Ni-Mn-Al Heusler Alloy Samples Preparation by Mechanical Alloying Method and Study of their Investigated Properties

Abstract

Objective: In this work, ternary Ni-Mn-Al Heusler alloy powder samples were fabricated using mechanical alloying technique to study its alloy formation mechanism and the effects of mechanical alloying on the investigated properties. Methods: The samples were prepared using high energy planetary ball mill under argon conditions. The milling time of 0 h (hour/hours), 5 h, 10 h and 15 h were selected to see the progress of alloy formation. The microstructural, compositional, thermal and magnetic studies of ball milled powder samples were conducted. Findings: Compositional study reveals stoichiometric Heusler composition (X2YZ) of Ni-Mn-Al alloy with no contamination. The optimum milling time required for the formation of alloy by mechanical alloying resulted through the proper selection of milling parameters. The average crystallite size obtained reveals that nanocrystalline structure of Ni-Mn-Al alloy was achieved during the ball milling operation. The successive heating of powder particles in differential scanning calorimetry showed crystallization and alloy formation. Novelty/Applications: The magnetic study indicated soft ferromagnetic nature of the selected ball milled powder sample suggesting the alloy can be developed for possible ferromagnetic shape memory alloy applications. Keywords: Ni-Mn-Al; Heusler alloy; Mechanical alloying; Ball milling; Structural properties