Process Optimization of High Entropy Alloys by Laser Additive Manufacturing

Dada, Modupeola; Popoola, Patricia; Mathe, Ntombi; Pityana, Sisa; Adeosun, S. O.; Aramide, Fatai Olufemi; Lengopeng, Thabo

doi:10.22541/au.158049508.81554322

Cited by 8 publications

(9 citation statements)

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“…The RSM was used to optimize the experimental design using laser power, scan speed, and scan spacing as parameters. These parameters were varied simultaneously over several sets of experimental runs to identify the best process parameters to improve the output response [15].…”

Section: Resultsmentioning

confidence: 99%

Selective Laser Melting of High Relative Density and High Strength Parts Made of Minor Surface Oxidation Treated Pure Copper Powder

Yang

Guo

et al. 2021

Metals

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Pure Copper (Cu) is very difficult to prepare using selective laser melting (SLM) technology. This work successfully prepared the pure Cu with high relative density and high strength by the SLM technology using a surface oxidation treatment. The gas-atomized pure Cu powder was used as the feedstock in this work. Before the SLM process, the pure Cu powder was initially handled using the surface oxidation treatment to coat the powder with an extremely thin layer of Cu2O. The SLMed highly dense specimens contain α-Cu and nano-Cu2O phases. A relationship between the processing parameters (laser power (LP), scanning speed (SS), and hatch space (HS)) and density of Cu alloy in SLM was also investigated. The microstructure of SLMed Cu consists of fine grains with grain sizes ranging from 0.5 to ~30 μm. Tensile testing and detailed microstructural characterization were performed on specimens in the as-SLMed and pure copper state specimens. The mechanical property experiments showed that the specimens prepared by SLM technology containing nano-oxide phases had higher yield strength and tensile strength than that of other SLM-built pure copper. However, the elongation was remarkably decreased compared to other SLM-built pure copper, due to the fine grains and the nano-oxides.

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Section: Resultsmentioning

confidence: 99%

Selective Laser Melting of High Relative Density and High Strength Parts Made of Minor Surface Oxidation Treated Pure Copper Powder

Yang

Guo

et al. 2021

Metals

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“…The BCC structure has a lower atomic packing density than the FCC, resulting in the accommodation of larger solute atoms like Al [14]. Suggesting that constituent elements significantly influence the phase formation of the as-built AlCoCrCuFeNi high-entropy alloy.…”

Section: Microstructure Analysismentioning

confidence: 99%

“…Yu et al [14] examined the tribological behaviour of two high-entropy alloy systems (AlCoCrFeNiTi 0.5 and AlCoCrCuFeNi) prepared via arc melting under 90% hydrogen peroxide solution for propulsion applications because previous studies in the literature showed that the AlCoCrCuFeNi alloy system has good tribological properties in this solution [15]. The tests were carried out using a disc comprising stainless steel, SiC, and ZrO 2 ceramics as counterparts on a pin-on-disc tribo-tester at room temperature.…”

Section: Introductionmentioning

confidence: 99%

Wear characteristics of laser-deposited AlCoCrCuFeNi high entropy alloy with finite element analysis

Dada

Popoola

Mathe

et al. 2022

Beni-Suef Univ J Basic Appl Sci

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Background Wear is a destructive phenomenon and one of the principal causes of material failure in moving components during surface interaction while in service. AlCoCrCuFeNi high-entropy alloy with its many properties is a potential material for aero-engine applications attributed to its outstanding relatively lightweight, high strength, good thermal, oxidation, and corrosion resistance properties. Hence, the investigation into the tribological behaviour of AlCoCrCuFeNi high-entropy alloys is essential to reduce maintenance costs and prolong the service life of this advanced material for aerospace applications. Most AlCoCrCuFeNi high-entropy alloy compositions were fabricated via arc melting, which has been reported to have defects attributed to slow solidification, consequently reducing the mechanical properties of the alloy with limited reports on other fabrication methods. Therefore, there is a need for the use of advanced manufacturing techniques for fabricating these alloys to improve the tribological properties. In this study, AlCoCrCuFeNi high-entropy alloy was fabricated via laser metal deposition. The influence of the laser processing parameters, rapid solidification, and the applied load on the tribological properties of the as-built alloys under dry conditions has been studied for aerospace applications. The counter ball rolling friction analysis was also investigated using COMSOL Multiphysics. Results The results showed that at a high laser power of 1600 W and a scan speed of 12 mm/s, the lowest wear rates and highest hardness values were observed. The average coefficient of friction at room temperature was 0.1 and 0.3 at a speed of 21 m/s. The dominant wear mechanism at room temperature was abrasive wear as the wear rate increased linearly with an increase in load from 10 to 20 N. The scan speed had the most significant influence on the wear behaviour of the as-built high-entropy alloy attributed to the rapid rate of solidification which occurs at higher scan speeds. Conclusions The study examines the wear characteristics of high-entropy alloys fabricated via laser deposition technique in comparison with those fabricated via conventional routes. Although there were similarities in the phase structures of both techniques, the results showed that the wear resistance of the laser-deposited high-entropy alloy was comparatively higher than the same alloy prepared via conventional methods. Laser additive manufacturing was concluded to be a more successful method in fabricating high-entropy alloys.

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“…In the nanoindentation test, the hardness properties were obtained from the ܲ-ℎ profile (Fig. 2) using the Oliver-Pharr method [10] as per equation ( 1) below,…”

Section: Hardnessmentioning

confidence: 99%

Effect of 60% thickness reduction of Sn-Cu solder alloy on localized micromechanical properties via nanoindentation approach

Yusoff

Bakar

Jalar

2022

J. Phys.: Conf. Ser.

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The relationship between a process and mechanical properties are important in understanding the behaviour of a material under certain conditions. This indicate that mechanical properties of the materials can be modified through certain processing. Hence, this paper investigates the effect of 60% thickness reduction of Sn-Cu alloy in thermomechanical treatment on the localized micromechanical properties. A bar-shape of Sn-Cu solder alloy is subjected to heat treatment at 30°C, 60°C, 90°C, 120°C and 150°C for 20 minutes, followed by 60% thickness reduction via compression process. Sample without compression process was used as control sample. Nanoindentation approach was used to characterize the localized micromechanical properties of the samples. The results show the hardness value for control samples reduced approximately 56%, from 181 MPa at 30°C to 79 MPa at 150°C. Reduced modulus of control sample has shown similar decreasing trend from 149 GPa at 30°C to 85 GPa at 150°C, approximately 43% changes. Lower changes in hardness and reduced modulus observed for thermomechanical treated sample approximately 20% and 18%, respectively. These findings show that thermomechanical treatment has given significant effect on the localized micromechanical properties of Sn-Cu solder alloy.

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Process Optimization of High Entropy Alloys by Laser Additive Manufacturing

Cited by 8 publications

References 0 publications

Selective Laser Melting of High Relative Density and High Strength Parts Made of Minor Surface Oxidation Treated Pure Copper Powder

Selective Laser Melting of High Relative Density and High Strength Parts Made of Minor Surface Oxidation Treated Pure Copper Powder

Wear characteristics of laser-deposited AlCoCrCuFeNi high entropy alloy with finite element analysis

Effect of 60% thickness reduction of Sn-Cu solder alloy on localized micromechanical properties via nanoindentation approach

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