用于选择性激光烧结成型的聚酰胺6/硫酸钙复合粉体的制备及性能研究

Preparation and Performance Investigation of PA6/CaSO Composite Powders for Selective Laser Sintering Molding

采用溶液沉淀法制备了聚酰胺6/硫酸钙(PA6/Ca SO_(4))复合粉体,通过扫描电子显微镜(SEM)、差示扫描量热仪(DSC)、激光粒度分布仪和X射线衍射仪(XRD)对复合粉体的微观形貌、热性能、粒度分布、晶体结构和流动性进行了表征。结果表明,随着Ca SO_(4)的加入,PA6/Ca SO_(4)复合粉体由松散的球形结构转变为密实的球形结构;Ca SO_(4)的加入能够提高PA6/Ca SO_(4)复合粉体的结晶度并拓宽其烧结温度窗口,在Ca SO_(4)含量为5%(质量分数,下同)时,结晶度和烧结温度窗口均达到最大值,分别为61.84%和18.95℃;PA6/Ca SO_(4)复合粉体的粒径随Ca SO_(4)含量的增加呈现先减后增的趋势,休止角先减后增,堆积密度先增后减;当Ca SO_(4)含量为3%~5%时,PA6/Ca SO_(4)复合粉体的流动性能最佳,最适用于选择性激光烧结。

In this study,PA6/Ca SO_(4)composite powders were prepared using a solvent precipitation method.Their microstructure,thermal properties,particle size distribution,crystal structure,and flowability were investigated by SEM,DSC,XRD and laser particle size-distribution analysis.The results indicated that the PA6/Ca SO_(4)composite powders transformed from a loose spherical structure to the dense spherical one with the addition of Ca SO_(4).The introduction of Ca SO_(4)increased the degree of crystallinity(Xc)of the composite powders and broadened their sintering temperature window.When the Ca SO_(4)content was 5 wt%,the Xcreached maximum value of 61.84%and the sintering temperature window reached a maximum value of 18.95℃.Moreover,the particle size and repose angle of the composite powders decreased at first and then tended to increase with an increase in the Ca SO_(4)content.However,their bulk density showed an increasing trend at first and then tended to decrease.The composite powders exhibited optimal flow performance at the Ca SO_(4)content ranging from 3 to 5 wt%,which was most suitable for selective laser sintering.