Effect of Fibre Laser Surface Treatment on Wear Resistance of Gray Cast Iron Astm A48

This work aimed to study the effect of pulse fibre laser surface treatment to modify the microstructure and wear characteristics of gray cast iron ASTM A48 class 30, which is the most widely used in automotive manufacturing parts. Pulse fibre laser treatment is advanced processes that have short pulses and high pulse repetition rates and this can be achieved without compromising average power to any great extent. Pulse fibre laser energy are 3.2kW, 4 kW, and 5 kW, pulse repetition is 0.75 ns, 1 ns, and 1.5 ns, spot diameter is 0.81mm, 0.72mm and 0.63 mm and with fix wavelength of 1064 nm. The gray cast iron type A48 was investigated, while Fibre laser was applied to modify the microstructure, wear resistance and micro- hardness. Laser surface hardening process was involved in heating and rapid cooling stages in the air medium. Scanning electron microscope (SEM) and optical microscopy (OM) has been used to study the microstructure cross-sectional of spot molted and heat- affected zones. X-ray diffraction (XRD) technique has been used to estimate the metallurgical phases. The results were noted that increasing laser energy and pulsed duration led to an increase in the area and depth of laser melted zone (LMZ). Also, it’s found increased in values of wear resistance and micro hardness after laser treated.