烧结工艺对铜铁基含油轴承组织与性能的影响  

Effect of Sintering Process on Microstructure and Properties of Copper-Iron-based Oil-impregnated Bearing

作　　者：李东宇 李小强[1] 李京懋 屈盛官[1] 徐各清 LI Dongyu;LI Xiaoqiang;LI Jingmao;QU Shengguan;XU Geqing(National Engineering Research Center of Near-Net-Shape Forming for Metallic Materials,South China University of Technology,Guangzhou 510640,China;Guangzhou Golden South Magnetic Material Co,Ltd,Guangzhou 511300,China)

机构地区：[1]华南理工大学国家金属材料近净成形工程技术研究中心,广州510640 [2]广州金南磁性材料有限公司,广州511300

出　　处：《材料导报》2021年第8期157-163,共7页Materials Reports

基　　金：国家自然科学基金基金(51474108);广州市科技计划项目(201807010075);广东省自然科学基金(2018B030311051)。

摘　　要：通过粉末冶金制备铜铁基含油轴承,并利用DSC、SEM和压缩试验等测试方法,研究了烧结气氛(100%N_(2)、75%H_(2)+25%N_(2)和100%H_(2)(体积分数))和烧结温度(825~885℃)对轴承材料的微观组织、含油率和力学性能的影响。结果表明:在烧结温度为865℃的条件下,100%N_(2)气氛下烧结时,铁粉表面的铁氮化合物和黄铜粉表面的氧化膜阻碍了两者间的冶金结合;100%H_(2)气氛下烧结时,Cu_(3)Zn相发生严重的脱锌现象。这两种气氛下烧结试样组织中存在较多形状不规则的缝隙和孔隙,显著降低了材料的含油率、硬度和压溃强度。75%H_(2)+25%N_(2)气氛下烧结时,粉末颗粒间的冶金结合较为充分,且Cu_(3)Zn相的脱锌程度较低,孔隙趋于球形,材料的含油率、硬度和压溃强度明显提升。在75%H_(2)+25%N_(2)气氛下,825℃和845℃烧结时,粉末颗粒之间未发生明显的冶金结合,硬度和压溃强度较低;烧结温度升高至865℃时,冶金结合程度提升,孔隙数量减少,试样的硬度和压溃强度明显提高;烧结温度继续升高至885℃时,试样发生过烧结,收缩率较大,含油率急剧下降。75%H_(2)+25%N_(2)气氛下,烧结温度为865℃时,烧结试样具有良好的综合性能,含油率、硬度和压溃强度分别为18.8%(体积分数)、43.7HB和271.1 MPa。The copper-iron-based oil-impregnated bearings were prepared by powder metallurgy,and DSC,SEM,compression tests were used to study the effects of sintering atmosphere(nitrogen,decomposed ammonia and hydrogen)and sintering temperature(825—885℃)on the microstructure,oil content and mechanical properties of the bearing materials.The results indicate that when the samples are sintered at 865℃under nitrogen atmosphere,the iron-nitrogen compound on the surface of iron powder and the oxide film on the surface of brass powder hinder the metallurgical bonding between iron powder and brass powder.When the samples are sintered under hydrogen atmosphere,severe dezincification of Cu_(3)Zn phase occurs.There are many irregularly shaped cracks and pores in the microstructure corresponding to these two atmospheres,which significantly reduces the oil content,hardness and crushing strength.When sintered under decompose ammonia atmosphere,the metallurgical bonding between the powder particles of the samples is sufficient,and the degree of dezincification of the Cu_(3)Zn phase is low.The pores tend to be spherical,and the oil content,hardness and crushing strength are significantly improved.When the samples are sintered at 825℃and 845℃under decompose ammonia atmosphere,no obvious metallurgical bonding occurs between the powder particles and the hardness and crushing strength are low.When the sintering temperature is increased to 865℃,the degree of metallurgical integration has increased,the number of pores is greatly reduced,and the hardeness and crushing strength are significantly improved.The sintering temperature is increased to 885℃,the sample is oversintering,the shrinkage is large,and the oil content decreases sharply.When sintered at 865℃under decompose ammonia atmosphere,the sintered samples have good comprehensive properties.The oil content,hardness and crushing strength are 18.8%(volume fraction),43.7 HB,and 271.1 MPa,respectively.

关 键 词：粉末冶金 铜铁基含油轴承 烧结工艺 压溃强度 脱锌 

分 类 号：TB333[一般工业技术—材料科学与工程]