金刚石工具预合金代钴粉末的研究及应用

Research and application of cobalt-substitute prealloy powder for diamond tools

近年,国内外开展了金刚石工具代钴粉末的研究。本文采用水雾化法开发了三种预合金代钴粉末:对粉末的基本属性、形貌,粉末的相组成,粉末的差热性进行了分析研究;测定了它们的烧结密度、硬度、抗弯强度、弹性模量随热压烧结温度变化的规律;采用作者自行建立的磨料磨损试验方法,测定了它们的质量磨损百分率(即耐磨性);测定了它们的冷压生坯密度、模拟生坯强度以及高频钎焊的结合力矩;观察了热压烧结SEM腐蚀组织和SEM断口形貌。结果表明: 三种预合金粉末有着优良的低温烧结性能和耐磨性,表现出接近于超细钴和相当于国外代钴粉末的优良的物理、机械性能,对金刚石把持力高;具有高的高频钎焊结合力矩;粉末成本较低,用粉量可降低。实际切割花岗石、混凝土,切割锋利,使用寿命长。

In recent years, cobalt-substitute prealloy powder for diamond tools were researched intensively. In this article, three kinds of prealloy powder were developed by water atomization method. The base attribute, pattern, phase composition, differential thermal analysis of powder were researched. Sintered density, hardness, bend strength, Young＇s modulus were researched as hot pressed sintering temperature changing. By using abrasive wearing equipment upbuih by the authors, the wear resistance were determined. Green-pressing density, simulated green-pressing strength and bonding momental of high frequency brazing were assayed. SEM corrosion structure and SEM appearance of fracture were observed. The results showed that the three kinds of prealloy powder have excellent low temperature sintering characteristics and good wear resistance. They have excellent physical and mechanical characteristics close to uhrafine cobalt and imported preaUoy powder, good retention to diamond and excellent bonding momental for high frequency brazing. At one time, they have lower cost and reduced dosage. When used in making diamond saw segment for cutting granite and concrete, they feature free cutting and long lifespan.