課件工程材料學2015

1、Engineering MaterialsSun Lan School of Manufacturing Science and Engineering, Sichuan University Sun Lan（孫蘭）Dept. of Materials Forming and ControllingSchool of Manufacturing Science and EngineeringSichuan UniversityTel: E-mail: 3Course Description Engineering Materials ： the materials science, gener

2、al laws on the material composition, structure, performance and applications Course requires ：the relationship on composition, structure and performance of the commonly used engineering materialsThe types, grades, properties and uses of engineering materials.the correct choice of heat treatment meth

3、odThe failure of the different material components4Learning MethodThe failureform of materialsMaterial composition and performance requirementsThe preparation of materials、Materialof alloy45Course Features Technical coursesStronger NarrativeConcept of the principleMore Symbol Less Calculation Strong

4、er practicalityPreviewReview Attendance66References1、工程材料學（第1版或第2版-修訂版） 王曉敏 哈工大出版社（2002年8月）2、Engineering Materials ( Vol. One, 2nd Edition ) R. L. Timings 世界圖書出版公司 （2000年6月）3、機械工程材料 （第1版） 沈 蓮 機械工業(yè)出版社 （1999年5月）4、Selection and Use of Engineering Materials ( 3rd Edition ) J. A. Charles, F. A. A. Crane,

5、 J. A. G. Funess 世界圖書出版公司（2000年6月） Chapter 1 Introduction to Materials and their PropertiesChapter 1 Introduction to Materials and Their Propertiesthe selection of materials for any given application. The basic properties of materials. The grouping of materials into their main categories.1.1 Introdu

6、ctionto use and to develop materials to satisfy the human requirementsmaterials for housing, heating, furniture, clothes, transportation, entertainment, medical care, defense, etc.waste materials must be reclaimed and recycledrole of materials engineers ( also students )10Mainstay industry： Material

7、 is the basis of any forms of energy and informationEngineering Materials：structural materials，the mechanical properties，engineering structures and mechanical parts as the main requirements.1.1 Introduction1.2 Selection of MaterialsCommercial factors such as: (a) cost (b) availability (c) ease of ma

8、nufactureEngineering properties of materials such as:electrical conductivity strength, toughness corrosion resistance, wear resistanceease of forming by extrusion, forging and casting machinability heat (thermal ) resistance, etc. 121.2 Selection of MaterialsExamples : (a) electric cable connectorel

9、ectrical conductivity, ease of forming by extrusion, forging and casting, ease of machinability, adequate strength and corrosion resistance.Silver? (Expensive) Cu, Al (b) connecting rodStrength, toughness, ease of machinability (c) tailstock casting (底座鑄件)-cast ironadequate strength， ease of melting

10、 and casting， good machinability13131.3 Material Properties（1）使用性能Application properties ： mechanical properties，physical properties and chemical properties（Priority）（2）工藝性能Processing properties ：鑄造(Casting)、鍛壓(Forging and pressing)、焊接(Welding)、熱處理(Heat treating)和切削(Cutting)性能等。1414Mechanical proper

11、ties:（ Strength, stiffness, hardness, elasticity, plasticity, toughness and wear resistance）Deformation: changes of the shape and size because of the external forces.elastic deformation。plastic deformation。1.3 Material Properties1515StrengthResistance of plastic deformation and fractureYield strengt

12、h: stress happened plastic deformationTensile strength and bending strength: stress happened fractureApplication：machine components，1.3 Material Properties1616PlasticCharacterization of plastic deformation under external forceFractured residual deformation： Elongation percentage：Contraction of area：

13、1.3 Material Properties17韌性ToughnessAbsorb energy before fracture, and the ability to plastic deformation（Strength + Plastic） 剛度(stiffness )Resistance of elastic deformationThe elastic modulus E: stress/strain, a constant in the range of elastic deformation; the key performance indicators for the ch

14、aracterization of material stiffness.1.3 Material Properties18Hardness: the materials resistance to localized plastic deformation. （HRC、HB、HV）.Wear resistance: the material to resist wear under certain operating conditions.The relative wear resistance is the ratio of the amount of wear of two materi

15、als in the same working conditions.1.3 Material Properties19材料的力學性能指標應用剛度：剛度設計中，考慮構(gòu)件在受力時發(fā)生的彈性變形量。彈性模量。如精密機床主軸等零構(gòu)件彈性指標：彈性極限和彈性模量是設計彈性零件考慮的性能指標。如汽車板簧和各類彈簧等屈服強度和塑性：一般零件的抗斷裂設計。硬度：在耐磨零件中必須考慮的性能指標。如滾珠軸承、刀具等.20TITANIC2121Impacting tests results of steel on Titanic （Left）and steel used on board recently（Rig

16、ht）22Physical property density、Melting point、Heat conductivity、Electrical conductivity、Thermal expansion、Magnetism；Chemical propertyresistance to chemical erosion of various media. (Oxidation resistance and corrosion resistance)1.3 Material Properties2323(2) Processing properties casting、forging、wel

17、ding、heat treating and cutting.Casting（ Fluidity, shrinkage, segregation ）cast aluminum (copper) alloy cast iron cast steel1.3 Material Properties24Forging properties （塑性、變形抗力） Low carbon steel Medium carbon steel（ Low alloy steel ）High carbon steel（ High alloy steel ） cast iron 不可鍛壓Welding properti

