scholarly journals Microstructure and Mechanical Properties of the ((CoCrFeNi)95Nb5)100−xMox High-Entropy Alloy Coating Fabricated under Different Laser Power

Metals ◽  
2021 ◽  
Vol 11 (9) ◽  
pp. 1477
Author(s):  
Wenrui Wang ◽  
Qi Sun ◽  
Dingzhi Wang ◽  
Junsong Hou ◽  
Wu Qi ◽  
...  
Keyword(s):  
Laser Beam ◽  
Laser Cladding ◽  
Volume Fraction ◽  
Beam Power ◽  
High Entropy Alloy ◽  
High Entropy ◽  
Laser Cladding Process ◽  
Laser Beam Power ◽  
Interdendritic Phase ◽  
Dendritic Structures

In this paper, the ((CoCrFeNi)95Nb5)100−xMox (x = 1, 1.5 and 2) high-entropy alloy (HEA) coatings were fabricated on the substrate of 45# steel by laser cladding process under different laser beam power. The influence of laser beam power and molybdenum element content on the microstructure and microhardness of the HEA coatings was investigated. Results show that the HEA coatings were composed of face-centered cubic (FCC) phase and Laves phase, had low porosity, and bonded well to the substrate. The Mo1 coating is composed of cellular dendritic structures and columnar dendritic structures. With the increase of molybdenum element content, the columnar dendritic structures disappeared, the grains are refined, and the arrangement of grains is more compact. The volume fraction of the interdendritic phase under the laser beam power of 800 W was small and irregular. After the laser beam power was increased to 1000 W, the volume fraction of the interdendritic phase was increased. Under the laser beam power of 1200 W, the volume fraction of the interdendritic phase was small again. Therefore, the coatings fabricated under the laser beam power of 1000 W had a larger volume fraction of the interdendritic phase and higher microhardness. With the increase in molybdenum content, the grain changed from columnar dendrite to cellular dendrite, and the microhardness of the coating increased. The characteristics of the laser cladding process, the formation of Laves phase, and the fine grain strengthening lead to high microhardness of the coatings.

scholarly journals Parametric investigation and optimization for CO2 laser cladding of AlFeCoCrNiCu powder on AISI 316

2021 ◽  
Vol 40 (1) ◽  
pp. 265-280
Author(s):  
Jyoti Menghani ◽  
Akash Vyas ◽  
Satish More ◽  
Christ Paul ◽  
Amar Patnaik
Keyword(s):  
Laser Cladding ◽  
Laser Scanning ◽  
Wear Behavior ◽  
Scanning Speed ◽  
Beam Power ◽  
High Entropy Alloy ◽  
Operating Parameters ◽  
Test Duration ◽  
High Entropy ◽  
Pin On Disk

Abstract The purpose of the current investigation is to analyze the effect of the operating parameters of laser-assisted cladding process on clad height, clad depth, clad width and the percentage dilution in a cladding of AlFeCuCrCoNi high-entropy powder on SS-316 through CO2 laser and to optimize the cladding process parameters for optimum dilution. The experiments were designed by the full factorial method and analyzed by ANOVA. The analysis results indicate that dilution is most influenced by scanning speed followed by the powder feed rate. The outcomes of the single clad profile in terms of dilution, microhardness, composition and the microstructures produced in various cladding conditions are investigated briefly, and through which the optimum set of laser cladding operating parameters for maximum hardness of the clad material is determined. The optimum cladding conditions in the experimental range were obtained at 4 g/min powder feeding rate, 500 mm/min laser scanning speed and 1.1 kW laser beam power through multi-response optimization. Furthermore, the multi-track coating with 60% overlapping ratio was deposited using optimized parameters. The wear behavior of multi-track coating was determined using pin on disk wear apparatus with applied load of 20 N, sliding speed of 300 RPM and test duration of 15 min. The pin on disk wear test results indicates that the friction coefficient of SS-316 is larger than that of high-entropy alloy cladded SS-316. The wear resistivity of SS-316 improved by 40.35% after laser-assisted high-entropy alloy coating, which confirms that the laser cladding layer plays an essential role in enhancing the wear resistance capability of austenite steel.

Characterization of Laser Beam Welded Al0.5CoCrFeNi High-Entropy Alloy

2018 ◽  
Vol 775 ◽  
pp. 448-453 ◽  
Author(s):  
R. Sokkalingam ◽  
K. Sivaprasad ◽  
V. Muthupandi ◽  
Muthukannan Duraiselvam
Keyword(s):  
Laser Beam ◽  
Fusion Zone ◽  
Laser Beam Welding ◽  
Dendritic Structure ◽  
Specific Yield ◽  
Vacuum Arc ◽  
Beam Power ◽  
High Entropy Alloy ◽  
High Entropy ◽  
Weld Fusion Zone

High-entropy alloys (HEA), a new generation alloy system offer superior mechanical properties with solid solution strengthening. AlxCoCrFeNi-HEA is one such system being received more attention because of its specific yield strength and ductility. In the present work, Al0.5CoCrFeNi-HEA was prepared by vacuum arc melting. The laser beam welding (LBW) was carried out on 1mm thick forged and homogenized HEA, with a beam power of 1.5 kW and at a traverse speed of 600 mm/min. The microstructural features of different regions of the weld were studied using scanning electron microscopy. The homogenized Al0.5CoCrFeNi-HEA have shown equiaxed grains of average size 60 μm. The weld metal showed a typical weld fusion zone microstructure with dendritic structure with a reduction in BCC phase due to minimal Al and Ni segregation ratio at interdendrites. Micro-chemical analysis with energy dispersive spectroscopy confirmed that there was no major segregation of elements in the weld fusion zone. The microhardness survey performed across the weld evidenced a reduction in hardness, as a consequence of significant reduction in Al-Ni rich hardening factor.

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