合金的分類(lèi)：1. 純鐵Pure Iron：2. 鋼Steels: C% 2.11% 亞共析鋼：%C 0.77% 共析鋼: C%= 0.77% 過(guò)共析鋼：0.772.11%C 低碳鋼、中碳鋼、高碳鋼3. 鑄鐵Cast Irons亞共晶鑄鐵共晶鑄鐵過(guò)共晶鑄鐵 白口鑄鐵、灰口鑄鐵亞共析鋼過(guò)共析鋼亞共晶鑄鐵亞共晶鑄鐵胞晶轉(zhuǎn)變Peritectic Reactiond + L0.53 g共晶轉(zhuǎn)變Eutectic ReactionL4.33 (Fe3C)

5、 6.69 + g 2.11共析轉(zhuǎn)變Eutectoid Reactiong 0.77 a 0.0218 + Fe3C胞晶轉(zhuǎn)變Peritectic Reactiond + L0.53 g共晶轉(zhuǎn)變Eutectic ReactionL4.33 (Fe3C) 6.69 + g 2.11共析轉(zhuǎn)變Eutectoid Reactiong 0.77 a 0.0218 + Fe3C胞晶轉(zhuǎn)變Peritectic Reactiond + L0.53 g共晶轉(zhuǎn)變Eutectic ReactionL4.33 (Fe3C) 6.69 + g 2.11共析轉(zhuǎn)變Eutectoid Reactiong 0.77 a 0.021

6、8 + Fe3CPearlite 珠光體Ferrite鐵素體共析鋼的凝固共析鋼組織 珠光體高碳鋼中的珠光體Pearlite in High Carbon Steel過(guò)共析鋼組織：晶界網(wǎng)狀二次滲碳體珠光體過(guò)共析鋼組織：晶界網(wǎng)狀二次滲碳體珠光體亞共晶白口鑄鐵凝固組織 初生奧氏體萊氏體共晶共晶白口鑄鐵凝固組織：片層狀萊氏體共晶Laser Melted Rapidly Solidified Irregular Fe3C/Fe Eutectic 不規(guī)則萊氏體Laser Melted Rapidly Solidified Irregular Fe3C/Fe Eutectic 不規(guī)則萊氏體共晶白口鑄鐵凝固組

7、織：不規(guī)則萊氏體共晶過(guò)共晶白口鑄鐵凝固組織： 片狀初生滲碳體片層狀萊氏體共晶合金性能與合金相圖的關(guān)系一、相圖與合金物理性能 電阻、硬度二、相圖與合金力學(xué)性能 強(qiáng)度、塑性三、相圖與合金加工制造性能 流動(dòng)性、鑄造性能、焊接、熱處理、鍛造三元合金相圖與合金的平衡凝固Ternary Phase DiagramsandEquilibrium Solidification of Ternary AlloysCompositional Triangle of Ternary Phase Diagramoc + oa + ob = A% + B% + C% =100%兩相平衡規(guī)律：Tie Line連接線(直線

8、法則): 確定平衡相之成分點(diǎn)杠桿定律：求出平衡相之重量相對(duì)量 a bf= 3-2+1 = 2a o b二、單相合金的平衡凝固：Equilibrium Solidification 2. 兩相平衡的基本規(guī)則：杠桿規(guī)則 Lever Rule 平衡相之成分點(diǎn)：連接線tie-line or Conode 平衡相之相對(duì)重量百分?jǐn)?shù)：杠桿定律 B%BAT, oCLiquid: LL + aSolid: aCoCLCSWS (CoCs) = WL (CLCo) WS WLCs Co CLLaL+a兩相平衡規(guī)律：連 接 線(直線法則)杠 桿 定 律三相平衡：重心法則abgocbacBAa% = oa/Aa b%

