Defect detection in 3D printed carbon fibre composites using X-ray Computed Tomography

X-ray Computed Tomography (X-ray CT)has becomea vital tool for product quality inspection.TheX-ray CT analysis of 3D printed composites, with a layer-by-layer structure of carbon fibre/polyamide and polyamide plies, demonstrates how the void contentincreases with an increasing number of consecutive carbon fibrelayers.Not only the void content, but also the pore network complexity increases, as more pore types are introduced into the sample. The PolyAmide(PA)matrixhas an averagevoid content of 6%, consisting of interbead channelswith strong anisotropy. Alternating a carbon fibrelayer with two polyamide layers slightly increases porosity (6.8%on average), as both inter-and intrabundle porositiesare now present. It wasfound that thepremature cuttingof the carbon fibrebundle resultsin a large voidat the end of the print path, while the startof the pathis also associated with voids and an interruption of the PA wall layers.Full carbon fibrelayering sections introduce additional large voids (average porosity of 9.7%), as the carbon fibrebundle cannot fully move into the corners of the polyamide wall layers.The tested samples exhibit a delamination failure mode in the performed indentation test. The 100°PA2CFlay-up exhibits the best performance, yieldingthe highest loading and actuation potential. The presence of a PA layer between CF layers is beneficial for the mechanical performance of the printed carbon fibre composite. While reinforcements are introduced to enhance the mechanical strength and elasticity of thermoplastics, or to invoke an actuation mechanism,the final material properties strongly depend on the used fillpattern, the location of the start and end pointsofthe print pattern, the turn radius, the lay-up, and more specifically thenumber of consecutive reinforcement layers.

Jaar van publicatie:2019

Toegankelijkheid:Open