Preliminary Investigations of Joining Technologies for Attaching Refractory Metals to Ni-Based Superalloys

Physics

Scientific paper

Rate now

  [ 0.00 ] – not rated yet Voters 0   Comments 0

Details

Joining, Welding, Ceramics And Refractories, Metals, Semimetals, And Alloys, Structural And Shielding Materials, Spaceborne And Space Research Instruments, Apparatus, And Components

Scientific paper

In this study, a range of joining technologies has been investigated for creating attachments between refractory metal and Ni-based superalloys. Refractory materials of interest include Mo-47%Re, T-111, and Ta-10%W. The Ni-based superalloys include Hastelloy X and MarM 247. During joining with conventional processes, these materials have potential for a range of solidification and intermetallic formation-related defects. For this study, three non-conventional joining technologies were evaluated. These included inertia welding, electro-spark deposition (ESD) welding, and magnetic pulse welding (MPW). The developed inertia welding practice closely paralleled that typically used for the refractory metals alloys. Metallographic investigations showed that forging during inertia welding occurred predominantly on the refractory metal side. It was also noted that at least some degree of forging on the Ni-based superalloy side of the joint was necessary to achieve consistent bonding. Both refractory metals were readily weldable to the Hastelloy X material. When bonding to the MarM 247, results were inconsistent. This was related to the higher forging temperatures of the MarM 247, and subsequent reduced deformation on that material during welding. ESD trials using a Hastelloy X filler were successful for all material combinations. ESD places down very thin (5- to 10-μm) layers per pass, and interactions between the substrates and the fill were limited (at most) to that layer. For the refractory metals, the fill only appeared to wet the surface, with minimal dilution effects. Microstructures of the deposits showed high weld metal integrity with maximum porosity on the order of a few percent. Some limited success was also obtained with MPW. In these trials, only the T-111 tubes were used. Joints were possible for the T-111 tube to the Hastelloy X bar stock, but the stiffness of the tube (resisting collapse) necessitated the use of very high power levels. These power levels resulted in damage to the equipment (concentrator) during welding. It is of note that the joint made showed the typical wavy bond microstructure associated with magnetic pulse/explosion bond joints. Joints were not possible between the T-111 tube and the MarM 247 bar stock. In this case, the MarM 247 shattered before sufficient impact forces could be developed for bonding.

No associations

LandOfFree

Say what you really think

Search LandOfFree.com for scientists and scientific papers. Rate them and share your experience with other people.

Rating

Preliminary Investigations of Joining Technologies for Attaching Refractory Metals to Ni-Based Superalloys does not yet have a rating. At this time, there are no reviews or comments for this scientific paper.

If you have personal experience with Preliminary Investigations of Joining Technologies for Attaching Refractory Metals to Ni-Based Superalloys, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Preliminary Investigations of Joining Technologies for Attaching Refractory Metals to Ni-Based Superalloys will most certainly appreciate the feedback.

Rate now

     

Profile ID: LFWR-SCP-O-1283618

  Search
All data on this website is collected from public sources. Our data reflects the most accurate information available at the time of publication.