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以共晶铸铁(eutectic cast iron,ECI)作为C源,通过熔铸时渗碳体的原位生成及渗碳体石墨化工艺制备石墨黄铜.利用SEM和EDS分析石墨黄铜的显微组织,探讨了显微组织与力学性能和切削性能的关系.结果表明:铸造过程中原位生成的渗碳体通过石墨化退火后分解成石墨颗粒均匀弥散地分布于黄铜基体上,颗粒尺寸为3~6μm,铸铁添加量为7%时石墨颗粒出现偏聚.随着铸铁添加量的增加,基体组织不断细化,抗拉强度和显微硬度增加,伸长率降低;随着石墨体积分数的增大,石墨黄铜的切屑形貌得到不断改善.当铸铁添加量为5%时黄铜的切屑形貌最好,为短片状和C型,其切削性能与铅黄铜HPb59-1相当.
The eutectic cast iron (ECI) was used as C source to prepare graphite brass by in situ formation of cementite during cementing and cementite graphitization. The microstructure of graphite brass was analyzed by SEM and EDS, The relationship between microstructure and mechanical properties and machinability was discussed.The results show that the cementite generated in situ during the casting process is decomposed into graphite particles by graphitization annealing and dispersed uniformly on the brass matrix with particle size of 3 ~ 6μm, segregation of graphite particles occurs when the amount of cast iron is 7% .With the increase of the amount of cast iron, the matrix microstructure is refined, the tensile strength and microhardness increase, and the elongation decreases. With the increase of graphite volume fraction Large, graphite brass chip morphology has been continuously improved.When the cast iron is added in an amount of 5%, the best brass chip morphology, short and C type, the cutting performance and lead brass HPb59-1 quite.