18、es （可焊性、焊后開裂的傾向、焊區(qū)硬度） Low carbon steel Medium carbon steel（ Low alloy steel ）High carbon steel（ High alloy steel ） aluminum (copper) alloy 1.3 Material Properties25Heat treating難易程度及產(chǎn)生缺陷的傾向 Only change the internal structure, not change the shape, to achieve different mechanical properties.Cutting切削

19、難易程度、加工表面質(zhì)量 Grey cast iron: excellent machinability(切削加工性). cabon steel(碳鋼 ) high alloy steel(高合金鋼)1.3 Material Properties2626Common form of failure in engineering ：1、變形(Deformation)：Plastic deformation occurs彈簧2、斷裂(Fracture)：Destructive damage or failure軸3、磨損(Wear)：No large deformation and fracture

20、刀具4、腐蝕(Corrosion)：Severe corrosion causes the structural integrity damage鋼鐵生銹1.3 Material Properties271.4.1 Metal materials以金屬鍵結(jié)合為主 良好的導電性、導熱性、延展性和金屬光澤 用量最大、應用最廣泛黑色金屬(Ferrous metal)有色金屬(Nonferrous metal)輕金屬,重金屬,貴金屬,稀有金屬 1.4 Engineering materials28(1)Ferrous metal1.4 Engineering materials * Plain car

21、bon steels * Alloy steels * Cast irons * Wrought iron29(1)Ferrous metal1.4 Engineering materialsCarbon Steel： Basic elements：Fe, C (compounds) (0.02-2.11%)Impurities：S, P, Mn, SiAlloy Steel:Carbon steel + alloying elements (Mn, Ni, Cr, Mo, V, W, Ti)30(1)Ferrous metal1.4 Engineering materialsCast Iro

22、n: C%1.7%, greater impurities (S, P, Mn, Si) Carbon compounds + Free carbon Grey cast iron, White cast iron, Melleable cast iron and Alloying cast iron Low melting temperature, Good fluidity熟鐵（Wrought Iron ）: Nearly pure iron, C%0.02 Extreme toughness, low strength31(2) Non-ferrous metalCopper alloy

23、s：青銅Bronze ( copper and tin )，黃銅Brass ( copper and zinc )Aluminum alloysTitanium alloys1.4 Engineering materials32(3) Non-metallic materials工程塑料(Engineering Plastics)：聚酰胺、尼龍、等。工業(yè)陶瓷(Industrial Ceramics )：普通陶瓷、特種陶瓷等。復合材料(Composite Material )：玻璃纖維樹脂基復合材料、 層合復合材料。1.4 Engineering materials1.5 Composite m

24、aterials ( Composites )是把兩種或兩種以上不同性質(zhì)或不同結(jié)構(gòu)的材料以微觀或宏觀的形式組合在一起而形成的材料。Reinforcement （增強體）Matrix （基體）Kinds of Composites * Metal Matrix Composite(s) ( MMC or MMCs ) * Polymeric Matrix Composite(s) ( PMC or PMCs ) * Ceramic Matrix Composite(s) ( CMC or CMCs)1.6 Factors affecting materials propertiesHeat tr

25、eatmentProcessing * cold-working （形變強化） * hot-working ( recrystallisation 再結(jié)晶)Environmental reactions * dezincification of brass（黃銅脫鋅） * rusting of steel and iron （鋼鐵生銹） * degradation of plastics （塑料降解）351.7 Relations of composition, structure and properties Composition Structure Properties 化學成分和組織結(jié)

26、構(gòu)是其力學性能的內(nèi)部依據(jù)；力學性能是具有一定化學成分和組織結(jié)構(gòu)的外部表現(xiàn)。 Based on the iron carbon phase diagram, carbon content increasing, phase change and mechanical properties change.36（1）結(jié)構(gòu)（structure） 組成相（phase）的原子結(jié)構(gòu)和晶體結(jié)構(gòu)（2）組織（microstructure） 顯微組織、晶體缺陷、冶金缺陷，等 microstructure: phase（相）、content（組元） lattice dislocation: 點、線、面缺陷 metal

27、lurgy inclusions: 渣、夾雜、氣體，（3）晶體與非晶體 crystal materials: lattice structure amorphous materials: without certain structure1.7 Relations of composition, structure and properties37When the chemical composition of steel is a constant, different process (heat treatment, cold /thermoplastic processing) can

28、change its structure, and performance;Other factor：metallurgical quality(冶金質(zhì)量)（The quality can be control through the smelting, casting, rolling or forging process.）1.7 Relations of composition, structure and properties 381.8 Development trend of engineering materials 21世紀初期，金屬材料在工程材料中仍將占主導地位，其中鋼鐵仍是產(chǎn)量最大、覆蓋面最廣的工程材料，但非金屬材料和復合材料的發(fā)展會更加迅速。 今后材料發(fā)展的總趨勢是：以高性能和可持續(xù)發(fā)展為目標的傳統(tǒng)材料的改造及以高度集成化、微細化和復合化為特征的新一代材料的開發(fā)。39（1）生產(chǎn)工藝的完善和