Aluminium alloy specimens were irradiated in vacuum (10-6 torr) with Nd-YAG laser for
different number of shots ranging from 100 to 500 with incremental steps of 100 shots. The
optical, structural and tensile properties of the specimens were studied using optical
microscope, X-ray diffractometer (XRD) and tensile testing machine. Laser ablation of the
specimen resulted in boiling, splashing and crater formation on its surface. The size of crater
initially increases and then gradually decreases with increase in number of laser shots. The
depth of irradiated area is found to be increases by increasing the number of laser shots. The
comparison of XRD analysis shows that an anomalous trend in the peak intensity, crystallite
size and dislocation line density of the specimen irradiated with different number of shots.
Mechanical properties of both irradiated and unirradiated specimens were investigated using
tensile testing machine. The changes in fracture strength and ultimate tensile strength were
found to be inconsistent with increasing the number of laser shots.
Keywords: Aluminium alloy, Nd-YAG laser, X-ray Diffraction, Optical microscopy.