Fort Wayne Metals - Technical Blog

Braided wire: Balancing size and strength to optimize medical device performance

Thu, 03 Sep 2026 12:00:00 Z

The webinar highlights several recent developments aimed at helping medical device manufacturers address the growing demand for smaller, stronger, and more reliable devices. The presentation covers stainless steel round wire, ultra-strength material offerings, multi-end spooling capabilities, flat wire products, and advanced surface finish options. With capabilities ranging from 0.0127 mm to 13.97 mm [0.0005 in to 0.55 in] diameter wire, Fort Wayne Metals continues to support applications across guidewires, braids, catheters, strands, cables, and other critical medical device components.

A major focus of the webinar is the development of ultra-strength materials, including both 304V stainless steel and tungsten. These materials were created to help customers maintain mechanical performance as devices continue to shrink. Ultra-strength 304V can achieve tensile strengths approaching 500 ksi while maintaining useful ductility, offering potential benefits for catheter reinforcement, guidewires, springs, braids, and cable constructions. Ultra-strength tungsten delivers even higher performance, reaching tensile strengths above 800 ksi and approaching 1 million psi in certain ultrafine diameters. These enhanced properties can help improve stiffness, wear resistance, fatigue performance, and resistance to deformation in demanding applications such as surgical robotics, catheter systems, and chronic total occlusion guidewires.

The webinar also explores manufacturing and processing capabilities that support advanced devices. Multi-end spooling allows up to nine wire ends to be wound onto a single braider bobbin, helping improve braiding efficiency while reducing downtime. Additionally, Fort Wayne Metals highlights its flat wire portfolio, including both rolled and drawn flat wire options, along with multiple surface finishes designed to support specific performance requirements.

Bright, semi-bright, rough-rolled, hybrid, and wet-blasted surfaces can help optimize coating adhesion, braiding performance, handling characteristics, and manufacturability. Together, these capabilities demonstrate Fort Wayne Metals’ commitment to providing not only raw materials, but also engineered wire solutions that help customers improve device performance, streamline manufacturing, and support next-generation medical device innovation.

Advanced coatings and laser ablation for high-performance materials in medical devices

Mon, 24 Aug 2026 12:00:00 Z

Medical device conductors often need to perform multiple functions within a single assembly. One section may need to transmit electrical signals, another must move smoothly through a lumen, and another may require direct contact with tissue. Advanced coating technologies help meet these competing demands by providing electrical insulation, reducing friction, improving durability, or combining several benefits in the same device. Materials such as ETFE, PFA, FEP, PTFE, and polyimide each offer unique performance characteristics that allow engineers to balance dielectric strength, flexibility, lubricity, abrasion resistance, and size constraints based on application requirements.

Selecting the right coating is only part of the solution. Many medical devices require coatings to be removed at specific locations to allow for welding, sensing, stimulation, or electrical connections. Laser ablation provides a precise, non-contact method for removing coatings without damaging the underlying conductor. Unlike traditional mechanical stripping, laser ablation minimizes the risk of conductor damage while enabling highly controlled exposure windows along a wire’s length. This capability supports advanced device designs, including multi-electrode configurations and complex conductor geometries used in neurostimulation, diagnostic, and catheter-based applications.

The greatest value comes from combining coating technologies and laser ablation strategies to match the functional demands of each section of a medical device. For example, conductors may use dielectric coatings for insulation, lubricious coatings to improve device navigation, and selectively ablated regions for electrode contacts or terminations. By tailoring polymer selection, coating thickness, and exposure locations, engineers can optimize device performance while meeting demanding anatomical and functional requirements. Fort Wayne Metals partners with device designers to evaluate these trade-offs and develop coating and ablation solutions that support next-generation medical technologies.

Optimizing medical devices: The effect of platinum on Nitinol DFT® composite wire

Fri, 16 May 2025 10:45:40 Z

The medical device industry is constantly innovating to create smaller, more effective tools that improve patient outcomes. Among these advancements is the development of Nitinol DFT® wire with a platinum core, a material combining the superelastic properties of Nitinol with the radiopacity of platinum. This breakthrough, now two decades running, enables enhanced imaging visibility and mechanical performance, addressing critical challenges in designing minimally invasive medical devices.

Enhancing performance: The role of platinum in Nitinol alloys

Superelastic Nitinol is a preferred material in medical applications due to its shape memory and flexibility. However, the fine diameter of many medical wires reduces visibility under X-ray imaging, a limitation that can hinder precision during procedures. To address this, Fort Wayne Metals developed Nitinol DFT® composite wire, integrating a superelastic Nitinol sheath with a platinum core, and has continued to refine process and material performance since its early 2000s inception. This combination leverages Nitinol’s mechanical advantages and platinum’s radiopacity, creating a wire with properties tailored to medical device specifications.

Key findings: How platinum content affects performance

This study investigated how varying platinum core percentages (10%, 20%, 30%, and 40%) impact the performance of Nitinol DFT® composite wire. The team conducted several tests to evaluate mechanical properties, superelastic behavior, and fatigue performance.

Bend and free recovery: Increasing the platinum content reduced the wire's ability to recover its original shape after deformation. Wires with higher platinum percentages required more energy (heat) to return to their initial form, showing a more sluggish recovery. For example, the "Active Af" (transformation temperature) increased by approximately 6°C for wires with a 40% platinum core compared to solid Nitinol.
Tensile properties: Higher platinum content also decreased tensile and plateau stresses, while increasing residual elongation. This indicates that devices made from wires with larger platinum cores may exhibit reduced expansion forces and less shape recovery after deformation.
Fatigue performance: Despite these changes, platinum content did not significantly affect rotating bending fatigue performance. Both solid Nitinol and composite wires with various platinum percentages achieved over 10 million cycles at low strain levels (0.9%), demonstrating the material’s durability under cyclic loading.

Implications for medical device design

The findings highlight the need to carefully balance radiopacity and mechanical performance when incorporating platinum into Nitinol wires. While a higher platinum core improves visibility under imaging, it also compromises some of Nitinol’s hallmark superelastic properties. Designers must weigh these trade-offs depending on the device’s intended application.

For example, cardiovascular stents requiring precise placement under X-ray may benefit from a higher platinum content, prioritizing radiopacity. On the other hand, devices needing exceptional shape recovery, such as certain orthopedic implants, may favor lower platinum percentages to retain Nitinol’s full superelastic potential.

Conclusion

Nitinol DFT® with a platinum core represents a significant step forward in advancing medical device technology. By integrating two complementary materials, it provides a versatile solution for applications requiring both visibility and mechanical precision. As research continues, further refinements in wire composition and processing could unlock even greater performance, paving the way for next-generation medical devices.

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.