粉末冶金1粉末的制备(1)

第1部分 粉末的制备（1）Powder Metallurgy PrincipleRuan Jianming Powder Metallurgy Research Institute 2007Particle Science and Engineering粉末冶金原理(课程分布) 40学时教学方式: 双语讲学 Chinese/English课程内容: Part I Powder fabrication 粉体制备 Part Powder characterization 性能 How do the powders fabricate？ Main methods to fabricate powders What physio-chemical phenomenon could be observed during powder fabrication？Which method is suitable to sphere particles？ How about the particle morphologies？How can we obtain the high purity？What takes place during the powder fabri.?Which condition to control the particle size?What can we do? related powder makings.Continuers What are the microstructures of the particles?What is the apparent density of the powders? Which equipment can measure the fine particles?课时安排 Talking arrangements 序言 Introduction 2hrsPart粉末制备 28hrs 机械研磨 Mechanical grinding 4hrs 雾化制粉 Atomization 4hrs 快速冷凝 RST Rapid solidification 4hrs 化学沉积 Chemistry precipitation 4hrs 电解制粉 Electrical fabrication 4hrs 还原制粉 Reduction 8hrsPart Powder Characterization 12hrs 颗粒结构 Particle microstructure 4hrs 粒度分布 Particle size and distribution 4hrs 比表面 Specific surface 2hrs 考试 Testing 2hrs (close book) 参考书籍:References Powder Metallurgy Science 粉末冶金原理 黄培云 P/M. Principle考核成绩 Score 作业30% 卷面考试70%What is Powder MetallurgyPowder metallurgy Study of the processing of metal powders, including the fabrication, characterization, and conversion of metal powders into useful engineering components.Study of the basic laws and mechanisms of powder fabri., powder compaction, sintering and surface treatments.R&D of novel materials and products.Powder Metallurgy ProcessingReasons for using powder metallurgyThe future of powder metallurgyA comparison of the relative production for some common metal powders, logarithmic scale. Further considerations 1High volume production of precise, high quality structural parts from ferrous alloys;Consolidation of high performance materials, where full density and reliability are primary concerns;Fabrication of difficulty to process materials, where fully dense high performance alloys can be fabricated with uniform microstructure; Further considerations 2Economic consolidation of specially alloys, typically composites containing mixed phase;Synthesis of non equilibrium materials such as amorphous, microcrystalline, or some special alloys;Processing of complex parts with unique ingredients (组元）or uncommon shapes.粉末冶金发展 History and development of P/M 历史部分: 武器, 生活用具, 艺术建筑Weapon, life facilities, arts-construction, etc. 现代部分: 硬质合金, 高温材料, 汽车部件, 军事工程Cement carbide, refractory materials, automobile parts, equipments in defensive, civilization products, etc.目前, 粉末冶金最发达的国家瑞典(Sweden)硬质合金工业非常发达Hoganess, 建立许多子公司, Be number one 其次是北美(North American)和西欧(western European) 。德国的粉末冶金工业也是处于世界前列-工具钢., tooling steel.美国的粉末冶金公司主要产品用户是汽车制造商producer，汽车工业auto vehicle industry发达，带动了美国的粉末冶金工业发展，这是因为发达的汽车工业，大量a huge of application 用粉末冶金部件。Same to American，日本Japan的汽车工业的发展带动了粉末冶金工业发展。Different to China与中国不一样，the western countries and Japan西方或日本的粉末冶金工业是由两部分构成 conbined by two part制粉公司：制备各种粉末：Companies to fabricate and supply powders制品公司：买进粉末，制备零部件： Companies to fabricate final parts 粉末冶金技术的优越性与局限性 advantages and limitation能够大量节约材料、low cast无切削、less cuting少切削，普通铸造合金切削量在30-50%，粉末冶金产品可少于5%。Less or absent cutting machining. “Net shaping”能够大量节省能源 energy saving能够大量节省劳动 labor saving能够制备其他方法不能制备的材料 specific materials and/or products 能够制备其他方法难以生产的零部件 the material and part that are difficultly to be produced by other methods 粉末冶金的特点 particularly points 能生产用普通熔炼方法无法生产的具有特殊性能的材料；ability to produce materials which can not be produced by other method. Porous materials and products, parts within lubricantsRefractory metals such as tungsten, molybdenum, etcPesudo-alloys, such as, tungsten-copper alloysComposite materials, such as 316 ss + bioceramicNano-crystalline, sub-micrometer crystalline grain metalSpecial functional materials and products, such as magnetic products, supper alloys applied in airo-industry. Powder metallurgy disadvantages and limitationRather lower mechanical properties, for their pores in partsSize and morphological limitation, for press machine.Rather lower wrought properties, for the products may contain oxide that induce materials brittle.Rather small industry background compared with casting and conventional materials industry, such iron and steel produced on big scale. 