Evaluation of carbon fibre powder scrapers used in metal additive manufacturing

Abstract

Powder Bed Fusion (PBF) is an Additive Manufacturing process which builds parts, layer by layer, by melting the cross-section of the part onto a powder layer. Aeroswift is a PBF machine, designed and built in South Africa. A carbon fibre brush powder scraper was designed for Aeroswift, which would be flexible, work for extended periods of time and have the ability to operate at high temperatures. Uncertainty regarding the quality of the powder layer produced by this scraper called for the need of an evaluation method. Different methods of evaluating the quality of a powder layer were investigated. A Laser Line Scanner proved to be the best option due to its accuracy and quantitative evaluation abilities. Different powder scrapers we used to scrape layers, which was measured with a Laser Line Scanner. Results showed this method could indeed be used for a quantitative evaluation of a powder scraper and as a result be used to compare and qualify a powder scraper. A conclusion was drawn that the Aeroswift designed powder scraper performs comparably to a commercial carbon fibre brush scraper and produces a satisfactory powder layer.