Fort Wayne Metals - Technical Blog

How advanced processing is revolutionizing tungsten performance

Thu, 10 Jul 2025 15:08:36 Z

Tungsten is a material known for its exceptional hardness, high melting point, and resistance to wear. These properties make it indispensable in industries like aerospace, robotics, and industrial manufacturing. However, the performance of tungsten depends heavily on how it is processed.

Traditional tungsten processing methods, such as warm working and hot-to-warm drawing, have been effective, but come with limitations. These conventional techniques often result in lower tensile strength, increased brittleness, and an inconsistent microstructure. As industries demand higher performance materials, advanced processing techniques have emerged to significantly enhance tungsten’s mechanical properties.

Advancements in high-strength tungsten processing

Fort Wayne Metals has developed an innovative processing technique that significantly enhances tungsten’s performance. Through a series of mechanical treatments, this method increases the ultimate tensile strength by over 30% while also improving ductility and structural consistency.

Key advantages of this high-strength processed tungsten include:

Enhanced tensile strength – The material can withstand significantly greater mechanical stress, reaching tensile strengths exceeding 6 GPa.
Improved ductility – Even at small diameters, this tungsten remains more ductile, reducing the risk of brittle fractures.
Uniform grain structure – The refined microstructure ensures consistent properties across long material lengths, enhancing reliability in demanding applications.

Comparing high-strength and conventionally processed tungsten

Figures from recent testing illustrate the stark differences between conventional and high-strength processed tungsten. When comparing 25 µm (0.001 in) wire, Fort Wayne Metals’ advanced tungsten exhibited strength improvements from approximately 4 GPa to 5.5 GPa. Additionally, the work energy to fracture—an indicator of material toughness—more than tripled from 40 to 125 mJ/mm³.

Further process refinements and diameter reduction to 12 µm (~0.0005 in) have yielded even more impressive results, with strength reaching nearly 6.8 GPa (1 million psi). These properties suggest significant benefits for applications where structural fatigue performance is critical, such as robotic manipulation.

The future of tungsten in high-performance applications

With its superior mechanical properties, high-strength processed tungsten is set to play a crucial role in next-generation technologies. Fort Wayne Metals continues to push the boundaries of tungsten processing, with ongoing research into structural fatigue durability and total applied performance. As industries evolve, materials like high-strength tungsten will be essential in meeting the increasing demands for reliability and efficiency.

Advancing neurovascular treatment: FeMnN—Mo composite wires for absorbable flow Diverters

Mon, 06 Feb 2023 14:35:00 Z

The growing demand for innovative solutions to treat intracranial aneurysms has driven advancements in medical materials. Researchers at Fort Wayne Metals have developed FeMnN-Mo composite wires as a foundation for absorbable flow diverters. These devices, designed to treat aneurysms by redirecting blood flow and promoting clot formation, are expected to dissolve after achieving their purpose, reducing long-term complications.

Challenges with existing materialsExisting flow diverters employ permanent metals such as 35N LT® or Nitinol. These devices function well but are unnecessary after aneurysm occlusion and can impede secondary procedures. Absorbable polymers like polyglycolic acid (PGA) and poly-l-lactic acid (PLLA) have been investigated as temporary options but require larger struts for sufficient strength, compromising device profile and flexibility. Absorbable Mg- and Fe-based devices have also been investigated but suffer from rapid degradation and premature fracture.

Innovative FeMnN-Mo composite wiresThe study introduces composite DFT® wires made of:

FeMnN shell: Provides strength, elasticity, and a cell-friendly surface.
Molybdenum (Mo) core: Offers enhanced radiopacity and staged corrosion protection.

These wires, available in diameters as fine as 25 µm, mimic the dimensions of traditional metallic flow diverters while addressing their limitations.

Key findings

Mechanical performance

The composite wires achieved mechanical properties comparable to non-absorbable counterparts, with customizable strength and elasticity by varying Mo content.
Braided prototypes demonstrated crush resistance similar to commercial devices, making them suitable for neurovascular applications.

Enhanced radiopacity

The Mo core significantly improved visibility under fluoroscopic guidance, essential for precise device placement.
Radiopacity increased proportionally with Mo content, ensuring adequate imaging performance without permanent markers.

Corrosion Behavior

In vitro and in vivo tests showed progressive and controlled degradation of the FeMnN shell, while the Mo core remained intact for at least six months.
This staged degradation minimizes the risk of premature fragmentation.

Biocompatibility

Cytotoxicity testing confirmed minimal impact on cellular health, supporting the material's safety for clinical use.

Advantages for Neurovascular Devices

Minimized profile: Comparable to traditional flow diverters, enabling easier navigation in small vessels.
Reduced long-term risks: Absorbability eliminates concerns like chronic inflammation, side branch blockage, and imaging artifacts from permanent implants.
Improved healing: Supports endothelial tissue regeneration over aneurysm necks for effective occlusion.

Future Directions
While these findings highlight the potential of FeMnN-Mo DFT® composite wires, further research is needed to optimize their degradation timeline and assess long-term clinical performance. Exploring additional configurations and alloy combinations could further enhance their functionality.

