Problem: We are getting into 3D printing of components. Because of the size of the finished component, our 3D-printing equipment only allows us to 3D print smaller subsections of the finished product and then join them together to make the final assembly. We can share that the metals involved are nickel-based superalloys, and we were wondering if brazing could be used to join those smaller 3D-printed subsections together to create the final (much larger) assembly. Is brazing a reasonable choice for this?
Answer: Yes, brazing is an excellent choice to join 3D-printed parts together. It is already being done today in a number of brazing shops.
Discussion: When brazing 3D-printed parts together, the same fundamental criteria apply for 3D-printed parts as for any other metallic parts being brazed. These fundamental criteria are shown in Table 1.
People are concerned that the surface of a 3D-printed part may be such that it cannot be reasonably joined to another similar part. That is not true. As with any other metal part, the surface needs to be free of any oils, lubricants or oxides. Thus, it may be necessary to prep the surfaces to be joined by machining, grinding, cutting, etc., so that a smooth, flat, oxide-free surface is ready to be joined.
You indicated in your note that you were 3D printing a nickel-based superalloy. If this is the case, then you should be able to braze them as you would any other nickel-based component, and standard brazing processes/procedures would apply. Sometimes people think that because 3D printing is involved such parts have unique properties that cannot be joined by standard joining processes. That is not the case at all. 3D-printed parts are already being brazed together, and they are being handled as any other metal parts would be that need to be brazed.
We will conclude this discussion next time in part 2.