A simple strategy for fabrication of an FCC-based complex concentrated alloy coating with hierarchical nanoprecipitates and enhanced mechanical properties. (15th October 2019)

• Record Type: Journal Article
• Authors: Wang, Mingliang; Cui, Hongzhi; Zhao, Yuqiao; Wang, Canming; Wei, Na; Zhao, Yong; Zhang, Xue; Song, Qiang
• Is Part Of: Materials & design. Volume 180(2019)
• Publication Date: 2019-10-15
• Subjects: Complex concentrated alloy coating -- Spark plasma sintering -- Hierarchical nanoprecipitates -- Precipitation strengthening -- Mechanical properties; Materials -- Periodicals; Engineering design -- Periodicals; Matériaux -- Périodiques; Conception technique -- Périodiques; Electronic journals; 620.11
• DOI: 10.1016/j.matdes.2019.107893
• Languages: English
• ISSNs: 0264-1275

Abstract

Abstract: An increasing number of recent studies have indicated that the best balance of mechanical properties of a high-entropy alloy (HEA) needed to meet the requirements of practical structural applications require to produce second precipitates in an HEA matrix. This type of alloy is more appropriately classified as a complex concentrated alloy (CCA) rather than an HEA. Here, we report a simple strategy for the fabrication of CCA coatings with high mechanical properties. In this strategy, the face-centred cubic (FCC)-based Co25 Cr25 Cu12.5 Ni25 Al12.5 (at.%) system was chosen, and spark plasma sintering was first used to prepare the Co25 Cr25 Cu12.5 Ni25 Al12.5 CCA clad layer directly on a Q235 substrate from simple mixed powders. Our results show that the CCA coating was fabricated successfully on the substrate and that the clad layer exhibited a dense microstructure, a low dilution ratio and good metallurgical bonding with the substrate. A high density of hierarchical intragranular nanoprecipitates was contained in the clad layer. Precipitation strengthening, as one of the main strengthening mechanisms, contributes to a microhardness value of 455 HV for the clad layer, which is much higher than those of most reported FCC-structured HEAs, even some BCC-structured refractory HEAs and several BCC-based HEAs with high Al contents. Graphical abstract: Unlabelled Image Highlights: A simple and effective strategy was proposed for fabrication of complex concentrated alloy coatings. The complex concentrated alloy coating exhibits dense microstructures and good metallurgical bonding with substrate. A high density of hierarchical intragranular nanoprecipitates was contained in clad layer. Microhardness of clad layer is higher than those of most reported face-centred cubic-based high-entropy alloys.