Effects of Processing Parameters of Selective Laser Melting Process on Thermal Conductivity of AlSi10Mg Alloy

Selected laser melting (SLM) is a representative process of powder-bed type 3D printing technology that is used to manipulate metals and it generally results in various structural properties according to the process conditions. In this study, a thermal conductivity test was conducted on AlSi10Mg specimens that were manufactured using the SLM process to investigate the influence of various process conditions on the thermophysical characteristics and cellular microstructure of the samples. The building direction of the specimen, laser scan speed, and hatch spacing were considered as process variables, and the thermal conductivity was analyzed for each process variable. In the test results, as the polar angle of the specimen increased from 0° to 90°, the thermal conductivity increased. Furthermore, the thermal conductivity gradually decreased as the scan speed and hatch spacing increased. The differences in thermal characteristics are discussed in connection with the microstructure of the cells constituting the melt pool. The solidified melt pool that formed by the laser beam is composed of cells consisting of an Al matrix and a surrounding Si-rich area. The differences in thermal conductivity of the overall specimens are explained based on the variations in thermal conductivity and cell shape and size for each chemical component.