Medical-grade investment castings

The healthcare industry constantly evolves, and recent years have seen an increased need for innovations in medical technology and portable, durable devices. Simultaneously, there is growing demand for medical components that are not only high-performing but also compatible with the human body over sustained use.

For many years, stainless steel was considered the only material suitable for manufacturing medical equipment. However, aluminium and cobalt chromium alloys have recently found a place in the medical market.

Signicast investment castings leverage each of these alloys, along with precision capabilities and tight tolerances, for the best performance in the industry.  

Stainless steel alloys for medical-grade equipment

While innovations in materials for the medical industry are ever-changing, stainless steel remains a top choice for most medical equipment manufacturers due to its low- and high-temperature resistance, high strength, and biocompatible properties. Investment casting allows the necessary complex geometries to be engineered into the casting, enhancing part performance and reliability. Signicast's stainless steel alloys include different combinations of nickel, chromium, and carbon. Depending on the application, one can choose between the 300 or the 400 series stainless steels.  

• The 400-series comprises 25% nickel, 1% carbon, and 11-27% chromium.

• The 300-series contains 6-25% nickel and 16-30% chromium.

If high strength and cost reduction are priorities, the 400-series might be the right choice. However, for applications needing high strength, high corrosion resistance, and property retention at high temperatures, the 300-series group could be more effective.

Consulting a Signicast metallurgist is recommended to determine the most suitable material for specific requirements. There may be an option available that has not yet been considered.

Aluminium alloys for Class 1 & 2 devices and housings

While stainless steels meet biocompatibility and strength requirements for Class 1 and 2 medical devices, their weight can be a limiting factor in usability. Aluminium alloys often offer lower total costs while maintaining a significantly higher strength-to-weight ratio compared to stainless steels. Additionally, aluminium inherently creates aluminium oxide when exposed to oxidising agents, forming a protective layer that prevents further oxidation and weakening of the component. This is where lightweight aluminium has found its place in the market, producing medical components for applications such as handheld surgical devices and portable medical equipment that need to be durable, lightweight, and easy to use while also meeting stringent FDA regulations.

Cobalt alloys (ASTM-75) for implantable devices

Signicast has utilised cobalt alloys as an alternative to stainless steel, particularly for implantable devices. Cobalt-Chromium, which is ferromagnetic, is very strong even at very high temperatures and has high corrosion and wear resistance compared to other metals. It is also entirely biocompatible, making it suitable for implantable devices.

Medical component manufacturer

Medical devices, whether Class 1 or 2, have components that should meet and/or exceed the necessary efficiency and safety requirements set by governing bodies, as well as the physical and mechanical properties required by the manufacturer. This calls for extra care when choosing the material for such devices and the right manufacturing partner for a successful programme launch.