The main goal of the brazing process is to achieve a time, temperature, and atmosphere relationship that produces a high first pass yield rate for assemblies that have a clean appearance and excellent dimensional stability. Nothing hinders this goal as much as the oxidation of the parts that are brazed.
Effects of Oxidation on Brazing
Oxidation has several negative effects on the brazing process, some of which regard the quality of assemblies, and some which pertain to the value of the brazing process for the customer. Unless proper measures are taken to prevent metal from oxidizing while brazing services are performed, at least four negative results can be expected: assemblies will have a tarnished surface and weak braze joints, orders will take longer to complete, and services will cost more.
Oxidation causes metal to appear tarnished. On some metal, such as carbon steel, the presence of surface oxidation may not be an issue. However, for a chromium alloy like stainless steel, the presence of surface oxidation requires the brazing process be repeated, or the assembly to be pickled in an acid solution to remove the oxidation.
Weak Braze Joints
The pieces of an assembly are bound by filler metal that liquifies and wicks into the pores of the base metal via capillary action. Oxidation prevents the filler metal from adequately distributing between the work pieces by forming a layer between the base metal and filler metal. The resulting assembly will have weak dimensional stability that could lead to failure during service.
Increased Turnaround Time
A brazing process that fails to prevent oxidation results in a low first pass yield rate, which essentially increases the turnaround time for orders. The lower a brazing provider’s first pass yield rate, the less revenue it earns, and the less customers can depend on the company to produce a brazing order on short notice.
Over time, repeating the brazing process to achieve better results raises the overhead of the brazing services provider. This results in higher service costs for the customer, which in turn results in the provider losing customers to companies that offer better prices. Creating a brazing process that eliminates oxidation benefits both the customer and the service provider.
Need Brazing Services?
If so, Franklin Brazing is the company to call. Our PuroBrite™ system for brazing creates strong assemblies that are free of oxidation, and results in a first pass yield rate of nearly 100%. We have over 40 years of experience in brazing assemblies for automotive applications, aeronautical applications, and other industrial applications. For more information about our services, call us today at (800) 450-7782, or click here to use our contact form.