网状基体和核心的特征对网状结构硬质合金抗弯强度的影响

Influence of Mesh Substrate and Core Feature on Rupture Strength of Cellular Cemented Carbide

网状结构硬质合金是近年来发展起来的一类新型硬质合金。本文制备了一种由球形或类球形团粒和网状基体复合而成的网状结构硬质合金样品,其团粒与网状基体的成分和性能差别较大,重点对影响网状结构硬质合金抗弯强度的因素进行了研究。结果表明:网状结构硬质合金的抗弯强度与网状基体的强度、孔隙度和表面状态关系密切,而团粒的强度和混合比例对抗弯强度影响较小。提高网状相强度、降低孔隙度和提高表面光滑度均可显著提高网状结构硬质合金的强度。与真空烧结相比,压力烧结明显降低样品的孔隙度,其抗弯强度大幅度增加。随着团粒分布均匀性的提高,样品表面光滑度提高,其抗弯强度也得以提高。

Reticular carbide is a new type of cemented carbide developed in recent years. Cellular cemented carbide samples composed of spherical or spherical pellets and mesh substrates were prepared in this article. The composition and performance of the aggregate and the mesh matrix were different. The influence factors on the transverse rupture strength（TRS） of the cellular cemented carbide were investigated. The results show that the TRS of the cellular cemented carbide is closely related to the matrix strength, porosity and surface flatness. At the same time, the agglomerate strength and mixing ratio have less influence on the TRS. With the increase of matrix strength, decrease of porosity and increase of surface flatness, the TRS of the cellular cemented carbide is obviously increased. Compared with vacuum sintering, pressure sintering significantly lowers porosity of the sample, and the flexural strength of the sample is increased significantly. With the improvement of the uniformity of the distribution of the pellet, surface smoothness of the sample increases, and the bending strength is improved.