The foundational principles underlying Severe Plas

The foundational principles underlying Severe Plastic Deformation (SPD) and Ultrafine Grained (UFG)metals and alloys have been developed over the past 25 years, as highlighted by multiple excellent overviews. Alloy systems based upon aluminum, copper, magnesium, iron, titanium have been thoroughly explored to elucidate the mechanisms by which SPD imparts desirable UFG microstructures and associated properties, including high strength and ductility. Computational models of thermomechanical deformation, some including microstructure evolution, have been developed to guide SPD process specification to produce UFG metals and alloys. Over 60 variants of SPD processing methods have been published or patented. These advancements support the prospect of industrial production of UFG metals and alloys.
Commercial offerings of UFG metal products are presently few in number. Notable examples include the use of ECAE® by Honeywell in the USA to produce aluminum and copper sputtering targets. Another example is production of Grade 4 titanium rods by NanoMet in Ufa, Russia for the fabrication of Nanoimplant® dental implants by Timplant in the Czech Republic.
The advantages of UFG metals and alloys merit manufacture for additional applications. However, for each prospective product application, appropriate SPD processing must be developed. For the examples of aluminum, copper, and titanium products cited above, several years of process development, equipment optimization, and product inspection technologies were undertaken.
However, with the larger knowledge base now available on microstructures and techniques for SPD, the time needed to develop new products can be shortened.
Nevertheless, systematic progression through sequential manufacturing readiness levels (MRLs),
Phase 1 : Technology Assessment
MRL 1 : Concept proposed with scientific validation
MRL 2 : Application and validity of concept demonstrated
MRL 3 : Experimental proof of concept complete
MRL 4 : Production validation in lab environment
Phase 2 : Pre-production
MRL 5 : Basic capability demonstrated
MRL 6 : Process optimized for production rate / equipment
Phase 3 : Production Implementation
MRL 7 : Capability and rate confirmed
MRL 8 : Production qualified for a full range of products
MRL 9 : Full production qualified against performance metrics
The majority of contributions to the archival literature on SPD appear to pertain to aspects of UFG
metals outside the scope of manufacturing. Even as new SPD methods are proposed, their development and publication generally falls within MRLs 1, 2, and 3. Only in a few instances, for example, Levashov et al. are developments above MRL 4 reported.
Yet, for reproducible manufacturing of UFG metals, SPD methods and their ancillary processes must all be developed through level 9.
A Nanostructured Metals Manufacturing Testbed (NMMT) has been established to enable research and development up to MRL 8.
The NMMT contains four progressively larger and increasingly sophisticated machines for SPD. These machines allow development of SPD parameters and demonstration of pilot scale production for a wide range of alloys. The sections that follow highlight areas that are being addressed in the NMMT for pre-commercial development and pilot-scale production of iron, titanium, aluminum, magnesium, copper, and zirconium based alloys.