INFLUENCES OF LASER INCIDENCE ANGLE AND WALL THICKNESS ON ADDITIVE COMPONENTS

Additive manufacturing (AM), particularly laser powder bed fusion, is growing the ability to rapidly develop advanced cooling schemes for turbomachinery applications. However, to fully utilize the design and development opportunities offered through AM, impacts of the build considerations and processing parameters are needed. Prior literature has shown that specific build considerations such as laser incidence angle and wall thickness influence the surface roughness of additively made components. The objective of this technical brief is to highlight the effects of both laser incidence angle and wall thickness on the surface roughness and cooling performance in micro-sized cooling passages. Results indicate that for any given laser incidence angle, surface roughness begins to increase when wall thickness is less than 1 mm for the cooling channels evaluated. As the laser incidence angle becomes further away from 90° the surface roughness increases in a parabolic form. Laser incidence angle and wall thickness significantly impacts friction factor, while there is less of an influence on Nusselt number for additively manufactured microchannels.