This work provides an in-depth investigation of the influence of laser energy density on the mechanical, surface, and dimensional properties of carbon fiber-reinforced PA12 parts manufactured by selective laser sintering (SLS). A space-filling design of experiments (DOE) was used to conduct the experimental trials to cover a wide range of laser sintering parameters. The consolidation mechanism was evaluated by microstructural and crystallization evolution of the samples produced at different energy densities, supported by mechanical testing, scanning electron microscopy (SEM), X-ray diffraction (XRD), and infrared spectroscopy (FTIR). Surface morphology was evaluated by profile measurements and SEM images. Laser sintering parameters had a significant influence on physical and mechanical properties, exhibiting complex and nonlinear behavior. Low energy density resulted in better dimensional accuracy, whereas intermediate laser energy resulted in the best mechanical properties. A trade-off could be seen when mechanical or dimensional properties were desired, and optimum energy values were strongly dependent on the criteria desired. All samples exhibited a brittle fracture behavior, with little plastic deformation present. Fracture mechanism occurred in the interlayer region or interface between carbon fiber and PA12, depending on the energy density applied. XRD analysis revealed a decrease in crystal fraction with increasing energy density. FTIR measurement suggested that polymer degradation at high energy densities could be present by both polymer chain scission and oxygen functional group decomposition and gas release upon laser heating of carbon fiber, resulting in lower mechanical properties.

这项工作深入研究了激光能量密度对通过选择性激光烧结（SLS）制造的碳纤维增强PA12零件的机械，表面和尺寸特性的影响。实验的空间填充设计（DOE）用于进行实验试验，以涵盖各种激光烧结参数。通过机械测试，扫描电子显微镜（SEM），X射线衍射（XRD）和红外光谱（FTIR）的支持，通过在不同能量密度下生产的样品的微观结构和结晶演变来评估固结机理。通过轮廓测量和SEM图像评估表面形态。激光烧结参数对物理和机械性能有重大影响，表现出复杂和非线性的行为。低能量密度导致更好的尺寸精度，而中等激光能量导致最佳的机械性能。当需要机械或尺寸特性时，可以看到一个权衡，并且最佳能量值强烈取决于所需的标准。所有样品均表现出脆性断裂行为，几乎没有塑性变形。断裂机理发生在碳纤维和PA12之间的夹层区域或界面，具体取决于所施加的能量密度。XRD分析表明，随着能量密度的增加，晶体分数降低。FTIR测量表明，高能密度下的聚合物降解可能会由于聚合物链断裂和氧官能团的分解以及碳纤维激光加热时释放的气体而出现，