Srinivasan Raghavan, Jan Dzugan, Sylwia Rzepa, Pavel Podany, Norman Soh, Lim Jia Hao and Niaz Khan
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…
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.
Details
Keywords
The traditional liberal-arts curriculum of the word-based Trivium (grammar, dialectic/logic, rhetoric) and the number-based Quadrivium (arithmetic, geometry, astronomy, music) has…
Abstract
Purpose
The traditional liberal-arts curriculum of the word-based Trivium (grammar, dialectic/logic, rhetoric) and the number-based Quadrivium (arithmetic, geometry, astronomy, music) has an intrinsic unity. Used in an integrated way, it provides a tool for self-development, self-realisation and self-integration. The purpose of this paper is to outline the core nature of the integrative quality of the liberal-arts curriculum, trace the gradual disintegration of the curriculum from its adoption in classical Greece, and provide practical suggestions for the re-integration of the curriculum in the context of modern educational practice.
Design/methodology/approach
The paper presents a philosophical survey of the history of the theory and practice relating to the intrinsic integrated quality of liberal-arts education from pre-classical Greece to the present day.
Findings
The integrated quality of the liberal-arts curriculum has experienced a gradual disintegration from its adoption in classical Greece to the twenty-first century. The paper provides practical suggestions for the re-integration of an integrated approach to the curriculum in the context of modern educational practice.
Practical implications
Re-engaging with the integrated quality of the liberal-arts curriculum is vital for fulfilling the purpose of education as a practice: that of enabling a human being to flourish in a holistic way, in order to take an active role within a civil society.
Originality/value
The paper provides a valuable antidote to overly rational thinking by arguing for the need to restore the intrinsic integrative quality of the liberal-arts curriculum in educational practice in order to support the flourishing of individuals, society in order for the emergence of a mutually supportive interaction between them to appear.