BrazeLet^® Ni613P-9002

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-9002 is typically in use for printing thin paste layers of about 0.05 – 0.2 mm on flat plates, on top of structured plates or fins by use of screens or stencils. A typical application is the printing on parts for flat heat exchangers. The use of rubber squeegees is recommended. Reliable printing requires a precise positioning fixture combined with the use of vacuum table or clamping device. Typical printing speed is 300 mm/s. Thin printing lines should have a width of >0.3 mm, small dots diameter should be >1 mm. The solvent based brazing paste BrazeLet Ni613P-9002 increases productivity wherever drying of the paste is an issue. The paste has no settlement, and no stirring is required 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. The drying time varies depending on thermal mass, design of the parts and the used furnace and needs to be established. After drying, the paste has excellent adhesion to the metal sheet.