【摘要】 聚醚醚酮(Polyetheretherketone,PEEK)具有极高的耐热性与优良的机械性能,适合用于航空高温环境。而利用增材制造(Additive manufacturing,AM)制备轻质点阵结构,可替代常规的实体结构,实现航空零部件的轻量化。为此,制备了PEEK/Ta/Nb复合粉末材料,通过高温激光选区烧结(High temperature–selective laser sintering,HT–SLS)增材制造技术成形PEEK/Ta/Nb三周期极小曲面Gyroid梯度点阵结构,研究了复合材料点阵结构的压缩性能并阐明了结构断裂机制。研究表明,Gyroid梯度点阵结构在单元连接处虽然可以平滑过渡,但应力最先在孔隙率较大的斜杆处产生集中,达到临界值时逐层坍塌,断裂方向呈45°角。PEEK/Ta、PEEK/Nb与PEEK/Ta/Nb的屈服强度较PEEK(1.19MPa)分别提升了23.5%、6.7%与44.5%。更多还原

【Abstract】 Polyetheretherketone(PEEK) has high heat resistance and excellent mechanical properties, suitable for the applications in high temperature environment of aviation. Light lattice structures can be produced by additive manufacturing(AM) to replace the conventional solid structure and realize the lightweight of aviation parts. Therefore, in this paper, the PEEK/Ta/Nb composite powders are prepared, and the triply periodic minimal surface(TPMS) gyroid lattice structures of PEEK/Ta/Nb were fabricated by high temperature–selective laser sintering(HT–SLS) additive manufacturing technique. The compressive properties of composite lattice structures were studied and the fracture mechanism was clarified. The results show that gradient gyroid lattice structure allows smooth transition at the cell junctions, but the stress concentrates at the inclined bar of large porosity, which can lead to a layerwise collapses at a 45° fracture direction. The yield strength of PEEK/Ta, PEEK/Nb and PEEK/Ta/Nb is increased by 23.5%, 6.7% and 44.5% respectively compared with that of PEEK(1.19 MPa).更多还原