The second precaution necessary when brazing aluminum to stainless is...

We want to use our vacuum furnace to braze a 6061 aluminum part to a 400-series stainless steel but are concerned about whether that can be done in our furnace, which only is used for aluminum brazing.

Please note, first of all, that the aluminum-oxide layer on the surface of the aluminum is very thin – only about 40-angstroms thick! That’s VERY thin, since an angstrom is only about one ten-billionth of a meter thick.

Aluminum brazing is a growing industry around the world today, and I teach a lot about this topic in each of my brazing training seminars.

My recommendation is that you institute some QC tests on the plated parts that you receive back from your plater in order to evaluate the quality of that plating. The so-called “blister test” was the most important and valuable one we developed, and it should NEVER be done by the plating company but by YOU.

We plated the mating surfaces of our Inconel 738 components that were going to be nickel brazed, and the parts failed in service prematurely. An analysis showed that our brazing was OK, but the plating had peeled from the base metal causing the premature failure. How can we prevent this in the future?

People occasionally ask me for information about how to determine the strength of their brazed assemblies, which involve different types of base metals and different kinds of brazing filler metals (BFMs).

We braze thousands of special cooling baffles for our customer each year, mainly thin sheet-metal AMS 5536 (Hast-X) parent material and BNi-2 braze powder with overall good results.

Brazing expert Dan Kay answers a reader's question about fixturing.

We pick up where we left off last time with the procedure for making brazing paste.