EFFECT OF THE SCANNING SPEED OF TREATMENT ON THE MICROSTRUCTURE, MICROHARDNESS, WEAR, AND CORROSION BEHAVIOR OF LASER METAL-DEPOSITED Ti-6AL-4V/TiC COMPOSITE

We investigate the influence of scanning speed on the microstructure, microhardness, wear, and corrosion resistance behavior of a titanium-alloy composite (Ti-6Al-4V/TiC composite) produced by using the process of laser metal deposition. A Rofin Sinar Nd-YAG laser was used to produce the samples for a laser power of 2.5 kW, a powder flow rate of 2 g/min, and a gas flow rate of 2 liter/min. The scanning speed was varied between 0.005 and 0.050 m/sec. The microstructural studies were carried out using an optical microscope and a scanning electron microscope. The microhardness profiling was done using a Vickers microhardness tester under a load of 500 g for a dwell time of 15 sec. The dry sliding wear of the composite was investigated by using a ball-on-disk tribometer for a load range of 25 N. The corrosion behavior was evaluated in a 3.5% NaCl solution by the potentiodynamic polarization measurement method. We used both unmelted carbide particles and dendritic TiC. The percentage composition and distribution of all these particles were found to change depending on the scanning speed. The microhardness was found to increase as the scanning speed increased. The wear volume produced was found to decrease as the scanning speed increased. The electrochemical behavior of the composites shows that the corrosion potential and corrosion rate decrease as the scanning speed increases.