The objective of this NAMII sponsored project is to develop, evaluate and qualify novel methods of rejuvenation and repurposing (RR) using additive manufacturing (AM). A group of experienced professionals is teaming to address this fast paced, industrially oriented project. The payoffs are substantial, and cut across industries. Extending life of tooling means saving a large investment of new capital.
Rejuvenation is done on a worn out or defective tool to continue operating it and extend useful die life. Repurposing is a new concept by which a decommissioned tool is modified with additive and/or substractive manufacturing, to be used in die casting of a similar part. While not exclusively targeted, steel tooling is the immediate area of interest, die and permanent mold casting, forging, rolling, extrusion and oil drilling tools as front runners. The extreme mechanical and thermal demands placed on tooling serve well as demonstration for the capabilities of RR in a broader range of DoD and dual use applications.
Die casting tooling can be very expensive. A large die used in making automotive aluminum blocks and cylinders can cost $1.5M. The die casting industry alone contributes annually about $7 Billion to the US economy. It is estimated about 20% i.e. $1.4 Billion is reinvested in tooling. Repurposing and extending die life by RR has large payoffs and can eliminate or delay the need for building a new die thus making a critical contribution to the affordability of tooling in the US. Industry-wide gains in die lie facilitated by industry wide adoption of rejuvenation and repurposing could be as high as $500 Million/year. Similar gains apply to the forging industry. Currently, tooling repair relies almost exclusively on welding, also an additive method. State of the art TIG, MIG and Laser Welding repair, done according to the appropriate American Welding Society standards and specifications, will be used in this project as a performance baseline.
The new paradigm for rejuvenation and repurposing proposed in this study promotes integrative application of 3D printing, cladding, cold spraying, welding, laser micro-welding, thermal plasma and e-beam welding. The best method or combination of methods for reconstructive repair will be selected on a case-by-case basis. The selection criteria and rationale will be documented in detail and become part of the qualification process.
Of particular interest is the rebuild of small, local net-shape features on large components such as dies or roller rings. In collaboration with equipment manufacturers, the project will design fixtures and methods for fitting sections of large parts inside the next generation of 3D printers.
The project will document in detail the feed materials and process variables used in the RR. The performance of the AM materials will be tested according to ASTM, ASW and MIL specs. The RR tooling will be evaluated in production and the performance compared to new tooling. Whenever possible, multiple cavity dies will be employed, with each insert representing a different rejuvenation method. This will provide an apples-to-apples performance comparison. The findings will be formalized as Specifications for Rejuvenation and Repurposing of specific materials/components, for example, “Rejuvenation and Repurposing of Tool Steel Die Casting Dies” and submitted for consideration standardization bodies i.e ASTM and ASW.