Min Fanlu, Wang Shiyu, Yu Songbai, Yang Hao, Yao Zhanhu, Ni Jianzhong, Zhang Jianfeng
Key Laboratory of Geomechanics and Embankment Engineering, Hohai University, Ministry of Education, Nanjing 210024, China.
College of Civil and Transportation Engineering, Hohai University, Nanjing 210024, China.
Materials (Basel). 2023 Aug 8;16(16):5506. doi: 10.3390/ma16165506.
The exploration of coarse-grained WC cemented carbide has become a research hotspot for its application in the fields of rock cutting and mining; a key issue is how to achieve uniform dispersion and densification of the sintered phase, as well as how to obtain better mechanical properties. In this paper, chemical co-precipitation, combined with hydrogen reduction, was adopted. CoCl·6HO and CeCl were used as precursors to coat Co nanoparticles on the surface of WC powder while introducing different contents of cerium; the samples were then sintered and densified to obtain WC-Co(Ce) hard alloy materials. On the surface of the obtained WC particles, the distribution of Co(Ce) nanoparticles was uniform and dense, and the average particle size after sintering was 4.2 μm, which lies in the coarse-grained range. The addition of cerium elements significantly improves the flexural strength and impact toughness; when the cerium content was 0.5% and 0.6%, they increased to 2487 MPa and 36.1 kJ/m, respectively. The addition of Co(Ce) through the co-precipitation method could achieve a uniform coating of the Co phase, along with the uniform dispersion and densification of the sintered phase, giving the WC-Co(Ce) cemented carbide excellent properties.
粗晶WC硬质合金因其在岩石切割和采矿领域的应用而成为研究热点;关键问题是如何实现烧结相的均匀分散和致密化,以及如何获得更好的力学性能。本文采用化学共沉淀结合氢气还原的方法。以CoCl·6H₂O和CeCl₃为前驱体,在WC粉末表面包覆Co纳米颗粒,同时引入不同含量的铈;然后对样品进行烧结和致密化处理,得到WC-Co(Ce)硬质合金材料。在所获得的WC颗粒表面,Co(Ce)纳米颗粒分布均匀且致密,烧结后的平均粒径为4.2μm,属于粗晶范围。铈元素的添加显著提高了抗弯强度和冲击韧性;当铈含量为0.5%和0.6%时,抗弯强度和冲击韧性分别提高到2487MPa和36.1kJ/m²。通过共沉淀法添加Co(Ce)能够实现Co相的均匀包覆,以及烧结相的均匀分散和致密化,赋予WC-Co(Ce)硬质合金优异的性能。