Nano-TiC-reinforced 18Ni300 steel manufactured by Powder Bed Fusion-Laser Beam with improved wear resistance for mould inserts

Abstract

In injection moulding, surfaces can be exposed to harsh working conditions, especially when polymers reinforced with abrasive glass fibres are used. Low carbon martensitic steels, such as maraging steels, are an excellent choice for demanding and complex mould inserts produced by Powder Bed Fusion-Laser Beam (PBF-LB). However, their wear resistance is lower than that of tool steels such as AISI D2 or H13, whose PBF-LB printability is challenging, due to their carbon content that makes them susceptible to cracking. In this study, an alternative material with high printability by PBF-LB was developed, by reinforcing maraging steel 18Ni300 with nano-sized titanium carbide (TiC). TiC-reinforced 18Ni300 nanocomposites showed an improvement in microhardness of up to 23% (730 HV2) after addition of 7.0 vol% TiC. Tribological tests against a polypropylene with 40 wt% glass fibres showed that the specific wear rate decreased by about an order of magnitude (to 0.32 × 10–6 mm3/N m) compared to the unreinforced maraging steel.