Titanium alloys used in additive manufacturing often cool and bond together in column-shaped crystals during the 3D printing process, making them prone to cracking or distortion. And unlike aluminum or other commonly used metals, there is no commercial grain refiner for titanium that manufacturers can use to effectively refine the microstructure to avoid these issues.
Researchers created a new titanium alloy with copper that prints without any special process control or additional treatment and features a fully equiaxed grain structure — the crystal grains grow equally in all directions to form a strong bond rather than growing in columns, which can lead to weak points prone to cracking. Alloys with this microstructure can withstand much higher forces and will be much less likely to have defects such as cracking or distortion during manufacture.
Similar metal systems could be treated in the same way to improve their properties. Titanium-copper alloys are one option, particularly if the use of other additional alloying elements or heat treatments can be employed to improve the properties further but there are also a number of other alloying elements that are likely to have similar effects. These could all have applications in the aerospace and biomedical industries.
The new alloys could increase manufacturers’ production rates and allow for more complex parts to be manufactured; a new range of titanium-based alloys can be specifically developed for 3D printing with exceptional properties.