9、 = ob/Aa g% = oc/Aa f= 3-3+1 = 1T1SolidusT1LiquidusT2sT3sT2LT3LLSoCBALaL+a水平（等溫）截面圖的作用：1、存在嚴(yán)格相平衡關(guān)系！2、確定平衡相成分！3、確定平衡相的相對(duì)量（杠桿規(guī)則！重心法則）兩相區(qū)的形狀：兩條相對(duì)直線（連接線）與兩條相對(duì)曲線圍成的四邊形！AoDBVertical Section垂直截面圖LL + aaTLTs垂直截面圖的作用：1、合金狀態(tài)隨溫 度的變化2、確定合金的臨界點(diǎn)注意：1、不存在相平衡關(guān)系！2、不能確定平衡相成分！3、不能用杠桿規(guī)則！DAAoDBFLL + aaTLTs垂直截面圖的作用：1、合金狀態(tài)

10、隨溫 度的變化2、確定合金的臨界點(diǎn)注意：1、不存在相平衡關(guān)系！2、不能確定平衡相成分！3、不能用杠桿規(guī)則！DFNo Phase Equilibrium Relations in Vertical Sections of a Ternary Phase Diagram三元系中的三相平衡Three-Phase Equilibrium in Ternary Alloysf = 3 - 3 + 1 = 1 三相區(qū)空間形狀 (a + b + g):以三平衡相成分隨溫度變化線（單變量線）為棱邊的曲邊三棱柱體連接三角形三相區(qū)空間形狀 (a + b + g):以三平衡相成分隨溫度變化線（單變量線）為棱邊的曲邊

11、三棱柱體abg等溫截面：連接三角形垂直截面：曲邊三角形水平投影圖：直邊三角形abgT1FEa + b + gEFWNiSiNi31Si12Ni3Si(LT)Ni3Si2(LT)NiSi2(LT)WSi2W5Si3Ni4W(LT)2060802080602040W2Ni3Si40(b)W2Ni3SiTungsten dendrite(c)三元系中的四相平衡f = 3 - 4 + 1 = 0adgb四平衡相位于同一平面內(nèi)液相線投影圖與四相平衡反應(yīng)類(lèi)型四相平衡面上相平衡關(guān)系A(chǔ)BA + BLL + BA + L三相區(qū)的空間形狀：以三條成分單變量線為棱邊的三棱柱體連接三角形Tie Triangle四相平

12、衡面A1B1C1與所有11個(gè)相區(qū)相交！液固兩相區(qū)空間形狀三元合金相圖等溫截面圖Isothermal Sections in Ternary Phase Diagrams 存在嚴(yán)格的相平衡關(guān)系確定各平衡相成分預(yù)測(cè)合金平衡組織abgABC兩相區(qū)：兩直線（連接線）、兩曲線圍成！一系列連接線杠桿定律單相區(qū)：多條曲線、直線圍成的不規(guī)則區(qū)域L+A+BL+AL+CL+BLABC三相區(qū)：連接三角形！重心法則！L+A+BL+AL+CL+BLABCL+B+C三相區(qū)：連接三角形！重心法則！L+A+BL+AL+CL+BLABCL+B+CL+A+C三相區(qū)：連接三角形！重心法則！三相區(qū)：連接三角形！重心法則！(A+B)兩

13、相共晶三元合金相圖中的垂直截面圖Vertical Sections in Ternary Phase Diagrams合金狀態(tài)隨溫度的變化確定合金之臨界點(diǎn)制定合金加工制備工藝的基礎(chǔ)LL + aaTLTs垂直截面圖的作用：1、合金狀態(tài)隨溫 度的變化2、確定合金的臨 界點(diǎn)注意：1、不存在相平衡關(guān)系！2、不能確定平衡相成分！3、不能用杠桿規(guī)則！DALL + aaTLTs垂直截面圖的作用：1、合金狀態(tài)隨溫 度的變化2、確定合金的臨 界點(diǎn)注意：1、不存在相平衡關(guān)系！2、不能確定平衡相成分！3、不能用杠桿規(guī)則！DFNo Phase Equilibrium Relations in Vertical Sec

