摘要
采用熔炼铸造和粉末冶金法制备铋含量为20%(质量分数)的低铋含量铋锰铁合金,用扫描电镜/能谱仪分析合金的显微组织。结果表明,采用熔炼铸造法制备的Bi-Mn-Fe合金存在严重的区域偏析,试样中心组织为铋相+BiMn化合物+Mn(Fe)相,表层为Mn(Fe)相+细小的纯铋相。采用粉末冶金法制备的Bi-Mn-Fe合金组织由Mn(Fe)相和均匀分布的铋相组成,组织中未发现BiMn化合物。在铋的熔点附近温度下对Bi-Mn-Fe合金进行烧结时,适合的烧结时间为15 30 min。采用熔铸法很难制备出合乎质量要求的低铋含量Bi-Mn-Fe合金,而粉末冶金方法是制备低铋含量Bi-Mn-Fe合金的有效方法。
By means of SEM/EDX analysis, the microstructures of Bi-Mn-Fe alloy with mass fraction of 20% Bi prepared by fusion casting and powder metallurgy methods were investigated. The results show that there exists severe zone segregation in Bi-Mn-Fe alloy prepared by fusion casting method. The microstructure in the center of the Bi-Mn-Fe alloy specimen prepared by fusion casting is composed of Bi＋BiMn＋Mn （Fe） phase. The microstructure of the specimen surface consists of Mn （Fe） phase and small bismuth particles. The microstructure of the Bi-Mn-Fe alloy prepared by powder metallurgy composes ofBi＋Mn （Fe） phase, which distribute uniformly in alloy; and BiMn compound can not be found in the alloy. When Bi-Mn-Fe alloys are sintered at temperatures near the melting point of bismuth, the adequate sintering time is 15-30 min. It is difficult to prepare low bismuth content Bi-Mn-Fe alloy by fusion casting method which can conform to the quality requirements. Powder metallurgy method is an effective method for preparation of low content bismuth Bi-Mn-Fe alloy.
出处
《粉末冶金材料科学与工程》
EI
北大核心
2013年第5期741-747,共7页
Materials Science and Engineering of Powder Metallurgy
基金
常州市科技支撑(工业)计划项目(CE20110042)
江苏省青蓝工程资助
