Titanium alloys are the first choice for the manufacture of knee/hip implants
Titanium alloys are the first choice for orthopaedic materials for the manufacture of knee/hip implants. Titanium-tantalum alloys will be able to alleviate the "stress shielding" effect, the so-called "stress shielding" effect is that the hardness of the implant is too high to cause its adjacent Osteoporosis is caused by insufficient mechanical stimulation of the bones. "These alloys are specifically designed for orthopedic applications, and it is even possible that after deformation, they show some kind of shape memory.
There is absolutely no problem with alloys of titanium and tantalum, because both metals are biocompatible and their mechanical properties are due to pure titanium. But tantalum has a very high melting point (over 3000 degrees Celsius), which means that turning titanium into a spherical metal powder that can be used in SLM technology is not economically viable. The common tantalum powder on the market is usually long and rough particles formed by gas atomization. To overcome this problem, the research team mixed the rough tantalum powder with another commercially available microspherical titanium powder. After mixing the two materials for half a day, they observed that the mixture could be spread more evenly, making it easier to use with SLM technology. Microscopic experiments revealed that the spherical shape of the titanium metal remained after mixing, which is the key to the successful use of the mixture for 3D printing.
"The titanium powder acts as a rolling medium here," Wiria explained. "It pushes the tantalum powder and makes the SLM process possible." By alternating a checkerboard pattern of laser scanning to melt the metal up and down or from one side Moving to the other side to reduce thermal stress, the researchers succeeded in producing 3D shapes of titanium-tantalum alloys using SLM technology. Surprisingly, detection by X-ray and other imaging techniques showed that the addition of tantalum metal, coupled with rapid solidification, promoted and stabilized the formation of high-strength layered titanium grains. So far, researchers have mainly used selective laser melting (SLM) technology and titanium-aluminum-based powders to 3D print biological prototypes. SLM technology typically uses high-power lasers to build 3D objects layer by layer from a computer design model. But because aluminum has long-term adverse effects on human nerves, scientists hope to find other materials to replace it.
