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In the present study, the wear resistance behavior and the microhardness of the Co38Ni35Al27 and Co35Zn10Ni32Al23 ferromagnetic shape memory alloys (FSMAs) were investigated. The alloy samples were prepared by powder metallurgy method along with the vacuum sintering technique. The major aim is to prepare an alloy with high wear resistance having remarkable microhardness suitable for the sustainable shape memory alloy. The wear test report shows that the wear resistance is high for the sample sintered at 673 K and it gradually reduces when the sintering temperature decreases. The result also shows that the inclusion of zinc in the alloy increases the wear rate. The maximum hardness value of 126 HV was observed in Co38Ni35Al27 sample sintered at 673 K for 8 hrs because of its minimal porosity.

Co38Ni35Al27 and Co35Zn10Ni32Al23 ferromagnetic shape memory alloys were prepared via facile powder metallurgy and vacuum sintering technique. The influence of sintering temperature on phase transformation behaviour, microstructure and magnetic properties were investigated. The rise in peak intensity of A2-phase shows that the alloy is rich in martensitic-phase in the polycrystalline cubic B2-phase structure and Zn incorporation leads to the reduction in austenite-phase. The needle-shaped cobalt precipitates on predominant martensite A2-phase, shows Widmanstatten-like structure in the samples sintered at 673 K. The saturation magnetization was found to be 87.92 and 96.2 emu/g for Co38Ni35Al27 and Co35Zn10Ni32Al23 alloy. The existence of non-interacting single-domain particles were observed and proved using Stoner-Wohlfarth model.

Co-Ni-Al alloy samples were prepared by compacting the powdered alloy at various pressures in proper stoichiometric ratio and the high density compacted alloy was sintered at 673 K. The magnetic, mechanical properties, microstructure and phase analysis were studied and compared with that of spark plasma sintered (SPS) alloy. The sintered alloy exhibit martensitic twin variants with ? phase structure. Along with the diffused particle, few agglomerated clusters were observed on the topographic images. The magnetic and the mechanical studies of the test specimens were investigated using the vibrating sample magnetometer, pin on disk tribometer and universal testing machine respectively. The coercivity value and the ductility of the SPS alloy are higher than the same of the as-sintered alloy.

The CoNiAl alloys are prepared by using the spark plasma sintering (SPS) technique. The present study investigates the crystalline structure , Phase analyses, Physical and mechanical properties of the stoichiometric Co38Ni35Al27 alloys. The significant control over the magnetic and structural transformation temperature and high ductility of CoNiAl makes it a potential high-temperature Ferromagnetic shape memory alloy (FSMA). The test specimens were prepared at SPS temperature of 1000 °C at a sintering pressure of 50 MPa. The microstructural identification and the phase analyses of the mechanically alloyed powders and the SPS sintered specimens were investigated using optical microscopy, scanning electron microscopy and X-ray diffraction. The room temperature XRD results revealed that the sintered samples have body centred cubic β phase. A comparison of the room temperature XRD results for alloy powders and that of the sintered alloys has been studied. From the SEM images, we observe that the sintered alloys have martensitic twin variants. Also in the optical microscope, we observe the martensitic variants in the β phase structure. From the thermal studies, we analysed the phase transformation behaviour of the sample from β’ martensite to β martensite at 120°.