Solid-state processing is changing how the aerospace, defense, energy, and advanced manufacturing sectors approach high-performance metal parts and materials. Two technologies attracting growing attention are friction extrusion (FE) and additive friction stir deposition (AFSD).
Although FE and AFSD are distinct processes, FE could support the continued development of AFSD in important ways. Its clearest complementary role is producing wire, rod, and other extruded material forms, including feedstock made from recycled or engineered materials. FE also provides a platform for materials research that can expand the broader understanding of friction-based solid-state processing.
What Is Friction Extrusion?
FE is a solid-state process in which a rotating die is pressed against a stationary billet, or a rotating billet is pressed against a stationary die.
In friction extrusion, frictional heat and shear deformation soften the material, which is forced through a die to produce wire, rod, tube, bars, or other extruded forms.
Because the material maintains a temperature below its melting point, FE is a single process that can achieve material consolidation, severe plastic deformation, grain refinement, and reshaping.
Originally developed at The Welding Institute (TWI) in the early 1990s, FE has continued to advance through research at national laboratories, universities, and organizations working in solid-state materials processing.
FE has demonstrated the potential to:
- Consolidate machine chips, powders, and other material into usable wire, rod, or other extruded forms without a conventional remelt step.
- Produce significant grain refinement and unique microstructures that can enable properties difficult to achieve through conventional processing.
- Process challenging alloys and material systems, including high-performance aluminum, magnesium, titanium, and other metals.
- Produce metal matrix composites and engineered materials that can be difficult to manufacture through liquid-phase processes.
- Create specialized feedstock with potential applications in downstream manufacturing processes, including additive manufacturing (AM).
These capabilities make FE particularly interesting for organizations working on material efficiency, alloy development, recycling, and advanced manufacturing.
What Are AFSD and FSAM?
Additive friction stir deposition is a solid-state AM process. Feedstock is introduced through a rotating tool and deposited onto a substrate through frictional heating and severe plastic deformation.
Rather than melting the material, AFSD plasticizes and consolidates it in the solid state. Material is deposited layer-by-layer to build or repair a fully dense component with fine, recrystallized grain structures while reducing exposure to some of the porosity, hot cracking, and residual stress challenges associated with fusion-based AM.
Friction stir additive manufacturing (FSAM) is a broader term used to describe AM approaches based on friction stir principles. AFSD is one process within this growing area of solid-state AM.
How Friction Extrusion Could Support AFSD
FE and AFSD are related technologies, but they address different manufacturing needs.
AFSD can directly upcycle material to build fully dense components or complete repairs, so FE is not required for every AFSD application. The opportunity for FE is complementary: producing larger quantities of extruded material forms, developing specialized feedstock, and supporting research into materials that may eventually be used in solid-state additive manufacturing.
The connection is strongest in feedstock production, materials research, and the broader science behind friction-based solid-state processing.
1. FE Creates New Possibilities for Additive Feedstock
For AFSD applications that use solid feedstock, geometry and material consistency are important considerations. Conventional manufacturing can readily provide feedstock for many applications, but more specialized material systems present additional challenges.
This is where friction extrusion could play an important role.
FE can consolidate machining chips, powders, scrap, and other starting materials into wire, rod, or similar forms without requiring a traditional melt-and-cast cycle. That creates possibilities for producing feedstock from reclaimed material and for developing specialized alloy or composite feedstocks that may be difficult to manufacture conventionally.
Research at Pacific Northwest National Laboratory (PNNL), for example, has demonstrated friction-based processing of materials including titanium, aluminum, magnesium, copper, and other material systems. PNNL has also investigated friction extrusion as a method of converting machining waste into new material, including titanium alloy wire intended for additive manufacturing applications.
For additive manufacturing, the opportunity is significant: instead of viewing feedstock only as a standardized input, FE creates the possibility of engineering the feedstock itself as part of the manufacturing strategy.
2. FE Provides a Platform for Advanced Materials Research
Before a new alloy, composite, or feedstock strategy reaches production, engineers need to understand how the material responds to heat, force, deformation, and processing speed.
FE provides a highly controlled environment for investigating those relationships.
PNNL’s Shear Assisted Processing and Extrusion (ShAPE™) technology is one of the most prominent examples. ShAPE is a specialized FE approach that has been used to investigate lightweight alloys, recycled materials, high-conductivity materials, composites, and other advanced material systems.
Multiple generations of ShAPE equipment have been built by Bond Technologies for PNNL, including ShAPE 1, ShAPE 2, and the highly configurable ShAPEshifter system.
ShAPE 2 significantly expanded the scale and complexity of the extrusions researchers could investigate, while ShAPEshifter was engineered to support specialized materials research, including the extrusion of brittle materials into extremely small-diameter wire.
Bond’s FE100 platform has also been used in independent peer-reviewed FE research, extending the technology’s role into the broader materials research community.
This work contributes to a growing understanding of how materials behave under severe plastic deformation — knowledge that is relevant across many friction-based solid-state processes.
3. FE and AFSD Share Important Engineering Questions
FE and AFSD use different machine architectures and produce different outputs, but engineers working with the two processes encounter many familiar questions.
How do force and torque affect material flow? How does processing temperature influence grain structure? How does tool geometry change deformation? How do processing speed and material composition affect the final properties?
