摘要
采用费氏粒度为2.97μmWC为原料制备出WC-23%(Fe-Co-Ni)合金,通过扫描电镜和X射线能谱仪等分析手段研究了碳含量和球磨时间对合金性能的影响。结果表明:碳的质量分数在4.9%~5.3%时,合金中的铁在烧结温度下可以与足够的碳(C)发生反应,形成Fe-C有限固溶体(γ-Fe),抑制了合金中脆性相(Fe_(3)W_(3)C)的生成,合金具有较高的强度(TRS>3100 N/mm^(2))和硬度(HRA>86);碳含量低于4.8%或高于5.4%时,则容易在合金中形成脆性相(Fe_(3)W_(3)C)或渗碳相致使合金的性能下降。球磨时间的长短将直接影响合金中铁与碳反应的程度,若球磨时间不足,粗大的铁相不能均匀地弥散在合金中,导致合金中的铁相富聚,且合金中的碳不能与铁充分发生反应,容易造成在碳含量低于4.7%合金仍存在渗碳假象,合金的抗弯强度和硬度下降。
WC-23 wt.%(Fe-Co-Ni)alloy is prepared from WC with a fischer size of 2.97 microns.The effects of carbon content and milling time on the properties of the cemented carbide are investigated by means of SEM and EDS.The results show that when the carbon content is 4.9 wt.%~5.3 wt.%,the iron in the cemented carbide can react with enough carbon(C)at sintering temperature to form Fe-C finite solid melt(γ-Fe),which inhibits the formation of brittle phase(Fe_(3)W_(3)C)in the cemented carbide,and the cemented carbide has high strength(TRS>3100 N/mm^(2))and hardness(HRA>86).When the carbon content is less than 4.8 wt.%or more than 5.4 wt.%,the brittle phase(Fe_(3)W_(3)C)or carburized phase is easily formed in the cemented carbide and the properties of the cemented carbide decrease.If the ball milling time is not enough,the coarse iron phase cannot be dispersed evenly in the cemented carbide,which leads to the enrichment of iron phase in the cemented carbide,and the carbon in the cemented carbide cannot fully react with the iron,so it is easy to make the carbon content lower than 4.7 wt.%,and the cemented carbide’s bending strength and hardness decrease.
作者
汪中玮
刘海军
Wang Zhongwei;Liu Haiju(Zhuzhou Xinke Cemented Carbide Co.Ltd.,Zhuzhou Hunan 412000,China)
出处
《硬质合金》
CAS
2021年第5期332-337,共6页
Cemented Carbides
关键词
碳含量
球磨时间
铁
硬质合金
carbon content
milling time
iron
cemented carbide
作者简介
汪中玮(1974-),男,硕士,总经理,工程师,研究方向为超细及纳米硬质合金制备技术。E-mail:361983575@qq.com。
