The quality of 3D-printed metal parts may soon improve thanks to a new study in Australia,media reported. Scientists there have determined that ultrasound can enhance the strength of these materials by altering the microstructure of these materials. The RMIT Team, led by Doctor Al-Carmelo Todaro, recently experimented with an existing 3D printing technique called Directional Energy Deposition (DED).
RmIT researchers are known to print samples using two different common alloys: Ti-6Al-4V, a titanium alloy commonly used in aircraft parts and biomechanical implants, and Inconel 625, a nickel-based high-temperature alloy commonly used in the marine and oil industries.
Regardless of the alloy used, the deposition surface is actually a sonic detector, a tool for generating ultrasonic vibrations. When metal solidified, vibration acts on microcrystallization, resulting in a tighter structure. It was found that the tensile strength and yield stress of these substances increased by 12% compared to the same samples that did not use ultrasound.
“If you look at the microstructures of 3D-printed alloys, they are usually made up of large, slender crystals, ” says Todrao. Due to its low mechanical properties and its susceptible to cracks during printing, this makes them more difficult to accept in engineering applications. However, the microstructure of the alloy selith steamed by ultrasonic waves during printing is significantly different: the alloy crystals are very small and completely isometric, which means that they are formed evenly in all directions of the printed metal components. “
In addition, by turning the ultrasonic generator on and off during the printing process, you can create individual projects with different microstructures in different areas. This is a quality known as “functional grading” and is useful in objects that consider factors such as low weight or reduced material use.
The researchers believe that once ultrasonic-enhanced 3D printing technology is further developed, it will also be difficult to use in other metals such as stainless steel, aluminum alloys and cobalt alloys.