14、tions of a Ternary Phase Diagram三元合金相圖中的水平投影圖與液相面投影圖Horizontal and Liquidus Projections of Ternary Phase Diagrams1可完整分析合金的凝固、固態(tài)相變過(guò)程；2預(yù)測(cè)組織及平衡相成分3計(jì)算合金中平衡相及組織的相對(duì)含量各典型成分點(diǎn)合金的平衡凝固組織組織相對(duì)量計(jì)算：aa LA L(A+C) L(A+B+C)組織中各相及組織相對(duì)量的計(jì)算：直線法則、重心法則合金平衡凝固組織:A+(A+B)+(A+B+C)組織相對(duì)量計(jì)算：A(A+B)(A+B+C)合金的平衡凝固組織:(A+B) + (A+B+C)組織

15、相對(duì)量計(jì)算：(A+B)兩相共晶(A+BC)三相共晶(A+B)兩相共晶(A+BC)三相共晶合金平衡凝固組織:A + (A+B+C)組織相對(duì)量計(jì)算：初生A樹(shù)枝晶枝晶間(A+B+C)三相共晶枝晶間少量(A+B) 共晶液相面線投影圖中各種四相平衡轉(zhuǎn)變L+S=(T + a-Al)L+Q=(S+T)L=(b+T+a-Al)Mo2Ni3SiL+Mo2Ni3SiMo2Ni3SiMo2Ni3SiNiL+Lg-Mo2Ni3Si相區(qū)垂直截面圖液相線投影圖與四相平衡反應(yīng)類(lèi)型四相平衡面上相平衡關(guān)系Unidirectional Solidification ProcessingDendritic Front Solidi

16、ficationSolidification DirectionSolidification DirectionPreferred Orientation of Crystal Growth晶體生長(zhǎng)過(guò)程中的擇優(yōu)取向性e.g.立方系金屬擇優(yōu)生長(zhǎng)方向: 晶向Preferred Orientation and Competitive Growth of Crystal Growth Competitive Growth Induced Natural Selection of Columnar Grains(Struggles for existance, the Fittest Survives!

17、)Exothermic-Mould Unidirectional Solidification Method 鑄型發(fā)熱保溫定向凝固法定向凝固技術(shù)及定向凝固柱晶高溫合金航空發(fā)動(dòng)機(jī)葉片Directionally Solidified Columnar Grain Turbine Blades with or without TBCsProduction of Single-Crystal Turbine Blades by DS Solidification Only one crystal survives in the neck as result of Competition GrowthS

18、olidification DirectionMo2Ni3SiL+Mo2Ni3SiMo2Ni3SiMo2Ni3SiNiL+Lg-Mo2Ni3Si相區(qū)垂直截面圖Rapid Solidification Processing for Rapidly Solidified Non-Equilibrium AlloysHua-Ming WangLaboratory of Laser Materials Processing and Surface EngineeringBeijing University of Aeronautics and Astronautics北京航空航天大學(xué)激光材料加工與表面

19、工程實(shí)驗(yàn)室Importance of Solidification Processing to MetalsGrain Size, DAS, Eutectic Spacing and Colony SizeChemical Homogeneity and Solidification Micro- and Macro-SegregationPhase Selection, Morphologies and DistributionsChemical and Physical Properties Processing Properties (Heat Treating, Forging, We

20、lding, etc) Why Rapid Solidification?Coarse-Grained As-Cast Structure Low Strength; Low Ductility and Toughness; Worsen Processing Capability;Severe Shrinkage and PorositySerious Micro and Macro Segregation Alloying Ineffective or Defective Homogenization Difficult or Impossible Precipitation of Low

21、-Melting-Point Eutectics or Harmful Phases Secondary Processing Difficult or Impossible Unique Effects of Rapid Solidification on Solidification MicrostructureRefinement of Grain Size and Microstructure (PDAS, SDAS, Eutectic Colony Size and Spacing, Porosity, etc)Suppression of Solidification Segreg

22、ation Extension of Solubility Limits Formation of New Metastable and Quasi-Crystalline PhasesFormation of Amorphous Phases (Metallic Glass)Rapidly Solidified Non-Equilibrium New MaterialsStructural FunctionalRapidly Solidified Microcrystalline MaterialsRapidly Solidified Metastable MaterialsRapidly Solidified Qausi-Crystalline MaterialsRapidly Solidified Amorphous Alloys or Metallic Glass Rapidly So