现代粉末冶金技术概述.pptx

现代粉末冶金技术;;;PM Production of notch segment （槽型件）for truck transmission ;;;;;;Nickel Silver Gears, Cams and Pawls：P/M parts used in a fire alarm box density ： 8.0g/cm3, tensile strength： 234MPa, yield strength：138MPa， hardness ：90HRH. a 50% cost savings compared to the prior methods of manufacturing – stamping and machining ;Bevel Gear/Indexing Ratchet The part is supplied as a net shape with no secondary operations. It is fabricated to a typical density of 6.6g/cm3, and has a yield strength of 207MPa (30,000psi), and a 63 HRB typical hardness. P/M replaced a two-piece machined and welded assembly, offering a 70% cost savings ;Needle Driver and Distal Clevis The parts are made to a density range of 7.68-7.72g/cm3. The distal clevis has a 35-38 HRC hardness and an elongation of 10%. Tensile yield strength is 1100MPa (160,000psi). The needle driver has a 38-42 HRC hardness range and an elongation of 8%. The tensile yield strength is 1070MPa (155,000psi). Metal injection molding offered a cost savings of 90% compared to CNC machining the parts from bar stock ;Synchronizer Ring with Friction Lining The part is warm compacted to a density of more than 7.3g/cm3 in the teeth and more than 7.1g/cm3 in the ring body ;;粉末冶金技术的主要应用;典型的汽车用粉末冶金零部件 Main Bearing Cap Set VALVE SEAT AND VALVE GUIDE ;CONNECTING RODS Connecting Rod (fracture split) Ford Motor Company has already used more than 25 million Powder Forged (PF) connecting rods ；Total cost savings of over 20% are reported ;OIL PUMP GEARS SYNCHRONISATION SYSTEM ;2000、2005及2010年国内粉末冶金零件的总需求量,单位/吨 ;国外市场 世界粉末冶金零件总产量约为60万吨，我国约占4%，世界上超过1万吨/年的粉末冶金厂家约为12个。 国内与国外差距 产品水平低 在产品精度方面，少数企业尺寸精度可达IS07—8级，形位公差可达8—9级，与国外水平相比低1—2级，但一般企业约相差2—3级。产品质量不够稳定，产品内在重量和外观质量均有较大的差距 工艺装备落后 多数企业仍采用性能较差的设备、能耗大、效率低、炉温均匀性差，质量不稳定；国内还没有形成一个专业生产粉末冶金模具、模架的企业 ;企业技术经济效益与国外同类企业相比差距较大 ;;;;原料：元素粉末、合金粉末;;一、基本概念;（二）粉末颗粒的聚集状态;粉末性能简介（Powder Properties）;School of Materials Science and Engineering;School of Materials Science and Engineering;Scho