Study of Properties of 3D Printed Short Carbon Fiber Composite

The properties of composite materials do not depend only on the properties of raw materials but also other parameters such as volume fraction, geometry, dimension and material distribution etc. Carbon fiber reinforced polymer is one of the top choices of composite material because carbon fiber has light weigh with high tensile strength. For fiber-based composite such as carbon fiber composite, directions of carbon fiber with respect to loading direction could also affect to the strength of composite material under load. In this work, the properties of short carbon fiber-resin composite were investigated (fiber length of 0.2 mm.) with two different fiber orientations, i.e. 0 and 90 degrees to applied load. The 3D printing technique was employed in order to control carbon fiber direction and minimize material loss leading to material cost reduction. It was found that 3D printing technique could control direction of fiber in most case. However, at area with high curvature, the unexpected fiber direction was observed due to post hot process during which material flow was expected. It should also be noted that fiber path during 3D printing process may be very crucial as it could result in low strength local area due to low fiber density. This area could promote stress concentration leading to final fracture.