A team of researchers led by the City University of Hong Kong has used additive manufacturing to design a new titanium-based alloy: one that’s ‘super-strong, highly ductile, and super-light.
When we think of 3D printing, we tend to think of its ability to produce complex geometries, but the Hong Kong team has turned this on its head, repurposing the technology for materials development applications instead.
Dr Zhang Tianlong, the first author of the study, maintains that we should begin considering additive as a multi-functional tool: “We unveiled that it has important potential in designing materials, rather than simply designing geometries.”
The scientists believe their work could pave the way for a new materials development paradigm, whereby 3D printing technology is used to create alloys with structures and properties suitable for industrial applications.
A lack of uniformity in metal alloy parts is usually an undesirable characteristic, as it can lead to properties such as brittleness. This is still one of the issues it is trying to overcome in additive manufacturing, as high-temperature processes like powder bed fusion often result in rapid part cooling, which itself can lead to inhomogeneity in metal 3D printed components.
However, according to Dr Zhang’s previous modeling and simulation studies, a certain degree of inhomogeneity may be beneficial to an alloy part’s properties, as it can produce unique and heterogeneous microstructures. As such, the present study leverages what most consider to be a shortcoming of 3D printing – when life gives you lemons, right?
The Hong Kong team’s method involves melting two dissimilar alloys together using the focused laser beam of a powder bed fusion 3D printer. In this case, Ti64 was melted and mixed with 316L stainless steel. By carefully controlling certain printing parameters such as laser power and scanning speed, the scientists found that they could create a non-uniform composition in a controllable manner – a new alloy.