Cemented carbide is known as "industrial teeth" because of its high strength and hardness as well as excellent wear resistance and corrosion resistance. It is widely used in aerospace, chemical industry, engineering machinery, metallurgy, oil drilling, mining tools, Ship equipment and other fields. In most commonly used fields, tungsten carbide part is often necessary to firmly be connected with other steel bodies,brazing is a commonly used process for this connection. However, desoldering is often prone to occur during cemented carbide brazing, which is a very Annoying question. What is the cause of the desoldering problem?Oston Carbide will help to find out the reasons.
Let’s check it one by one in terms of flux, solder, brazing process, etc.:
First of all, if the strength of the solder used in brazing is not strong enough, it does not meet the working standard or the wettability of the solder to the cemented carbide is poor, and the cemented carbide tool will be directly desoldered. Therefore, when choosing brazing material, it must be professionally and reasonably calculated and verified, and it must be deployed in a certain proportion.
Secondly, desoldering occurs due to improper selection of flux during cemented carbide brazing. In addition, if the melting temperature of the flux does not match the melting temperature of the solder, it cannot play a good deoxidation effect. Therefore, the choice of flux for cemented carbide tools is very important when brazing.
Besides, if the heating temperature during brazing is too high, the brazing material will be oxidized and porosity,the welding temperature is preferably controlled at 30~50℃ above the liquidus line of the solder. In addition, pay attention to preheating when brazing carbide, eliminate pores and slag inclusions to make the welding full!
Finally, the cemented carbide brazing surface has not been sandblasted or polished before brazing, and the oxide layer on the cemented carbide brazing surface will affect the wetting effect of the solder and affect the strength of the brazing seam. Therefore, when welding carbide tools, the welding surface should be cleaned first.
The performance of cemented carbide will also affect the quality of brazing. When the strength of cemented carbide is higher, the possibility of cracks during brazing is smaller. On the contrary, brazing cracks are more likely to occur. However, the hardness and strength of cemented carbide are inversely proportional to each other. Therefore, when we use cemented carbide, we must combine our actual needs and processing environment, and choose the appropriate cemented carbide grade to avoid desoldering.
Oston Carbide provides different brazing materials, high-frequency induction brazing, flame brazing, resistance brazing, vacuum brazing and other technologies are applied to welding applications of various products. According to the conditions and product requirements, we can provide customers with more comprehensive and high-quality precision parts and assemblies.
