Morphology of eta phase in cemented carbides with Fe-based binders influenced by carbon content and nitrogen atmosphere
Morphology of eta phase in cemented carbides with Fe-based binders influenced by carbon content and nitrogen atmosphere
复制标题
铁基粘结剂硬质合金中 eta 相的形貌受碳含量和氮气氛的影响
DOI：
10.1016/j.ceramint.2019.07.063
复制
发表时间：
2019
影响因子：
5.2
通讯作者：
Lengauer Walter
中科院分区：
文献类型：
--
作者：
Zhou Peng;Du Yong;Lengauer Walter
采用热力学计算设计了缺碳WC-Fe-Ni硬质合金，并在400毫巴氩气或氮气中于1440°C下进行液相烧结而制备。微观结构表征表明，η相在冷却阶段分解并产生粘结剂池。随着碳含量的增加，η相和粘结剂池在消失之前从分散的颗粒演变为大尺寸的簇。 η相的高温稳定性是这种形貌演化的关键因素。氮气氛略微降低了硬质合金中η相的稳定性。由于低碳缺陷，在氮气中烧结后显微组织中的η相完全分解。目前的硬质合金的维氏硬度几乎恒定，而韧性则受到 η 相和 η 引起的偏析的影响。
Carbon-deficient WC-Fe-Ni cemented carbides were designed using thermodynamic calculations and prepared by liquid-phase sintering at 1440 °C in 400 mbar argon or nitrogen. Microstructural characterization showed that the η phase decomposed and produced binder pools in the cooling stage. With increased carbon content, the η phase and binder pools evolved from dispersed particles to large-sized clusters before disappearing. The high-temperature stability of the η phase is the key factor for this morphology evolution. The nitrogen atmosphere slightly decreased the stability of the η phase in cemented carbides. With a low carbon deficiency, the η phase in the microstructure completely decomposed after sintering in nitrogen. The Vickers hardness was nearly constant in the present cemented carbides, while the toughness was influenced by both the η phase and the η-caused segregation.