Arizona-based startup Rosotics has entered the fabrication and testing phase of a U.S. Navy-backed project to develop large-scale additive manufacturing (AM) capabilities for naval-grade steel components. The initiative aims to validate whether Rosotics’ proprietary Reelement system can produce structural parts suitable for maritime defense applications—potentially altering how ships and subsystems are built and maintained.
From Concept to Fabrication: A Milestone in Naval AM
Rosotics announced on May 30, 2024, that it had transitioned from design into the fabrication and testing stage of its naval steel additive manufacturing program. This milestone follows a successful design validation phase under a Cooperative Research and Development Agreement (CRADA) with the U.S. Navy’s Naval Surface Warfare Center (NSWC), Crane Division.
The project focuses on producing high-strength steel parts using Rosotics’ Reelement system—a proprietary large-scale metal additive manufacturing platform based on a novel form of directed energy deposition (DED). Unlike powder-bed fusion or wire-fed DED systems, Reelement uses a coil-fed metal feedstock combined with electromagnetic heating to deposit material layer by layer at scale. The process is designed to reduce cost, improve safety (by avoiding powders), and operate without inert gas shielding.
This approach could be particularly advantageous in naval contexts where logistical constraints favor on-demand production of large or custom parts near operational theaters or at sea.
Why Naval Steel Is a Complex AM Challenge
Naval-grade steels such as HY-80 or HSLA-100 are prized for their strength-to-weight ratio, fracture toughness, and corrosion resistance—critical properties for hull structures and pressure vessels in submarines or surface combatants. However, these steels are notoriously difficult to weld or print due to their metallurgical behavior during thermal cycling.
Additive manufacturing introduces complex thermal gradients that can lead to cracking, residual stress buildup, or undesirable phase transformations in high-performance steels. Overcoming these challenges requires precise control over heat input, cooling rates, and microstructure evolution—areas where Rosotics claims its Reelement system has an edge due to its electromagnetic-based energy delivery mechanism.
If successful, this project could demonstrate that large-format AM is viable not just for prototyping but also for end-use structural components in demanding naval environments—a leap beyond current applications limited mostly to brackets or non-critical parts.
Reelement System: Scalable Metal AM Without Powders
The core innovation behind Rosotics’ offering is its Reelement additive manufacturing platform. Unlike traditional powder-bed fusion systems that require expensive metal powders and inert gas chambers—or wire-fed DED systems that struggle with resolution—the Reelement system uses coil-fed solid metal feedstock shaped via an electromagnetic field into controlled deposition paths.
- No powders: Eliminates explosion risks and reduces material costs.
- No inert gases: Simplifies deployment in austere environments like shipyards or forward bases.
- Large build envelope: Enables fabrication of meter-scale components such as structural beams or bulkheads.
This makes the technology particularly suited for defense logistics use cases where part availability must be ensured under constrained conditions—such as during extended naval deployments or at remote repair facilities. The company claims deposition rates up to several kilograms per hour depending on material type and geometry complexity.
Navy Collaboration Signals Strategic Interest
The CRADA with NSWC Crane indicates growing U.S. Navy interest in maturing additive technologies beyond lab-scale demonstrations. NSWC Crane specializes in expeditionary warfare systems and advanced manufacturing R&D; partnering with startups like Rosotics allows rapid exploration of disruptive technologies without full procurement commitments upfront.
This aligns with broader Department of Defense (DoD) initiatives under the Office of the Secretary of Defense’s Manufacturing Technology Program (ManTech) aimed at enhancing distributed manufacturing capabilities across services. In particular:
- The U.S. Navy’s Additive Manufacturing Vision 2030 outlines goals for fleet-wide adoption of certified AM parts by end-of-decade timelines.
- The Joint Additive Manufacturing Model Exchange (JAMMEX) platform is being developed to standardize digital part files across DoD users.
If Rosotics’ technology proves viable through this CRADA pathway—including metallurgical testing against MIL-STD requirements—it could pave the way toward qualification pipelines via NAVSEA’s Technical Warrant Holder process for shipboard use cases.
Implications for Shipbuilding and Sustainment
Additive manufacturing has long been touted as a game-changer for military logistics—but scaling it up from polymers to mission-critical metals remains a work in progress. If Rosotics can demonstrate reliable printing of naval-grade steel structures at scale:
- Sustainment: Fleet maintenance could shift from centralized depots toward more distributed repair hubs—even aboard ships equipped with compact AM units.
- Shipbuilding agility: Custom-fit structural elements could be produced faster than traditional casting/fabrication cycles allow—especially useful during surge construction periods or battle damage repair scenarios.
- Spares reduction: Digital inventories could replace physical stockpiles onboard vessels if validated part geometries can be printed on demand within MIL-SPEC tolerances.
This would mirror trends already underway in aerospace sectors where companies like GE Aviation have certified flight-critical printed titanium components—and push similar innovation into maritime domains traditionally slower to adopt new materials tech due to harsh operating conditions and stringent standards compliance requirements.
Next Steps: Testing Against Military Standards
The current phase will involve fabricating test coupons and full-scale demonstrator parts using HY-class steels followed by mechanical characterization including tensile strength, impact toughness (Charpy V-notch), hardness profiles, microstructure analysis via SEM/EBSD techniques—and weldability assessments if hybrid joining is required downstream.
If results meet NAVSEA/NAVFAC criteria under relevant MIL-STD specifications (e.g., MIL-S-16216), further steps may include environmental exposure testing such as salt fog corrosion trials per ASTM B117 protocols—and eventual onboard trials aboard non-critical platforms like auxiliary vessels before frontline deployment authorization is considered.
A Broader Trend Toward Agile Defense Manufacturing
This project reflects growing momentum around agile production methods across NATO navies facing aging fleets amid constrained budgets. Other efforts include BAE Systems’ use of metal AM at Portsmouth Naval Base (UK), Australia’s investment into AML3D’s wire arc additive systems for submarine sustainment needs—and DARPA’s TRADES program exploring topology-optimized structures printable via novel processes like cold spray deposition or friction stir AM techniques.
In this context, Rosotics’ entry into full-scale fabrication marks not just a technical milestone but also signals potential disruption within military-industrial supply chains increasingly shaped by digital design tools and adaptive production workflows capable of responding faster than legacy procurement cycles allow today.
Conclusion
The transition by Rosotics into fabrication/testing marks a pivotal step toward validating scalable metal additive manufacturing solutions tailored specifically for naval-grade steel applications—a domain historically resistant to change due to performance-critical demands. If successful through metallurgical qualification phases now underway with NSWC Crane support, this effort may open doors toward more agile sustainment models across future fleets while reshaping how navies think about shipbuilding resilience amid evolving threat landscapes.
