4D printing of Ni–Mn–Ga magnetic shape memory alloys: a review

4D printing has grown tremendously in the last decade, enabling functional structures made of smart materials to be manufactured. Current metal research focused on thermal shape memory alloys (SMAs) and a lesser extent magnetic SMAs. This review assesses progress Ni–Mn–Ga, highlighting key challenges opportunities for applications. The mechanism SMAs influence process parameters microstructure material properties are explored, with an emphasis laser powder bed fusion processing. Control porosity, microstructure, texture impact post-processing performance development Ni–Mn–Ga printing.