Vitallium or vitalium is an alloy made of cobalt, chromium, and molybdenum. It is notably resistant to corrosion. It is a biomaterial used to make surgical tools and prosthetic implants such as joint replacements.
The exact composition of vitallium alloys depends on their manufacturer. ISO standards define "cobalt chromium molybdenum casting alloy" as containing 26.5% to 30% chromium, 4.5 to 7% molybdenum, and the remainder cobalt. The Medical Subject Headings dictionary defines vitallium as containing 60% cobalt, 20% chromium, 5% molybdenum.
Small amounts of other ingredients can be added to alter its structure and properties.
Vitallium was developed in the United States in 1932, and used in joint replacement. A vitallium implant given to English engineer Norman Sharp at age 23 was recognised as the world's longest-lasting hip replacement in 2016.