The furnace atmosphere can be divided into two major parts; Gaseous and Vacuum. The gaseous atmospheres include both active and neutral gases. The neutral gas is generally nitrogen and the active gas will consist of one or several of the carbon monoxide, hydrogen, and hydrocarbon. The gases can be categorized as Reducing, Oxidizing, Carburizing, and Decarburizing atmospheres.
Each active gas can effect the brazing materials. The reducing effect can be balanced by the oxidizing effect. Similarly, the carburizing effect can be balanced by the decarburizing effect. It's important to keep the balance between those active gases in order to achieve atmosphere control.
The brazing atmospheres can also influence the heat transfer and post-braze cooling. The type of gas, the pressure, and the gas flow rate will also influence the heat transfer rate.
Although oxidation should be avoided, an atmosphere with low oxygen and low moisture levels will allow the filler metal to melt and flow into very tightly jointed clearances. The oxygen or moisture present in the joining environment will negatively interfere with wetting. Therefore, the quality of the joint will degrade if the oxygen and moisture levels rise.
Like Torrey Hills on facebook and get updates on all new whitepapers, etc.
www.facebook.com/torreyhillstechnologies
No comments:
Post a Comment