An investigation of the effect of fiber surface treatment on the flexural properties of 3D printed composites

Mechanical performance of polymer parts produced by fused deposition modeling (FDM), especially for thermoplastic materials, is a major concern. The interface between fibers and matrix plays an essential role in the mechanical properties of the 3D printed composite parts. Weak adhesion can be due to the reluctance of two components to adhere to each other, which is caused by the absence of active functional groups on the fibre s surface. Carbon fiber is also one of those materials that has a very limited functional group on its surface. In this research, the effect of nitric acid oxidization treatment on the interface of carbon fiber-reinforced acrylonitrile butadiene styrene (ABS) composite is investigated. Three-point bending tests were carried out on 3D printed specimens. Experimental results show that the bending strength of composite samples reinforced with fibers without surface modification was equal to 135 MPa while these values have increased to 164 MPa for samples reinforced with surface modified fibers. The results indicate the improvement of adhesion between carbon fibers and ABS matrix.