If you’re joining two flat parts, you can simply rest one on top of the other. 127 mm) still produce joints of 100,000 psi (689.5 MPa) tensile strength. Look at the chart again, and see that clearances ranging from. 0015” (.038mm.) But in ordinary day-to-day brazing, you don’t have to be this precise to get a sufficiently strong joint.Ĭapillary action operates over a range of clearances, so you get a certain amount of leeway. So the ideal clearance for a brazed joint, in the example above, is in the neighborhood of. Also, capillary action is reduced, so the filler metal may fail to fill the joint completely again lowering joint strength. When the clearance is narrower than this, it’s harder for the filler metal to distribute itself adequately throughout the entire joint and joint strength is reduced.Ĭonversely, if the gap is wider than necessary, the strength of the joint will be reduced almost to that of the filler metal itself. Note that the strongest joint (135,000 psi/930.8 MPa) is achieved when the joint clearance is. It shows how the tensile strength of the brazed joint varies with the amount of clearance between the parts being joined. The following chart is based on brazing butt joints of stainless steel, using Easy-Flo® filler metal. This means, in almost all cases- a close clearance. Therefore, during the brazing process, you should take care to maintain a clearance between the base metals to allow capillary action to work most effectively. The same brazing process steps must be taken, although they may be performed in a different manner.įor more on the uses of brazing, watch this video.īrazing process Step 1: Good Fit And Proper Clearancesīrazing, as we’ve seen, uses the principle of capillary action to distribute the molten filler metal between the surfaces of the base metals. But everything said about manual brazing applies as well to mass production brazing. They are generally simple to perform (some may take only a few seconds), but none of them should be omitted from your brazing operation if you want to end up with sound, strong, neat-appearing joints.įor the sake of simplicity, we'll discuss these six brazing process steps mainly in terms of "manual brazing," that is, brazing with hand-held torch and hand-fed filler metal. How to braze? There are six fundamentals of brazing that every brazer should follow to ensure consistent and repeatable joint quality, strength, hermeticity, and reliability. These brazing procedures boil down the brazing process to six basic steps. But even a properly-designed joint can turn out imperfectly if the correct brazing process steps are not followed. We’ve said that a brazed joint “makes itself”-or that capillary action, more than operator skill, insures the distribution of the filler metal into the joint. The Importance of Proper Brazing Proceduresīrazing is ideally suited for joining of dissimilar metals and is performed at relatively low temperature.
0 Comments
Leave a Reply. |