Medical implant manufacturers prize alloy for its elasticity, durability and "shape memory."
Nitinol's ability to return to its original shape makes it a material of choice for makers of implantable medical devices like stents, orthopedic staples, dental implants, and fine-grade medical wire.
Pathogen resistance and cleanability are also critical attributes for the medical parts made from this refractory alloy composed of nickel and titanium. This requires a metal finishing process as specialized as Nitinol itself.
Nitinol was discovered in 1959 by the Naval Ordnance Laboratory. Lightweight and heat-resistant, it was used early on in missile nose cones.
Electropolishing gives Nitinol parts the ultrasmooth, ultraclean surface needed for medical devices, but because it is a refractory metal and extraordinarily resistant to heat and wear, it requires a chemical bath in a dedicated work cell environment. It's a process developed in collaboration between a Chicago-based electropolishing specialist and the Fermi National Accelerator Laboratory.
A Process with Roots in a National Laboratory
In 2008, Fermi partnered with Able Electropolishing to develop a process for electropolishing refractory metal parts of the International Linear Collider. The result was a high-shine finish to an internal cavity in a collider component, and the proprietary process for electropolishing refractory metals like Nitinol that Able has continued to improve over the years.
Today, advanced processes for electropolishing Nitinol parts are specified by a wide array of medical device manufacturers. Electropolishing eliminates burrs and surface imperfections from Nitinol parts with a level of precision and repeatability that other finishing processes cannot match.
Other benefits of electropolishing include improved corrosion resistance--with 30 times more corrosion resistance than passivation alone--the inhibition of pathogen growth and an ultrasmooth finish that enhances cleanability.
Precise Material Removal & Consistent Results for Nitinol Parts
For implantable medical devices, such as finely meshed Nitinol stents, electropolishing's ability to remove a precise amount of material with consistent results makes it the ideal finishing process, leaving intricate parts more durable, cleanable, and with improved fit, function, and appearance.
Nitinol electropolishing is a highly controllable process that creates a uniform, ultrasmooth finish within a very small diameter, leaving the smallest interior cavity free of defects or surface residues left by other processes.
Compliance with Demanding Industry Standards
The best results for electropolishing Nitinol are achieved through carefully tested processes and rigorous compliance with industry standards.
From medical devices and laboratories, to aerospace, pharmaceuticals and food manufacturers, Nitinol parts serve as components in products with little margin for error.
Electropolishing providers that specialize in finishing such parts must be ISO 13485-certified and often work closely with clients to design processes that deliver the best results for their parts, every time. This can include consulting during the prototyping and design phase to identify and prevent issues that negatively affect cleanability and finishing outcomes.
Exacting processes and chemical mixes customized by alloy and metal type, along with custom tooling and prototyping on full production equipment, are also characteristic of the best electropolishing providers.