Department of Industrial Engineering

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Browsing Department of Industrial Engineering by Subject "3D printed cutting tools"

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    Laser powder bed fusion of cemented tungsten carbide cutting tools
    (Stellenbosch : Stellenbosch University, 2022-04) Hagedorn-Hansen, Devon; Sacks, Natasha; Damm, Oliver; Matope, Stephen; Stellenbosch University. Faculty of Engineering. Dept. of Industrial Engineering.
    ENGLISH ABSTRACT: Cemented carbides are extremely hard, wear resistant materials, and one of the most widely used tool materials in numerous manufacturing industries. Metal cutting tools are commonly manufactured from cemented carbides using standard powder metallurgy processes such as the press and sinter process. The tooling market is highly competitive and the companies with the best research and development departments have the competitive advantage when it comes to cutting edge technology. However, historically, the development process for a new cutting tool or production technology is a lengthy and costly venture. The use of laser powder bed fusion (L-PBF) for research, development, and small-batch production of cemented tungsten carbide cutting tools has not been extensively reported, and commercialisation does not seem apparent as yet. While the usage of L-PBF to produce cutting tools may be beneficial to advancing cutting tool technology, the process has many inherent drawbacks that affect part quality. However, there are many changes to the current L-PBF process that can be investigated to improve the final quality of L-PBF-produced tools before post-processing. The successful application of L PBF technology could help develop and manufacture cutting tools at an improved rate. The aim of this study was to determine and manage the influences of certain factors encountered during L-PBF of tungsten carbide cobalt (WC-Co) and their effects on specific cutting tool properties and cutting performance to produce L-PBF cutting tools that could be comparable to a conventionally produced tool. To accomplish this, three powders were analysed and investigated for their use in the L-PBF process. Then, characterisation of an existing cutting tool was performed to be used as a quality benchmark for L-PBF cutting tools. After a reasonable understanding of powders and conventional cutting tools was obtained, single track scans were performed on a tool steel base plate to understand adhesion and the feasibility of using a conventional base plate. The next stage of the study involved understanding the effects of different laser parameters and scanning strategies on the track morphology, density, hardness, and cobalt content of L-PBF produced WC-12wt%Co samples. Various parameter optimisation methods and strategies were tested and L-PBF-produced cutting tools were utilised in preliminary cutting tests to determine their cutting ability and to deduce which factors had the greatest effects on cutting contact time. The L-PBF scanning strategy was observed to be the most significant factor for successful cutting operations. A diagonal raster strategy with an 80-degree alternating rotation produced the best cutting inserts for the specific insert geometry and grade. Verification WC-12wt%Co inserts were produced with L-PBF for final cutting tests. These inserts were comparable to conventionally produced tungsten carbide inserts with respect to cutting performance indicators such as contact time and workpiece surface roughness. On average, after roughly 16M30S contact time, the L-PBF cutting tools exhibited 0.7 mm maximum flank wear versus 0.4 mm for similar conventional inserts. These results suggest that L-PBF could, one day, be a viable solution for research, developments, and small-batch production of WC-Co cutting tools.