A Comparative Study On Different Joining Techniques For PM-HIP Evacuation Tubes

Abstract

The main purpose of evacuation tubes in powder metallurgically-based (PM) Hot Isostatic Pressing (HIP) lies in the evacuation and outgassing of the capsule. Conventional HIP capsules are made of sheet-metal which exhibits good weldability and therefore, it is easy to join the evacuation tube. With the emerging technologies of Additive Manufacturing (AM) it is now possible to design more complex capsules for HIP. Additionally, wear-resistant materials can be utilized. Yet, these materials are known to be difficult to weld. This study compares three different approaches to bond an AISI 304 evacuation tube to a HIP capsule made by Electron Beam Melting (EBM) from high carbon tool steel AISI A11. Capsules were bonded by TIG welding as well as brazing with conventional and a customized filler material based on thermodynamic calculations. Subsequent consolidation by HIP, microstructural analysis and argon-measurements revealed the feasibility and limits of all three approaches for gas-tight bonds.

Authors 5

1. Markus Mirz Aachen Institute for Materials Applications in Mechanical Engineering

   RWTH Aachen University

   Affiliation as printed

   Institute for Materials Applications in Mechanical Engineering, RWTH Aachen University

2. Marie Franke-Jurisch

   Fraunhofer Institute for Manufacturing Technology and Advanced Materials · Fraunhofer Institute for Manufacturing Technology and Advanced Materials Dresden

   Affiliation as printed

   Fraunhofer Institute for Manufacturing Technology and Advanced Materials IFAM

3. Simone Herzog Aachen Institute for Materials Applications in Mechanical Engineering

   RWTH Aachen University

   Affiliation as printed

   Institute for Materials Applications in Mechanical Engineering, RWTH Aachen University

4. Anke Kaletsch Aachen Institute for Materials Applications in Mechanical Engineering

   RWTH Aachen University

   Affiliation as printed

   Institute for Materials Applications in Mechanical Engineering, RWTH Aachen University

5. Christoph Broeckmann Aachen Institute for Materials Applications in Mechanical Engineering

   RWTH Aachen University

   Affiliation as printed

   Institute for Materials Applications in Mechanical Engineering, RWTH Aachen University