It is widely used in oil and gas, chemical industry, engineering machinery, fluid control and other fields. Cemented carbide is a material pressed by powder metallurgy process. During the pressing process, we will often encounter several major problems, and briefly analyze the reasons.
Cemented carbide is an alloy material made of hard compounds of refractory metals and bonding metals through powder metallurgy. It has high hardness, wear resistance, strength and toughness. Because of its unique properties, it is often used to make rock drilling tools, mining tools, drilling tools, measuring tools and so on. It is widely used in oil and gas, chemical industry, engineering machinery, fluid control and other fields. Cemented carbide is a material pressed by powder metallurgy process. During the pressing process, we will often encounter several major problems, and briefly analyze the reasons.
1. In the process of cemented carbide pressing, the more common pressing waste is delamination
It appears along the edge of the briquetting block, forms a certain angle with the pressure surface, and forms a neat interface called delamination. Most delaminations start at the corners and extend into the compact. The cause of the delamination of the compact is the elastic internal stress or elastic tension in the compact. For example, the cobalt content of the mixture is relatively low, the carbide hardness is high, the powder or material is finer, the forming agent is too little or unevenly distributed, the mixture is too wet or too dry, the pressing pressure is too large, the unit weight is too large, the pressing The block shape is complicated, the mold finish is too poor, and the table is uneven, which may cause delamination.
Therefore, improving the strength of the briquette and reducing the internal stress and elastic after-whistling of the briquette are effective methods to solve delamination.
2. In the process of cemented carbide pressing, there will also be unpressed (obvious particles) phenomenon
Since the hole size of the green compact is too large, it cannot completely disappear during the sintering process, so that there are more special holes in the sintered body. The material particles are too hard, the material particles are too coarse, and the loose material is too large; the loose material is not evenly distributed in the mold cavity, and the unit weight is low. May cause failure to press well.
3. Another common phenomenon of suppressed waste products in cemented carbide is cracks
The phenomenon of irregular local fracture in the compact is called crack. Because the tensile stress inside the compact is greater than the tensile strength of the compact. The internal tensile stress of the compact comes from the elastic internal stress. The same factors that affect delamination also affect cracking. The following measures can be taken to reduce the occurrence of cracks: prolong the holding time or pressurize multiple times, reduce the pressure, single weight, improve the mold design and appropriately increase the mold thickness, speed up the demoulding speed, increase the molding agent, and increase the bulk density of the material, etc.
The whole production process of cemented carbide is very critical. Zhuzhou Xinterui Tools Co., Ltd. has been specialized in the production of cemented carbide for 18 years. If you have any questions about cemented carbide production, please pay attention to zzcenturytool.cn
