选择性激光烧结铝/尼龙复合粉末材料

Selective laser sintering of aluminum/nylon 12 composite powder

制备了不同铝粉含量的尼龙12覆膜复合粉末,利用扫描电镜(SEM),能谱分析(EDX),差示扫描量热分析(DSC),热失重分析(TG)对粉末材料的形貌以及热性能进行了表征。对复合粉末进行激光烧结成形,并研究了不同铝粉含量对烧结件尺寸精度以及力学性能的影响。结果表明:尼龙与铝粉表面粘结良好,烧结过程中尼龙熔融,铝粉均匀分布在尼龙基体中;随着铝粉含量的增多,烧结件的弯曲强度和模量显著提高,冲击强度逐渐降低;铝粉质量分数为50 wt%时,烧结试样的弯曲强度和模量与纯尼龙烧结试样相比分别提高了62.1%和122.3%;铝粉含量的增多能够有效抑制尼龙基体的收缩,提高烧结件的精度。

Nylon 12-coated aluminum composite powders with different aluminum contents were prepared. The morphology and the thermal properties of the composite powder were characterized by SEM, EDX, DSC and TG. Specimens were fabricated by selective laser sintering （SLS）, then the effects of the aluminum content on dimensional accuracy and mechanical properties of the sintered part were studied. The results show that there is strong interfacial adhesion between nylon and aluminum powder, the nylon is melted during the sintering process and aluminum powders are dispersed uniformly in the nylon matrix. As the aluminum content increases, the flexural strength and modulus of the sintered part increase remarkably, but the impact strength decreases gradually. With 50 wt% aluminum content, the flexural strength and modulus of the sintered part are improved by 62.1 % and 122.3%, respectively, compared to the sintered part of nylon powder. The increasing of aluminum content would effectively restrain the shrinkage of the nylon matrix, and enhance the dimensional accuracy of the sintered part.