Morphology and Properties of Selective Laser Sintered Bisphenol A Polycarbonate

Selective laser sintering (SLS) was used to process bisphenol A polycarbonate (PC) powder. The effects of the energy density of the laser beam (ranging from 0.036 to 0.12 J/mm²) on the morphology and physical and tensile properties of the sintered specimens were investigated. In general, high energy density of the laser beam resulted in better fusion of the PC particles and enabled a more compact structure to be built. When the energy density became excessively high, however, severe degradation of the polymer occurred, leading to the evolution of gases and a reduction in the molecular weight. Consequently, the physical density and tensile strength of the sintered specimens decreased, and the surface roughened. The tensile strength of the specimens was closely related to the physical density, and anisotropy was observed along different loading directions. Bonus Z increased rapidly during sintering of the first few layers and then gradually during sintering of the subsequent layers. Curling of the sintered specimens became severe at high energy density, and cracking was observed on the bases of multilayered specimens as a result of the excessive accumulation of residual tensile stresses. this work forms a basis for the production of selective laser sintered PC functional parts.