Many of the problems of beryllium copper in resistance spot welding can be solved with resistance projection welding (RPW). Due to its small heat affected zone, multiple operations can be performed. Different metals of different thicknesses are easy to weld. in resistive
Projection welding uses wider cross-section electrodes and various electrode shapes that reduce deformation and sticking. Electrode conductivity is less of a problem than in resistance spot welding. Commonly used are 2, 3, and 4 pole electrodes; the harder the electrode, the longer the life.
Softer copper alloys do not undergo resistance projection welding, beryllium copper is strong enough to prevent premature bump cracking and provide a very complete weld. Beryllium copper can also be projection welded at thicknesses below 0.25mm. As with resistance spot welding, AC equipment is usually used.
When soldering dissimilar metals, the bumps are located in higher conductive alloys. Beryllium copper is malleable enough to punch or extrude almost any convex shape. Including very sharp shapes. The beryllium copper workpiece should be formed before heat treatment to avoid cracking.
Like resistance spot welding, beryllium copper resistance projection welding processes routinely require higher amperage. The power must be momentarily energized and high enough to cause the protrusion to melt before it cracks. Welding pressure and time are adjusted to control bump breakage. Welding pressure and time also depend on bump geometry. The burst pressure will reduce weld defects before and after welding.
Safe Handling of Copper Beryllium Like many industrial materials, copper beryllium is only a health hazard when handled improperly. beryllium copper in its usual
Solid shapes, finished parts, and completely safe in most manufacturing operations. However, in a small percentage of individuals, inhalation of fine particles may lead to poorer lung conditions. Using simple engineering controls, such as venting operations that generate fine dust, can minimize the hazard.
Because the welding melt is very small and not open, there is no special danger when the beryllium copper resistance welding process is controlled. If a mechanical cleaning process is required after soldering, it must be done by exposing the work to a fine particle environment.