A newly approved ASTM standard is expected to advance the use of metal injection molding (MIM) as a manufacturing method for medical implants.

ASTM F2989 is a new international specification that covers unalloyed titanium components that are used for surgical implants. It was developed by Subcommittee F04.12 on Metallurgical Materials, part of ASTM International Committee F04 on Medical and Surgical Materials and Devices.

"Through ASTM F2989, the material properties of metal injection molding (MIM) unalloyed titanium components can be directly compared to components that are made with conventional methods," says Matthias Scharvogel, managing director, Element 22 GmbH, and an F04 committee member.

That's important, says Scharvogel, because Metal Injection Molding (MIM) could reduce costs compared to titanium alloy implants produced via competing methods.

ASTM F2989 will also be used as the basis for laboratories that test the material properties of the metal injection molding (MIM) component. The standard also defines the requirements as a baseline for the regulatory bodies.

ASTM F2989 covers the chemical, mechanical and metallurgical requirements for three grades of metal injection molding (MIM) unalloyed titanium components to be used in the manufacture of surgical implants.

Scharvogel has been working for several years with German research organizations to developing molding grades of titanium alloys that could be formed into complex shapes while  maintaining excellent mechanical properties.

He formed Element22 in 2011 after acquiring TiJet Medizin-technik of Kiel, Germany. Its key asset is a proprietary titanium feedstock. Molding processes have been optimized for the feedstock.

The technology is based partly on projects conducted with Fraunhofer IFAM, Bremen, Germany, and HZG Helmholtz-Zentrum, Geesthacht, Germany. A production line for medical MIM components made from the special titanium was established in 2004.

Advantages of titanium for medical applications include its high strength, low density and corrosion resistance. Scharvogel says that the proprietary molded titanium parts have mechanical properties comparable to wrought titanium.

The titanium implant will compete with engineering plastics, such as polyetheretherketone (PEEK), which are often machined from stock shapes.