Synthesis and microstructural characterization of a novel multicomponent equiatomic ZrNbAlTiV high entropy alloy

2016 ◽  
Vol 124 ◽  
pp. 146-150 ◽  
Author(s):  
B. Vishwanadh ◽  
N. Sarkar ◽  
S. Gangil ◽  
S. Singh ◽  
R. Tewari ◽  
...  
2015 ◽  
Vol 358 ◽  
pp. 533-539 ◽  
Author(s):  
V. Soare ◽  
M. Burada ◽  
I. Constantin ◽  
D. Mitrică ◽  
V. Bădiliţă ◽  
...  

2021 ◽  
Vol 349 ◽  
pp. 02003
Author(s):  
Ioannis Daskalopoulos ◽  
Spyridon Chaskis ◽  
Marianthi Bouzouni ◽  
Pavlos Stavroulakis ◽  
Russell Goodall ◽  
...  

This work deals with the microstructural characterization of two equiatomic high-entropy, low-density alloys (HEA), the AlCrTiV and AlCrTiV-Si7.2. These alloys can serve as potential candidates for advanced applications where high strength and enhanced ductility is demanded. For ensuring high ductility the alloys must contain as minimum as possible hard precipitates. As the strength increase is based on both solid solution and precipitation hardening, the laboratory made alloys were investigated in as-cast and heat-treated conditions. For the heat treatment a high soaking temperature of 1200°C for 8 hours was selected to ensure microstructure homogenization. Micrographic observations of the AlCrTiV and AlCrTiV-Si7.2 samples in the as-cast condition indicated the presence of a dendritic microstructure. Furthermore, chemical micro-analysis showed segregation in the matrix in both samples. This is a critical result as this segregation will lead to heavy precipitation at interdendritic regions, it may sensitize these regions and in the worst-case scenario may cause cleavage fracture in the micro scale, which can trigger brittle fracture during cooling even without the application of deformation. However, the selected heat treatment eliminated the segregation phenomena forcing the alloying elements to be uniformly distributed in the matrix. At the center of the heat-treated AlCrTiV-Si7.2 sample the fragmentation and spheroidization of the intermetallic phase Ti5Si3 was observed. For the same sample, at the mold-sample’s interface, the particles Ti5Si3 were shown to dissolve and form aggregates. Both alloys exhibited high hardness values with small differences between the as-cast and heat-treated conditions, which indicates that the AlCrTiV–Si7.2 high entropy alloy presents high yield strength and may operate at high temperatures without deterioration of the mechanical properties nor unexpected failure.


2016 ◽  
Vol 257 ◽  
pp. 72-75 ◽  
Author(s):  
Monique Calvo-Dahlborg ◽  
Juan Cornide ◽  
Ulf Dahlborg ◽  
Sylvain Chambreland ◽  
Gareth D. Hatton ◽  
...  

According to literature, a High Entropy Alloy (HEA) has close to equimolar composition and forms mostly fcc and/or bcc phases as well as solid solutions, i.e. the elements take random occupations on available lattice sites. In this paper we report studies on HEAs of the CoCrFeNiPd system. All alloys have been found to, contrary to what has been reported earlier in literature, consist of four different phases, three of them of fcc type. The relative amounts of the different phases depend on Pd concentration. The different phases seem to be fully interconnected.


2019 ◽  
Vol 22 (4) ◽  
pp. 1901311 ◽  
Author(s):  
Fatemeh Alijani ◽  
Mohsen Reihanian ◽  
Khalil Gheisari ◽  
Motohiro Yuasa ◽  
Hiroyuki Miyamoto

Materials ◽  
2021 ◽  
Vol 14 (11) ◽  
pp. 3071
Author(s):  
Andri Isak Thorhallsson ◽  
Francesco Fanicchia ◽  
Emily Davison ◽  
Shiladitya Paul ◽  
Svava Davidsdottir ◽  
...  

Geothermal process equipment and accessories are usually manufactured from low-alloy steels which offer affordability but increase the susceptibility of the materials to corrosion. Applying erosion-corrosion-resistant coatings to these components could represent an economical solution to the problem. In this work, testing of two newly developed laser metal deposited high-entropy alloy (LMD-HEA) coatings—CoCrFeNiMo0.85 and Al0.5CoCrFeNi, applied to carbon and stainless steels—was carried out at the Hellisheidi geothermal power plant. Tests in three different geothermal environments were performed at the Hellisheidi site: wellhead test at 194 °C and 14 bar, erosion test at 198 °C and 15 bar, and aerated test at 90 °C and 1 bar. Post-test microstructural characterization was performed via Scanning Eletron Microscope (SEM), Back-Scattered Electrons analysis (BSE), Energy Dispersive X-ray Spectroscopy (EDS), optical microscopy, and optical profilometry while erosion assessment was carried out using an image and chemical analysis. Both the CoCrFeNiMo0.85 and Al0.5CoCrFeNi coatings showed manufacturing defects (cracks) and were prone to corrosion damage. Results show that damage in the CoCrFeNiMo0.85-coated carbon steel can be induced by manufacturing defects in the coating. This was further confirmed by the excellent corrosion resistance performance of the CoCrFeNiMo0.85 coating deposited onto stainless steel, where no manufacturing cracks were observed.


Author(s):  
C. Real ◽  
M.D. Alcalá ◽  
I. Trigo ◽  
I. Fombella ◽  
J.M. Córdoba

2015 ◽  
Vol 21 (S3) ◽  
pp. 2121-2122
Author(s):  
C.D. Gomez-Esparza ◽  
F.J. Baldenebro-Lopez ◽  
J.A. Baldenebro-Lopez ◽  
R. Corral-Higuera ◽  
J. M. Herrera-Ramirez ◽  
...  

Author(s):  
Heena Khanchandani ◽  
Jaibeer Singh ◽  
Priyanka Sharma ◽  
Rupesh Kumar ◽  
Ornov Maulik ◽  
...  

Sign in / Sign up

Export Citation Format

Share Document