Introduction of bending strength of cemented carbide

We all know that cemented carbide has the characteristics of high hardness and good wear resistance. It is an indispensable tool material for machinery, metallurgy, mining, oil drilling, aerospace, fluid control and other industries. Because of the brittleness of cemented carbide, it is very important to study the bending strength of cemented carbide in the development and application.

The results show that the bending strength of cemented carbide and the type of bonding phase in the material are discussed. The content is related to the particle size, the carbon content of the alloy, sintering process, heat treatment process, microstructure defect and residual stress.

Any material will contain a certain number of defects, such as holes, impurities and microcracks. These defects can lead to a reduction in the strength of the material. For plastic materials such as copper and low carbon steel, the number of defects and average size are the main factors affecting the strength, while for brittle materials such as hardened steel and cemented carbide, the number of defects larger than the critical size determines the strength. That is, the strength value depends on the probability of large-size defects, and the probability of large-size defects increases with the increase of volume, that is, the larger the volume is, the lower the strength is.

The bending strength of cemented carbide decreases with the increase of temperature. The creep of cemented carbide will occur when it is loaded for a long time at high temperature. The average bending strength of cemented carbide increases with the decrease of WC particle size, but the dispersion of flexural strength increases.

The average bending strength of cemented carbide increases with the uniformity of WC particle size, and the dispersion of flexural strength decreases.

So, the higher the bending strength of cemented carbide, the better the impact resistance? The impact resistance is the performance index used under the impact load, and the bending strength is the performance index used under the static load. Generally, when the material has high hardness and high wear resistance; When the bending strength is high, the impact toughness is also high. But the higher the hardness of the material, the lower the bending strength and impact toughness. The bending strength of cemented carbide is lower than that of high speed steel, and even YG8 cemented carbide with high bending strength has only about half of the high-speed steel. The higher the cobalt content in cemented carbide, the higher the strength and the same cobalt content, the bending strength of WC tic Co alloy decreases with the increase of TiC content. Besides carbide, the size of WC grain also affects the strength of cemented carbide, and the bending strength of coarse carbide is higher than that of medium grain cemented carbide. Cemented carbide is a kind of material with high bending strength and impact toughness, and it is widely used in modern industry.