1+12, new materials and high performancePowder metallurgy plus conventional material processing 粉末冶金新技术 Novel techniques of powder metallurgy 快速原形制备技术, RSP粉末注射成形、PIM快速冷凝技术获得非晶粉末、RST粉末溅射成形、powder spray forming机械合金化技术、MA 温压成形技术, Worm Comp.纳米粉末技术, Namo-Tech等静压成形-烧结技术, ISP-sintering 高性能材料研发，等等.A Interest ComparisonMetal powders: 109 kg/yearIndustry minerals: 300 times 109 kg/yearCoffee, tea, and tobacco: 1010 kg/yearPowder metallurgy is a prolonged growth phase;Iron and steel, aluminum, copper, nickel, and tungsten are the main consumption, worldwide. Automobile industry Gear partsMechanical industryP/M Industry 2005 粉末冶金未来 The future of the powder metllurgy 1）铁基结构合金的高精度high precise高质量high quality大数量产品。2）致密高性能材料，主要是理想的密度和牢固性full density and reliability。 3）难加工材料的制造，difficulty to process materials全密度具有统一微观结构的高性能合金。 4）特殊合金，主要为包含有多相的组分multi-composites containing mixed phase，通过增强密度的工艺来制造。These will often be fabricated by enhanced densification.5）非平衡nonequilibrium材料的合成例如such s amorphous非晶，micro-crystalline, or metastable alloys微晶和亚稳合金。 6）具有独特组分或不常用形状的特殊附件的工艺。 Copper and Copper base powder in North AmericaCopper and copper-base powder in 2004 increased 11.3% and copper powder base parts increased 7%.International iron and steel powder Metal powder in 2004 increased by 6.5% to 527,918(mt), figure Iron powder increased 7% over 2003 to 430,119mt. International copper and copper base powders in 2004P/M parts content in a typical vehicleNorth America copper and copper base powderStainless steel powder increased 5% to an estimated 8,488 mt. Tungsten powder increased 16% to 3,177 mt and tungsten carbide powder increased almost 12%.Although there are about 10 companies making aluminum P/M parts, two players dominated the market in North America.European iron and steel powder in 2004 fared better than North America, increasing by 8.8% to 172,952mt.Increases in iron powder in Japan did not match North America.Estimate that that the iron powder market now exceeds 908，000mt Impact of China In the last several years, China poses both a competitive threat and potentially huge opportunity.It has an estimated 680 P/M part makers, but only about five of these are considered capable of making high quality P/M parts.The Chinese P/M parts industry is experiencing an estimated 19% annual growth rate.The typical passenger car in China contains about 4.7kg of P/M parts.China produced about 85000mt of P/M parts.Chinese P/M industry will undoubtedly increase its quality capability as more funds are invested, particularly by Western companies. Currently more than 20 non-Chinese firms representing the U.S, Europe, Japan, Korea, and Taiwan have P/M plants in China mainland. On the other hand, China is beginning to impact the European automotive market, selling inexpensive cars. Chapter 2 粉末制备方法 Powder fabrication methods 1 物理机械法 Physio-Mechanical Protocol1.1 机械研磨法制备粉末 Milling 1.2 高温雾化法制备粉末 Atomization2 物理化学法制备粉末2.1 氧化物还原法制备粉末 reduction of metallic oxides2.2 气相沉积法制备粉末 precipitation from atmosphere phase2.3 液相沉积法制备粉末 precipitation from liquid phase2.4 电解法制备粉末 electrolytic fabrication techniques from the electrode2.5 纳米及超细粉末制备技术 nano/ultro fine powder preparation从过程的实质来看，大体上可以归纳为两大类，即物理机械法mechanical 和物理化学physio-chemical 法粉末的生产方法很多，从工业规模industrial scale而言，应用最广泛pervasive used method的是还原法reducing、雾化