Characterization of mechanical properties and fracture mode of PLA and copper/PLA composite part manufactured by fused deposition modeling

In this paper, fused deposition modeling is used to process pure polylactic acid (PLA) and copper fiber reinforced PLA composite (Cu/PLA) specimen. Comparative experiments are performed on printed specimens of different raster angles (0 degrees, 90 degrees, 45 degrees, 0 degrees/90 degrees and +/- 45 degrees, respectively). Tensile testing, dynamic mechanical analysis (DMA), and fracture surface analysis are employed to characterize all the specimens. The DMA exhibits remarkable improvement on storage modulus and loss tangent of Cu/PLA composite specimen. Due to the lower tensile strength and higher elasticity of Cu fiber compared with PLA, the tensile strength of Cu/PLA composite specimen decreases with the addition of Cu fiber, while the elongation-at-break increases. Both PLA and Cu/PLA specimens printed at a raster angle of 0 degrees show highest tensile strength and dynamic mechanical properties, while the 90 degrees raster angle with the lowest value. Fracture morphologies indicate that the failure of a specimen of 0 degrees raster angle is intra-layer fracture, while inter-layer fracture occur in the specimen of 90 degrees raster angle.