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A 3D Printable High Entropy Alloy with High Strength and Ductility for Marine Applications
This technology offer contains a novel approach to drastically improve the 3D printability of CoCrFeNi high entropy alloy (HEA). It is achieved via material design by adding Al to the CoCrFeNi HEA, which can prevent the hot cracking of this material during 3D printing. This new method will attract the users who are keen to 3D print CoCrFeNi-based HEA for critical load-bearing marine & submarine parts used under harsh environments.
Technology Features, Specifications and Advantages
The CoCrFeNi high entropy alloy (HEA) has exceptional strength, high ductility and excellent corrosion resistance. However, it suffers poor printability when using 3D printing due to hot cracking, resulting in severe defects and inferior mechanical properties as compared to its conventionally manufactured counterparts. Many researchers have attempted to solve this problem by process parameter optimization but without success. In our proposed grain boundary segregation engineering approach, the printability problem can be resolved by simply adding 0.5 mole Al to this alloy to modify its chemical composition to Al0.5CoCrFeNi. By doing so, crack-free and fully dense parts can be successfully fabricated by 3D printing. The 3D printed Al0.5CoCrFeNi HEA material is 2 times stronger and 4 times more ductile than the original composition.
The primary application area is 3D printing industry who is interested in developing CoCrFeNi-based high entropy alloy (HEA). This technology can also be applied to marine & offshore industry, or other areas that require load-bearing parts to be used in corrosive environment. The potential products include pump housing, water turbine, propellers, jigs, fixtures, valves, etc.
This technology enables the previously non-3D-printable CoCrFeNi-based high entropy alloy (HEA) to be successfully printed with excellent mechanical properties and corrosion resistance for marine & offshore applications. It opens up new opportunities for material selection for 3D printing. It will accelerate a wider adoption of 3D printing in more industries that are interested in using high entropy alloy.
Further Technical Information
Our relevant work has been published in two high impact factor international journals: Z. Sun, X. Tan, M. Descoins, D. Mangelinck, S. Tor, and C. Lim, "Revealing hot tearing mechanism for an additively manufactured high-entropy alloy via selective laser melting," Scripta Materialia, vol. 168, pp. 129-133, 2019. Z. Sun et al., "Reducing hot tearing by grain boundary segregation engineering in additive manufacturing: example of an AlxCoCrFeNi high-entropy alloy," Acta Materialia, vol. 204, p. 116505, 2021.