The Effect of Laser Based Synthesized Ti-Co Coating on Microstructure and Mechanical Properties of Ti6al4v Alloy

The distinctive properties of Ti-6Al-4V alloy coupled with its poor tribological properties make it a subject of numerous researches. While titanium alloys possesses vast applications and excellent properties, their low hardness and poor tribological behaviour have retarded their applications in engineering applications. In this work, the microstructures and micro - hardness values of Ti-Co intermetallics reinforced on Ti6Al4V, were investigated. Laser surface cladding technique was employed using Nd: YAG high power laser beam for the synthesis of the powders. The feedstock powders were premixed and deposited on Ti6Al4V with varying compositions at scan velocity of 1.2 m/min. Laser power of 900W and beam size of 3mm with argon shield gas flow rate of 1.2l/min were set as the operating laser parameters. Phase identification and morphological studies of the resultant coatings were carried out using scanning electron microscopy (SEM) equipped with energy dispersive spectrometry (EDS) respectively. The coatings displayed fine microstructure and good metallurgical bonding with the substrate containing minute or no defects such as cracks and pores. The results revealed the formation of fractions of Ti2Co and TiCo3 inter - metallic phases dispersed within the coating matrix which could be responsible for the enhanced properties attained. The hardness was increased by 150% as against the substrate.