Tungsten Carbide Button Failure Improvement (2/2)

Except controlling WC powder in grinding state, WC granularity distribution also has an importance effect on the uniformity of alloy grain size. If the WC powder particle size distribution is wide, which is quite different size, after grinding difference WC grain size will become bigger and bigger, its surface energy difference increases accordingly. In the process of sintering, dissolution and precipitation reaction becomes more remarkable and WC grain grows easily, which forms uneven alloy grain size. In other words, tungsten carbide button granularity depends on WC powder granularity distribution. Therefore, in the process of preparation, we should not only pay attention to the granularity of WC powder, the granularity distribution but also can not be ignored.

WC powder granularity and distribution in raw material is one of reasons that affecting tungsten carbide button granularity and distribution, ball milling process and its alloy ball also has an impact on the granularity finally. In the process of ball milling, the ratio of ball and material, ball milling time, the shape and quality of alloy ball are all the key influencing quality. Actually, alloy ball will be milled smaller and smaller, which indicates the part of milled get into the material. This means that it should be used in the alloy grain size and similar material prepared alloy ball can guarantee mixture size and uniformity.

Control alloy two-phase region refer to the same alloy grain size and the same Co content, the need to adjust the carbon content of the alloy, it is in between the two-phase region. Through confirm the total amount of carbon and the amount of free carbon to achieve more precise control of carbon, so that carburization and decarbonization phenomenon does not occur. It should be noticed that the choice of forming agent, degreasing sintering process of selection and to avoid direct contact with air to prevent oxidation, if necessary, purged with nitrogen during storage protection.

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