Sintering regimes and resulting microstructure and properties of binder jet 3D printed Ni-Mn-Ga magnetic shape memory alloys

Effect of process parameters on non-modulated Ni-Mn-Ga alloy manufactured using powder bed fusion

“…It is likely that this could be diminished by using a heated powder bed as it is known to reduce the formation of stresses and increase density of PBF parts [54]. A similar effect has been seen in the previously produced AM parts in the as-printed structures [30] with the main difference being that in samples manufactured using the binder-jet method [28,31,33] the homogenization and ordering can occur during the sintering treatment of the sample. However, as no binders containing carbon and oxygen [27] are needed in PBF, the risk of contamination during the heat-treatment process is lower.…”

“…As AM manufacturing methods have become more familiar, several attempts to use AM to manufacture Ni-Mn-Ga structures [27][28][29][30][31][32][33] and in other magnetocaloric materials [34] have been made. Additionally, the interaction of laser beam and Ni-Mn-Ga has been studied [35,36].…”

“…Additionally, the interaction of laser beam and Ni-Mn-Ga has been studied [35,36]. The AM methods that have so far been utilized with MSM have been binder jet printing [27,28,31], direct metal deposition [30,32] or a combination of both methods in the use of elemental inks [29]. So far it has been proved that complex shapes can be produced [29,31,33] using additive manufacturing methods.…”

“…So far it has been proved that complex shapes can be produced [29,31,33] using additive manufacturing methods. However, twins spanning grain boundaries have been observed only in a few studies [28][29][30][31]33], and only one study has so far reported MFIS [33] and the reported strain was lower than in polycrystalline Ni-Mn-Ga structures [7]. Additionally, in the case of additive manufacturing processes that utilize binders, extra care must be taken during binder removal so that no residual carbonaceous material is present after final sintering [29].…”

Additive Manufacturing of Ni-Mn-Cu-Ga: Influence of Sintering Temperature on Magnetocaloric Effect and Microstructure

“…In BJP, binder is selectively deposited layer-by-layer onto a powder bed to bind powder particles together, with subsequent curing and sintering for binder burn-out and densification. This process has been found viable for similar composition Ni-Mn-Ga [5].…”