In situ design of advanced titanium alloy with concentration modulations by additive manufacturing

Additive manufacturing is a revolutionary technology that offers a different pathway for material processing and design. However, innovations in either new materials or new processing technologies can seldom be successful without a synergistic combination. We demonstrate an in situ design approach to make alloys spatially modulated in concentration by using laser-powder bed fusion. We show that the partial homogenization of two dissimilar alloy melts-Ti-6Al-4V and a small amount of 316L stainless steel-allows us to produce micrometer-scale concentration modulations of the elements that are contained in 316L in the Ti-6Al-4V matrix. The corresponding phase stability modulation creates a fine scale-modulated b + a' dual-phasemicrostructure that exhibits a progressive transformation-induced plasticity effect, which leads to a high tensile strength of similar to 1.3 gigapascals with a uniform elongation of similar to 9% and an excellent work-hardening capacity of >300 megapascals. This approach creates a pathway for concentration-modulated heterogeneous alloy design for structural and functional applications.

Automated summary

By utilizing laser-powder bed fusion, an in situ design approach has been demonstrated to achieve spatial modulations of concentration in alloys. This technique allows for the production of micrometer-scale concentration modulations in the matrix of Ti-6Al-4V, leading to a b + a' dual-phase microstructure with high tensile strength, uniform elongation, and excellent work-hardening capacity.