Abstract
Laser additive manufacturing is a direct energy deposition process which manufactures components from 3D model data in progressive layers until a whole part is built as opposed subtractive manufacturing. However, during the procedure, the deposits are subjected to rapid thermal stresses which adversely impact the integrity of the built component. High entropy alloys are materials with complex compositions of multiple elements. Traditionally, these alloys are fabricated using casting and other machining processes, with a recent interest in the use of laser deposition as a possible manufacturing process. To optimize process parameters of high entropy alloys melted on a steel plate, the influence of preheating temperature on the overall quality, microstructure and hardness behaviour of the alloys for aerospace applications were investigated. In this research, 9 samples of AlCoCrFeNiCu and AlTiCrFeCoNi high entropy alloys were fabricated using different laser parameters. The phases, chemical composition , micro-hardness and structural morphologies were characterized with XRD , EDS , Vickers Microhardness tester and SEM respectively before and after preheating the base plates at 400 °C. Experimental results show extensive cracking on all the samples without preheating while after preheating all samples were observed to be crack-free. Although, there were no variations on the dendritic structures in the optical micrographs with and without preheating temperature, there were notable changes in the phases and hardness behaviour of the alloys showing that preheating the base plate from 400 °C significantly influences the mechanical properties of additive manufactured high entropy alloys and contributes to the elimination of cracks induced by thermal stresses .
Access this chapter
Tax calculation will be finalised at checkout
Purchases are for personal use only
References
Owen DG (2001) Manufacturing Defects. SCL Rev 53:851
Oberländer B, Lugscheider E (1992) Comparison of properties of coatings produced by laser cladding and conventional methods. Mater Sci Technol 8(8):657–665
Lepski D, Brückner F (2009) Laser cladding. In: The theory of laser materials processing. Springer, Berlin, pp 235–279
Brückner F, Lepski D (2017) Laser cladding. In: The theory of laser materials processing. Springer, Berlin, pp 263–306
Nazemi N, Urbanic J, Alam M (2017) Hardness and residual stress modeling of powder injection laser cladding of P420 coating on AISI 1018 substrate. Int J Adv Manuf Technol 93(9–12):3485–3503
Brückner F, Lepski D, Beyer E (2007) Modeling the influence of process parameters and additional heat sources on residual stresses in laser cladding. J Therm Spray Technol 16(3):355–373
Eslami MR et al (2013) Theory of elasticity and thermal stresses, vol 197. Springer, Berlin
Clyne T, Gill S (1996) Residual stresses in thermal spray coatings and their effect on interfacial adhesion: a review of recent work. J Therm Spray Technol 5(4):401
Zumofen L et al (2017) Quality related effects of the preheating temperature on laser melted high carbon content steels. In: International conference on additive manufacturing in products and applications. Springer, Berlin
Malý M et al (2019) Effect of process parameters and high-temperature preheating on residual stress and relative density of Ti6Al4V processed by selective laser melting. Materials 12(6):930
Casati R et al (2018) Effects of platform pre-heating and thermal-treatment strategies on properties of AlSi10Mg alloy processed by selective laser melting. Metals 8(11):954
Danlos Y et al (2008) Combining effects of ablation laser and laser preheating on metallic substrates before thermal spraying. Surf Coat Technol 202(18):4531–4537
Aghasibeig M, Fredriksson H (2012) Laser cladding of a featureless iron-based alloy. Surf Coat Technol 209:32–37
Zhang H et al (2010) Laser cladding of Colmonoy 6 powder on AISI316L austenitic stainless steel. Nucl Eng Des 240(10):2691–2696
Khaled T (2014) Preheating, interpass and post-weld heat treatment requirements for welding low alloy steels, vol 6, pp 1–14
Pradhan A et al (2014) Extreme tunability in aluminum doped zinc oxide plasmonic materials for near-infrared applications. Scientific reports, vol 4, p 6415
Wang W-R et al (2012) Effects of Al addition on the microstructure and mechanical property of AlxCoCrFeNi high-entropy alloys. Intermetallics 26:44–51
Dieter G (1988) Mechanical metallurgy, 3rd edn. McGraw-Hill, London
Wang W et al (2016) Liquid phase separation and rapid dendritic growth of high-entropy CoCrCuFeNi alloy. Intermetallics 77:41–45
Tong C-J et al (2005) Microstructure characterization of Al x CoCrCuFeNi high-entropy alloy system with multiprincipal elements. Metall Mater Trans A 36(4):881–893
Qiu X-W (2013) Microstructure and properties of AlCrFeNiCoCu high entropy alloy prepared by powder metallurgy. J Alloy Compd 555:246–249
Ding C et al (2018) Effects of substrate preheating temperatures on the microstructure, properties, and residual stress of 12CrNi2 prepared by laser cladding deposition technique. Materials 11(12):2401
Author information
Authors and Affiliations
Corresponding author
Editor information
Editors and Affiliations
Rights and permissions
Copyright information
© 2020 The Minerals, Metals & Materials Society
About this paper
Cite this paper
Dada, M., Popoola, P., Mathe, N., Pityana, S., Adeosun, S., Lengopeng, T. (2020). Fabrication and Hardness Behaviour of High Entropy Alloys. In: TMS 2020 149th Annual Meeting & Exhibition Supplemental Proceedings. The Minerals, Metals & Materials Series. Springer, Cham. https://doi.org/10.1007/978-3-030-36296-6_146
Download citation
DOI: https://doi.org/10.1007/978-3-030-36296-6_146
Published:
Publisher Name: Springer, Cham
Print ISBN: 978-3-030-36295-9
Online ISBN: 978-3-030-36296-6
eBook Packages: Chemistry and Materials ScienceChemistry and Material Science (R0)