Selective laser sintering of polyamide 12/potassium titanium whisker composites

摘要

The excellent performance of potassium titanium whiskers (PTWs) reinforced plastics has been recognized; however, because of their large length-to-diameter ratio, they have not been applied in selective laser sintering (SLS). This article reports a new method for preparing polyamide 12 (PA12)/PTWs composite (PPC) powders for applications in SLS that uses a dissolution-precipitation process. The characteristics of the powders were evaluated. The results indicated that when the PTWs content of the composites was low (>10 wt %), the shape of the powder became more regular, and the particle diameter distribution became narrower. The crystallinity of PPC was 13 wt % higher than that of PA12. The sintering characteristics and mechanical properties of PA12 powder, glass-filled PA12 (GF-PA), and PPCs were compared. The results showed that the sintering characteristics of PPCs (10 or 20 wt % PTWs) were as good as those of PA12. The mechanical properties were greatly improved by PTWs. The maximum tensile strength, bending strength, and bending modulus of the composites containing 20 wt % PTW were 68.3 MPa, 110.9 MPa, and 2.83 GPa, respectively, and were much higher than those of PA12 and GF-PA.