These questions matter across friction-based solid-state processing.
Successful deposition or extrusion requires researchers to adjust process parameters and confirm that the resulting components behave as expected. Although the machine capability exists, neither process offers a single push-button solution. Both depend on careful process development, and the equipment provides a platform for expanding material and process understanding.
Advances in understanding one process can therefore contribute to the broader body of knowledge surrounding thermomechanical processing, severe plastic deformation, material flow, microstructure development, and process control.
For research organizations in particular, this shared materials science makes FE an important part of the larger conversation around solid-state manufacturing.
Why This Matters for Aerospace, Defense, and Energy
These solid-state processes are especially relevant to aerospace, defense, and energy programs, where material performance, weight, supply-chain resilience, and manufacturing efficiency can influence program success.
Depending on the process and application, potential benefits include refined microstructures, the ability to work with certain challenging material systems, reduced exposure to issues associated with melting and resolidification, and opportunities to reuse machining waste without a traditional remelt cycle.
For organizations evaluating AFSD or another solid-state additive process, FE may provide a complementary platform for producing extruded material forms, investigating new material systems, and developing specialized feedstock.
The Opportunity for Multi-Material and Engineered Feedstock
One of the most interesting areas of friction extrusion research is its ability to process materials that are difficult to produce through conventional melt-based manufacturing. That includes metal matrix composites, recycled material streams, and combinations of materials designed to achieve specific properties.
Instead of starting with an existing commercial alloy and asking what can be manufactured from it, engineers can begin with a different question:
What should the material itself look like for this application?
That opens possibilities for feedstock engineered around conductivity, strength, weight, corrosion resistance, thermal performance, or other application-specific requirements.
For friction-based AM, these developments could eventually expand the range of materials available for deposition and create new opportunities for functionally engineered components.
Where Standards Sit Today
Unlike friction stir welding, which has established standards including AWS D17.3 for aerospace applications and ISO 25239 for aluminum, FE and AFSD are earlier in their standardization journey.
ASTM International’s Additive Manufacturing Center of Excellence and ASTRO America, for example, launched an initiative focused on advancing AFSD standards, quality infrastructure, and industry best practices.
Continued development of standards will be an important step toward broader adoption of these technologies in production environments.
What to Watch Next for FE and AFSD
Future adoption will depend on continued progress in feedstock economics, engineered materials, equipment scale, and qualification pathways. Together, those developments will help determine where FE can most effectively support AFSD and other friction-based additive manufacturing programs.
These developments will help determine how friction extrusion and friction-based additive manufacturing evolve.
Feedstock economics and material efficiency. Research into converting machining waste and other material streams directly into usable feedstock could create new opportunities to reduce processing steps, energy use, and material waste.
Engineered and multi-material feedstock. FE’s ability to process composites and unconventional material combinations creates opportunities to develop feedstock around specific mechanical, electrical, thermal, or corrosion requirements.
Larger-scale applications. As solid-state processing equipment grows in size and capability, the range of parts, materials, and production volumes these technologies can address will continue to expand.
Standards and qualification. Continued work by ASTM, AWS, ISO, government laboratories, industry, and academic researchers will help establish the qualification pathways needed for broader production adoption.
The technologies are still developing, but the direction is clear: solid-state processing is giving engineers new ways to think about not only how metal parts are manufactured, but how the material going into those parts can be created and engineered.
Talk to Bond About Your Friction Extrusion Program
Bond Technologies designs and builds friction extrusion equipment for organizations advancing solid-state materials research and manufacturing.
From dedicated friction extrusion platforms to highly specialized research systems developed for national laboratory applications, Bond combines machine design, controls, tooling, process knowledge, and friction-based processing experience to help customers investigate what is possible with these emerging technologies.
If you are evaluating friction extrusion for alloy development, recycled material processing, specialized feedstock, or a broader solid-state manufacturing program, talk with Bond about your application and what a purpose-built FE platform can support.
Related Research
- “Experimental–Numerical Investigation of Force-Controlled Friction Extrusion Process via Feedback-Controlled Simulation” — Advances in Industrial and Manufacturing Engineering (2026). Experimental work using the Bond Technologies FE100, including process-force and temperature analysis during friction extrusion of AA7075-T6.
View the study on ScienceDirect - “Effect of Consumable Stud Microstructure on Friction Surfacing: Comparison Between Friction Extruded and Hot Extruded AA2024 Studs” — Journal of Materials Processing Technology (2025). Examines friction-extruded AA2024 material produced using a Bond Technologies FE100 and subsequently used in another solid-state friction process.
View the study on ScienceDirect - “Efficiency and Microstructural Forecasts in Friction Stir Extrusion Compared to Traditional Hot Extrusion of AA6061” — Journal of Manufacturing and Materials Processing (2024). Investigates friction-based consolidation of AA6061 powder using a Bond Technologies FE100, including resulting microstructure and process efficiency.
View the peer-reviewed study - “Friction-Based Recycling: Evaluation of Friction Extrusion for Fabricating Ti-6Al-4V Wire” — Pacific Northwest National Laboratory. Evaluates friction extrusion as a way to convert Ti-6Al-4V machining waste into wire for additive manufacturing applications.
View the PNNL research
