放电等离子烧结制备的细晶铁基材料及其力学性能  

Mechanical properties of ultrafine grained iron-based alloy produced by spark plasma sintering

作　　者：李小强[1] 唐愈[1] 叶永权[1] 李元元[1] 

机构地区：[1]华南理工大学机械与汽车工程学院,广州510641

出　　处：《粉末冶金材料科学与工程》2011年第3期397-402,共6页Materials Science and Engineering of Powder Metallurgy

基　　金：国家高技术研究发展计划(863计划)资助项目(2007AA03Z112);广东省自然科学基金资助项目(x2jqB6080210);新世纪优秀人才支持计划资助项目(NCET-10-0364);中央高校基本科研业务费专项资金重点项目(2009ZZ0019)

摘　　要：采用高能球磨和放电等离子烧结,制备细晶Fe-2Cu-2Ni-1Mo-1C块体材料,在不同温度下对烧结试样进行回火处理,研究烧结温度和回火温度对该合金组织、硬度和横向断裂强度的影响。结果表明:烧结温度对合金密度和硬度影响不大,经650～800℃烧结可得到近乎全致密的铁基合金,相对密度达98%～99%,组织为马氏体、贝氏体、珠光体和残余奥氏体的混合组织,硬度为59～61 HRC。在650℃下烧结时横向断裂强度为2 260 MPa;烧结试样在400～600℃回火4 h,随着回火温度升高,初始烧结组织逐渐向球状珠光体转变,使得合金的硬度逐渐降低,横向断裂强度逐渐升高。经650℃放电等离子烧结和500℃回火热处理后的铁基合金的横向断裂强度最高达3 325 MPa,硬度大于51 HRC。Fe-2Cu-1Ni-1Mo-1C alloys with high relative density,excellent hardness and ultrafine grain were prepared by high-energy ball milling and subsequent spark plasma sintering（SPS） technique.The tempering treatment was further conducted,the effects of sintering temperature and tempering temperature on microstructure,hardness and transverse rupture strength were studied.Sintering temperatures show little influence on the density and hardness of the specimens and near fully dense specimens are obtained when SPS temperature ranges from 650 ℃ to 800 ℃.The microstructure of the as sintered specimens is composed of martensite,bainite,pearlite and austenite.The Rockwell hardness is in the range of 59~61 HRC and the highest transverse rupture strength reaches 2 260 MPa.After tempering treatment at 400~600 ℃ for 4 hours,the transverse rupture strength increases and the hardness decreases with the increase of the tempering temperature,resulting from the transformation of the sintered microstructure to globular pearlite.The specimens prepared by SPS at 650 ℃ and subsequent tempering at 500 ℃ perform an optimal combination mechanical property with transverse rupture strength of 3 325 MPa,and Rockwell hardness of 51HRC.

关 键 词：铁基合金 放电等离子烧结 力学性能 回火 

分 类 号：TF124[冶金工程—粉末冶金]