Titanium is an extremely strong metal used to make aerospace, medical and other mission-critical parts. It boasts a high strength-to-weight ratio, corrosion resistance, high operating temperatures (up to 1,000°F), and non-toxicity. These material properties are used in parts including orthopedic implants, dental implants and surgical equipment.
In orthopedic applications, titanium might be chosen because some patients are sensitive to cobalt or chromium. However, it has less shear strength than CoCr, and therefore might be unsuitable for very heavy or athletic patients. Surgeons often prefer titanium for knee and shoulder replacements, as well as spinal cages, bone screws, cardiovascular devices, and other implantable, due to its biocompatibility profile.
Commercially pure titanium is considered the most biocompatible, but it is not as strong as alloyed titanium. It is used most often to make dental crowns and bridges, which are then coated with porcelain. It’s also used in fiber metal, a porous material bonded to the surface of an implant to improve osseointegration.
The workhorse alloy is Ti 6-4 (6 percent aluminum and 4 percent vanadium). It boasts light weight, high strength and temperature and corrosion resistance. It is similar to cobalt chromium and is often used in similar applications.
One key drawback for titanium is the price. The raw material is more expensive than steel; many manufacturers don’t hold a lot of inventory. Some contract organizations do, however, maintain an inventory to enable on-demand milling and turning. Check with your supplier, if that is a need you anticipate.
Titanium can be machined via 5-axis milling. The process is well suited for needs such as off-axis hole drilling, complex geometries and finishing non-orthogonal surfaces.
It can also be manufactured via 3D printing, using direct metal laser sintering. DMLS uses a powerful optic laser in a building chamber to fuse titanium powder into a solid part. Layer by layer, the machine builds the object, usually at 20 micrometers of material per layer. The accuracy of the DMLS process results in durable and detailed objects with desired surface qualities.
One benefit for 3D-printing titanium is that the cost and time efficiency of the process reduces the need for test materials. Consideration is still needed for size, surface finish and feature details, similar to any AM process. It is crucial to plan through the building process in advance, and understand post build processes that might be required, such as finishing.