The Brazing Tungsten Carbide
When constructing industrial machine wear parts and tool, tungsten carbide is one of the main components or materials. That is because of the incredible properties such as high resistance to wear, abrasion heat, impact, and high cutting performance. However, joining carbide to the steel or other material (although steel is the most recommended) is critical for the performance of the tool. Brazing tungsten carbide is the most recommended technique for joining the two components to due to numerous benefits over the available alternatives such as soldering.
Brazing involves about placing a metallic braze alloy with fluxing agent between the tungsten carbide shank and the steel. Then, the assembly is heated until the braze alloy melts and flows to fill the gap between the tungsten carbide and steel. However, there are various variables that determine the quality and strength of the bond between the two components. First, check the condition of the two components i.e., carbide and steel. The carbide and the steel components should be cleaned off dirt and other particles thoroughly. That will enable braze alloy to wet their surfaces properly to form a strong chemical bond.
The tungsten carbide should be grit blasted or sanded while steel should be vapor greased or cleaned with caustic solution. With that you are able to remove residual oil, grease, dirt or other contaminants that can affect the wetting of the components. However, it is important to consider the choice of brazing alloy. There are numerous options in the market from pure copper to silver alloys. The most popular braze alloys consist of approximately 50% silver and include alloys with cadmium (BAg-6), without cadmium (BAg-24), with manganese (BAg-22), and with tin (BAg-7). These alloys come with exceptional properties such as the moderate melting point that ranges from 1150 to 1300ºF. They are also available in rods, wires, ribbons or tri-metal forms thus making them flexible in application.
It’s essential to note that the level of temperature during tool application can determine the choice braze material. For a high-temperature application, copper is the most recommended material. Compared to silver, copper has a lower tensile strength at room temperature. Copper can also retain its strength even when the temperatures 1000ºF. However, the choice of flux to minimize the level of oxidation should be correct depending on the prevailing conditions. You can use chromium, borax, boron, and silicon fluxes and so on depending on brazing temperatures. For higher blazing temperatures,” black” flux is better than “white” flux since it has higher boron content.
The Basic Brazing Steps
For the brazing tungsten carbide to be effective, there are basic steps to follow to make a strong joint. Failure to observe these steps could result in an inferior joint. Check out these steps:
- Start with applying influx to the steel surface
- Have the precut braze alloy steel and coat it with some influx
- Position the tungsten carbide shank/component
- Start heating the braze alloy
- Move the tungsten carbide component slightly to alloy the fumes or flux to escape.
- Allow the joint to cool slowly
- Use hot water to wash off excess flux
Using the right heating method for the assembly is critical for a strong joint. Most factories usually use batch furnaces, hand torches or high-frequency induction coils for brazing tungsten carbide. However, hand torches are fading away in brazing tungsten carbide due to high levels of oxidation. Overheating and under-heating of brazes can compromise the quality and strength of the joint. Avoid it.
At Wear Parts China, offers a range of brazing tungsten carbide services and products. We are equipped with the latest state of art equipment and highly trained and experienced welding experts. Therefore, our grinder wear pars, shredder parts, and wood chipper wear parts come with high braze joints. They can withstand the demanding conditions. In addition, wear parts China also provides external processing services for Brazing Tungsten Carbide.