Selective laser melting of Inconel 601 alloy using nanosecond fibre laser

Abstract

The paper describes the impact of selective laser melting factors including using a nanosecond fibre laser, including laser powers, scanning speed, and thickness of layer, on the relative density and micro hardness Vickers of IN 601 samples was studied. Selective laser melting (SLM) is a commonly used powder bed fusion metal additive manufacturing (AM). Recent advances in additive manufacturing have attracted significant industrial interest, especially for producing metallic parts. Scanning electron microscopy (SEM), EDX and other techniques were utilized for studying the effect of speed of scanning and power of laser on densification behaviour, microstructural evolution and micro hardness of Inconel v alloy that was processed by SLM. With a VED of 3200 J/mm3, a scan speed of 250 mm/s with a 80 W, micro cracks of about 79-93 µm and voids of about (4.5 µm – 5.7) µm in diameter were realised. Moreover, the best hardness of 394 HV was attained with 80 W laser power. However, increasing the energy to more than the required values increased the porosity and decreased hardness. Using microsecond laser in SLM leads to the achievement of full density (almost 99.5%), whereas using nanosecond laser allows the achievement of less density (75-95%), which will be very useful for functions that require a porous structure and less weight, such as those in the aerospace applications, automotive industry and so on.