Vacuum Brazing for Conformal Cooled Molds

  • Date: May 16, 2017
  • Time: 11:15 AM
  • Room: Calhoun Salon

In order to accomplish an optimized heat flow to the hot molded plastic parts, it becomes necessary for the cooling channels to follow the geometry of the part. Due to this fact, a more complex channel design becomes unavoidable, which cannot be realized by gun-drilling and plugging.

Vacuum brazing is a very successful method to manufacture conformal cooled molds. Vacuum brazing is being used for a large variety of parts, starting with mass produced simple parts to very complex, unique parts. What makes this manufacturing method interesting is the wide range of materials and material combinations, which can be joined. For conformal cooling the usual procedure is, to partition the mold into a distinct number of layers, incrementally machine the channels for each layer, and bond the layers of the assembly via vacuum brazing. Even though this procedure offers a huge potential, the brazing is the critical step that requires special knowledge.

This presentation will discuss the most important issues of this special bonding. The presentation will start with a brief review of the fundamentals and the state of the art of the furnace design and operation. The process performance depends largely on the filler metal and the joint design, both topics will be discussed in detail. The most important requirements for a successful brazing, like the surface condition, roughness and tolerances, process parameters, as well as commercial aspects will be shown.