Martensitic Transformation in Spark Plasma Sintered Compacts of Ni-Mn-Ga Powders Prepared by Spark Erosion Method in Cryogenic Liquids
Ni-Mn-Ga-based magnetic shape memory materials were elaborated by spark plasma sintering method. Micron sized particles were prepared by spark-erosion method in liquid argon and liquid nitrogen from preliminary melted magnetic shape memory master alloys Ni-28.5Mn-22.5G at.%. Powders were annealed in H2 gas atmosphere before sintering. Depending on the cryogenic liquids the morphology of particles alternated between spherical solid and hollow balls. The conditions of spark eroded powder elaboration strongly effect on the morphology, martensitic behavior, and structure of sintered samples. In particularly, martensite has 5M structure in bulk material; 14M and non-modulated martensites were found in annealed powders and sintered compacts correspondingly.
Sergey Prokoshkin and Natalia Resnina
P. Ochin et al., "Martensitic Transformation in Spark Plasma Sintered Compacts of Ni-Mn-Ga Powders Prepared by Spark Erosion Method in Cryogenic Liquids", Materials Science Forum, Vols. 738-739, pp. 451-455, 2013