Advancing Nitinol from melt to medical device

Thu, 07 May 2026 12:00:00 Z

Recent advances in melting technology, particularly the addition of plasma arc melting (PAM) alongside traditional vacuum arc remelting (VAR), are producing a new generation of Nitinol with improved microstructural control. At the same time, the industry’s first collaborative, multi-company validation effort, the PRIME project, has tested these materials across the full manufacturing chain, from ingot to finished device.

For engineers, the result is clear: today’s Nitinol options are cleaner, more consistent, and supported by significantly more data than in the past.

Why inclusion control matters

One of the most important factors driving these improvements is inclusion control. Fatigue performance in Nitinol is closely tied to crack initiation, which often originates from non-metallic inclusions, such as titanium carbide or oxide particles. Reducing the size and frequency of these inclusions has a direct impact on device durability, particularly in fatigue-critical applications.

This is where newer melting methods stand out. While traditional VAR-processed material meets established ASTM standards, PAM-based processes enable tighter control over inclusion size and distribution. The result of this method at Fort Wayne Metals is Gen II Altus™ Nitinol, which contains a maximum inclusion size of 20 μm and supports the demands of neurovascular stents as well as non-medical applications such as robotic flexures and precision instrumentation.

Validated performance across the supply chain

The PRIME project (prime-ingot.com) provides real-world validation of this progress. Across five independent organizations, spanning melt, tube manufacturing, and device production, multiple generations of Nitinol materials were processed using standard workflows without modification.

The results were consistent: no manufacturing complications, strong mechanical performance, and full compliance with industry standards across multiple device types, including peripheral stents and heart valve frames.

Just as importantly, tube processing itself further reduced inclusion size, demonstrating that downstream manufacturing steps can enhance material cleanliness beyond the starting ingot. This reinforces the idea that melt quality and process control work together to drive final device performance.

What this means for device design

These advancements are not just incremental improvements. They meaningfully expand what engineers can expect from Nitinol:

Improved fatigue performance through smaller, more controlled inclusions
Seamless manufacturability using existing, validated production processes
Greater consistency across suppliers and production lots
Reduced supply chain risk with validated dual-sourcing options
Expanded design flexibility with new alloy variants and material forms

Beyond performance improvements, these advancements also address a longstanding industry concern: supply chain risk. With validated material produced through both VAR and PAM processes, device manufacturers now have viable dual-sourcing options without compromising quality. This added flexibility reduces dependence on a limited number of suppliers and improves overall resilience.

Expanding on what Nitinol can do

Control over the melt process is also unlocking new material possibilities. With greater flexibility in composition and processing, specialized Nitinol variants are emerging to solve specific design challenges, from increased stiffness and pushability to improved radiopacity and reduced friction. These options allow engineers to move beyond standard superelastic behavior and tailor materials more precisely to application needs.

Looking ahead, continued testing, particularly in fatigue performance at the device level, will further quantify the benefits of these advancements. Early results already show equal or improved performance compared to existing materials, reinforcing confidence in next-generation Nitinol.

Taken together, these developments mark a meaningful step forward. Cleaner material, broader supply, and expanded design options are giving engineers more control and more confidence—ultimately creating new opportunities to push the performance of medical devices even further.

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.

Fort Wayne Metals - Technical Blog

Advancing Nitinol from melt to medical device

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

Enhanced strength for medical applications

Superelasticity at cryogenic temperatures for space applications