BrazeLet^® Ni613P-9012

The nickel-based brazing alloy BrazeLet Ni613, features a best in class wetting behaviour on stainless steel material in vacuum or protective atmosphere (dry hydrogen or argon). Its high level of alloyed chromium results in a superior hot gas and acid corrosion resistance. The brazing alloy is best suited for brazing heat exchangers such as exhaust gas recirculation (EGR) coolers in automotive or drinking water applications. Compared to most of the standard nickel-based brazing alloys, BrazeLet Ni613 is able to fill larger gaps without brittle phase lines or cracks. The resulting micro hardness in the brazed joint microstructure is less than half when compared to BrazeLet BNi5. This leads to a more reliable and safe brazing as well as more flexibility in part tolerances.

The brazing paste BrazeLet Ni613P-9012 is typically in use for printing thick paste layers of about 0.2 to 0.6 mm on flat parts or on top of structured parts by use of screens or stencils. A typical application is printing of paste on hole plates of tube bundled heat exchangers. The use of rubber squeegees is recommended. Reliable printing requires precise positioning fixture tool by use of vacuum table or clamping device. Typical printing speed is 100 mm/s. Thin printing lines should at least have a width twice the printing thickness and the small dots diameter should be three times the printing thickness or greater. Printing accuracy is very precise as the paste maintains its shape during drying.
 
The solvent based BrazeLet Ni613P-9012 increases productivity wherever drying of the paste is an issue. It has no settlement, and no stirring is needed in the equipment. However, when opening a can from stock it is always recommended to stir the paste. The printed parts can be dried with standard drying process (hot air) at 120 – 170 °C. Here, the drying time needs to be established as it varies depending on thermal mass, parts design and the used furnace. After drying, the paste has excellent adhesion to the metal sheet.