Conclusion
FeMnN-Mo DFT® composite wires represent a promising step forward in the development of absorbable flow diverters. By addressing critical challenges in material performance and compatibility, this innovation paves the way for safer and more effective neurovascular treatments.

Super-elastic alloys with gigapascal plateau strengths: Advancing medical and space applications

Thu, 04 Mar 2021 12:00:00 Z

Nitinol alloys have long been a core material in medical and industrial applications due to their unique super-elastic properties. Fort Wayne Metals developed a new generation of Nitinol-based super-elastic (SE) alloys that push the previous boundaries of strength and performance. With upper plateau strengths exceeding 1.0 GPa and lower plateau strengths above 600 MPa, these advanced materials unlock new possibilities across a range of demanding applications.

Enhanced strength for medical applications

The ability to achieve high plateau stresses allows medical device engineers to develop components with thinner profiles while maintaining or even increasing mechanical performance. For instance, vascular guidewires and orthodontic arch wires made from these advanced Nitinol alloys can deliver greater force in smaller wire diameters.

Tensile stress-strain testing of one such alloy, NiTiNbY, revealed remarkable improvements over traditional binary Nitinol alloys. NiTiNbY demonstrated a forward loading plateau stress of 1100 MPa—an increase of more than 65% compared to conventional Nitinol’s 650 MPa. Additionally, its unloading plateau stress is double that of standard Nitinol, while its axial elastic modulus is 40-50% higher. These improvements mean that medical devices, such as stents and guidewires, can be designed with thinner structures without compromising outward force or performance.

While higher stresses can enhance push-ability and torque in guidewires, engineers must consider durability, particularly for permanent implants. However, for temporary devices, the benefits are substantial. Orthodontic arch wires, for example, can provide double the bending force compared to traditional Nitinol wires, enhancing treatment efficiency.

Superelasticity at cryogenic temperatures for space applications

One of the most remarkable attributes of these alloys is their ability to retain super-elastic properties even at extremely low temperatures. Traditional Nitinol alloys transform to martensite upon cooling, losing their super-elastic behavior. However, NiTiNbY and similar compositions maintain stable super-elastic recovery even at -130°C, as shown in stress-strain testing. This property makes them ideal for applications in space exploration and other extreme environments.

Potential space applications include deployable structures, springs, and even advanced tire designs for extraterrestrial exploration. A spring or textile-based tire made from NiTiNbY alloy could be compacted for transport and then deployed to operate over a broad temperature range while maintaining high load-carrying capabilities.

If you are interested in the future of Nitinol alloy spring tires and our collaboration with NASA, please explore our most recent research.

The challenge of finding a Nitinol alternative

Mon, 23 Nov 2020 15:09:00 Z

Nitinol has long been the material of choice for medical devices that require super-elasticity. Its ability to recover from deformation without permanent damage makes it essential in applications like stents, guidewires, and orthopedic implants. However, concerns over Nitinol’s nickel content with potential allergic reactions from patients have driven research into alternative materials with comparable properties.

The rise of Ni-free β-Ti alloys

One promising alternative is a Ni-free β-Ti alloy composed of Ti-40Hf-13Nb-4.5Sn (wt.%). This alloy demonstrates large and stable super-elastic behavior at room temperature, a key requirement for medical applications. Unlike other β-Ti alloys that struggle to achieve the recoverable strain of Nitinol, this material exhibits up to 5.3% total recoverable strain at 6% deformation—putting it much closer to Nitinol’s performance.

Key advantages of Ti-Hf-Nb-Sn (THNS) alloy

This Ni-free β-Ti alloy offers several advantages beyond eliminating nickel:

Comparable mechanical properties: Its mechanical strength and fatigue performance are in the same range as superelastic Nitinol.
Customizable plateau strengths: Similar to Ni-rich Nitinol, the alloy's performance can be adjusted through low-temperature aging.
Manufacturability at scale: The alloy has been successfully produced in 100 kg quantities using commercial production lines, making it feasible for industrial-scale applications.
High X-ray visibility: The presence of hafnium enhances radiopacity, which is beneficial for medical imaging during procedures.
Biocompatibility and corrosion resistance: These characteristics make it a strong candidate for implants, especially for nickel-sensitive patients.

Overcoming manufacturing challenges

Many β-Ti alloys have struggled with manufacturability due to high heat treatment requirements and oxidation concerns. However, this alloy achieves optimal mechanical properties at lower temperatures (~600°C), reducing the risk of oxidation and making shape-setting more practical. Unlike other high-zirconium β-Ti alloys, which pose ignition risks during processing, this alloy has demonstrated safer large-scale production capabilities.

A substitute for Nitinol?

Despite years of research, no Ni-free β-Ti alloy has been successfully substituted for Nitinol in the medical device industry—until now. With its stable super-elasticity, comparable mechanical properties, and improved manufacturability, this Ti-Hf-Nb-Sn alloy presents a viable alternative for applications such as orthopedic implants, dental devices, and neurovascular components.

As the medical industry continues to prioritize patient safety and material innovation, this breakthrough may pave the way for the next generation of superelastic biomaterials.