Effect of post-treatment on local mechanical properties of additively manufactured impellers made of maraging steel

Abstract

Purpose This study aims to investigate the effect of the wall thickness, deposition orientation and two different post-processing methods on the local mechanical properties and microstructure of additively manufactured parts made of maraging steel. In order to examine the local properties of the build, miniaturized testing specimens were employed. Before application of small-sized specimens, their performance was verified. Design/methodology/approach The investigation was composed of two stages. As first, the part thickness, specimen size and orientation were studied on a laser-powder bed fusion (L-PBF) platform with deposited walls of various thicknesses made of maraging steel. Subsequently, the influence of different heat-treatment methods was investigated on the final product, i.e. impellers. The miniaturized and standard tensile tests were performed to investigate the local mechanical properties. The porosity, microstructures and fracture surfaces were analysed by X-ray-computed tomography, X-ray diffraction and scanning electron microscopy with electron backscatter diffraction. Findings The results revealed good agreement between the values provided by miniaturized and standard specimens. The thinnest parts produced had the largest pores and the highest scatter of elongation values. In these cases, also the sub-contour porosity was observed. Part thickness affected pores’ size and results repeatability but not total porosity. The two-step heat-treatment (solutionizing and age-hardening) exhibited the highest yield and ultimate tensile strength. Practical implications The microstructure and local mechanical properties were studied on L-PBF platform with deposited walls of various thicknesses. Subsequently, a detailed analysis was conducted on real components (impellers) made of maraging steel, commonly used in tooling, automotive and aerospace industries. Originality/value The broadly understood quality of manufactured parts is crucial for their reliable and long-lasting operation. The findings presented in the manuscript allow the readers better understanding of the connection between deposition parameters, post-processing, microstructure and mechanical performance of additive manufacturing-processed parts.

Using adaptive slicing method and variable binder amount algorithm in binder jetting

“…Impeller models have been widely used in the literature to measure the performance of 3D printers. There are many studies using impeller models (Peng et al , 2022; Mao et al , 2021; Hernández and Fragoso, 2022; Jayawardane et al , 2022; Raghavan et al , 2022; Kapil et al , 2018). Therefore, the impeller model was chosen to see the effects of adaptive slicing.…”

Effect of Heat Treatment on the Resulting Dimensional Characteristics of the C45 Carbon Steel after Turning

“…The application of heat treatment is important in various areas of metal production, including additive manufacturing of semi-finished products, which are subsequently ma-chined to final dimensions [35,36]. Additive manufacturing can be regarded as a disruptive process that builds complex components layer by layer [37].…”