粗颗粒碳化钨粉制备研究

Study on the Preparation of Coarse-grained Tungsten Carbide Powder

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摘要粗晶硬质合金因结晶性能好、结构缺陷少、亚晶尺寸粗大、显微硬度高、微观应变小等优点,广泛用于地矿工具和工程刀具等领域。根据行业常规标准,粗晶硬质合金的晶粒度应大于5μm,其中粗颗粒碳化钨粉体作为核心原料,其粒度控制对合金性能具有决定性影响。本研究旨在系统探究钨粉初始粒度、碳化温度及钴添加剂对碳化钨粉体粒度演变、晶体形貌及生长机理的影响规律。试验结果表明:在碳化温度≥1800℃时,碳化钨晶粒尺寸与原料钨粉粒度呈显著正相关;而当碳化温度<1800℃时,二者呈现负相关趋势。碳化钨晶粒生长动力学呈现温度依赖性双阶段特征,晶粒生长速率随温度升高呈现先快后慢趋势:在低温区间(≤1800℃),晶粒通过表面扩散主导的固相烧结机制快速生长,形成不规则多面体形貌;在高温区间(>1800℃),晶粒生长速率变慢,此时热激活能充分降低原子迁移势垒,促使晶粒通过表面重构形成完整六方晶系结构。钴添加剂的引入可显著促进碳化钨晶粒生长,其机制可归因于钴液相中W-C-Co三元共晶体系形成的溶解-析出过程,相较于传统固相聚集机制具有更优的动力学优势。本研究为粗晶硬质合金原料的可控制备提供了理论依据与工艺优化路径。 Coarse-grained cemented carbides,characterized by excellent crystallinity,fewer structural defects,coarse subgrain size,high microhardness,and low microstrain,are widely used in geological mining tools and engineering cutters.The standard for coarse-grained cemented carbides specifies a grain size greater than 5μm,where coarse-grained tungsten carbide(WC)powder serves as the critical raw material.Therefore,investigating key factors influencing WC powder granularity is of significant importance.This study systematically examines the effects of tungsten(W)powder particle size,carburization temperature,and cobalt(Co)additives on the granularity,morphology,and properties of WC.Results indicate that the particle size of raw W powder positively correlates with that of WC,with coarser W powder yielding coarser WC.Elevated carburization temperatures promote WC grain growth,and the addition of Co further enhances this process.Mechanistic analysis reveals that the dissolution-precipitation growth mechanism of WC crystals in the liquid phase outperforms the solid-phase particle aggregation and crystallization mechanism.

作者邹爱忠梁勇杨亮万林生 ZOU Aizhong;LIANG Yong;YANG Liang;WAN Linsheng(School of Metallurgical Engineering,Jiangxi University of Science and Technology,Ganzhou 341000,Jiangxi,China;Hejun Vocational College,Ganzhou 341000,Jiangxi,China)

机构地区江西理工大学冶金工程学院和君职业学院

出处《中国钨业》 2025年第1期44-49,共6页 China Tungsten Industry

基金国家自然科学基金(52464046) 江西省自然科学基金重点项目(20242BAB26062)。

关键词粗颗粒碳化钨粗晶粒合金溶解与析出颗粒聚集结晶 coarse-grained tungsten carbide coarse-grained alloy dissolution and precipitation particle aggregation crystallization

分类号 TF123.31 [冶金工程—粉末冶金]

作者简介邹爱忠(1978-),男,江西新余人,高级工程师,主要从事钨冶炼及地矿合金、超粗合金研发与生产;通讯作者:万林生(1950-),男,江西南昌人,教授,主要从事钨湿法冶金研究。