Effect of homogenization time on shape memory behaviour of NiMn alloy

Ni-Mn-Sb and Ni-Mn-Sb-Co shape memory alloys, which have attracted great attention in the literature in recent years, can be given shape memory properties by heat treatment. In this study; the determination of the effects of homogenization on magnetic shape memory alloys of polycrystalline Ni50Mn29Sb21-xCox'in (x = 0 or 8.5) and the effect of a Co doping on microstructure, magnetic and hardness properties was focused. Microstructure investigations carried out during the study show that Ni50Mn29Sb21 an Co doped Ni50Mn29Sb12.5Co8.5 alloy, which has undergone homogenization as revealed by X-ray diffraction experiments, are materials with different phases (γ (A1), B2 or L21) at high temperature. The data obtained on L10, and different layered martensites are discussed with different approaches. The metallographic observations carried out reveal the dendritic phase structure, which is an important distinction between different regions in terms of additive elements. By means of DSC and Thermomagnetic measurements, information about the transition temperatures of the studied alloys was obtained. Examination of mechanical properties based on Vickers microhardness measurements shows that Co addition has beneficial effect on material hardness.