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The study of laser cladding of 90Ti-10Al 2 O 3 , 90Ti-8Al 2 O 3 -2Zn and 90Ti-4Al 2 O 3 -6Zn coatings onto Ti-6Al-4V alloy, with intention to produce defect-less, high microhardness and wear resistant coating was carried out. The coatings were deposited onto Ti-6Al-4V alloy at 900 W laser power and 0.6 m/min laser scan speed. Microstructures and phase constituents of the developed coatings were investigated by using a scanning electron microscope (SEM) and Xray diffractometer correspondingly. Vickers microhardness tester and pin-on-disk tribometer were employed to characterize microhardness and wear behaviour of the Ti-Al 2 O 3 /Zn coatings respectively. SEM was also used to examine the worn track. It was observed that 90Ti-10Al 2 O 3 coating yielded optimal microhardness along with maximal wear resistance in comparison to the other coatings and Ti-6Al-4V alloy. It has been established that laser cladding of Ti-Al 2 O 3 coating with Zn contents on Ti-6Al-4V alloy alleviates the formation of cracks, however, microhardness and wear properties are negatively affected.

The need for new advanced high temperature materials is in high demand. High Entropy Alloy (HEAs) has been described to possess excellent mechanical oxidation and good corrosion resistance properties even far above the ambient temperature. Attempts are made in this research to study the corrosion, oxidation, microhardness and densification properties of Al15Ti30Si30Mo15Ni10 HEA produced by spark plasma sintering (SPS) for high temperature applications. In addition, the effects of SPS temperature (800, 900 and 1000°C) on the microstructure and phase formation of the developed HEA were reported. The microstructural modification and phases present were examined using the scanning electron microscope (SEM) equipped with the energy dispersive spectroscopy (EDS) and X-ray diffractometer (XRD) respectively. Ordered FCC and BCC systems were identified along with clearly defined crystal lattice along with Mo, Ti and Si rich regions were observed. No pores or cracks were observed from the microstructures. Densification of 98.8% accompanied with microhardness of 1445.29HV was achieved for both HEA at 1000°C. The Al15Ti30Si30Mo15Ni10 HEA fabricated at 1000°C displayed a higher polarization value of 3477 Ω.