Nanocrystallization of Cu-Based Bulk Glassy Alloys upon Annealing

Abstract

Cu-based bulk glassy alloy is a new amorphous system developed recently, which has large glass forming ability and relatively low cost (Dai et al., 2006; Fu et al., 2008; Kim et al., 2006; Malekana et al., 2010; Zhang & Zhang, 2008). The tensile fracture strength is much higher than crystals, reaching up to 2,000 to 2,400 MPa, with certain ductility. And compared to Zr-based and Pd-based bulk glassy alloys, the strength of Cu-based bulk glassy alloy is also on the top, which can be used as ultra-high strength structural materials in the future. Until now, many researchers in the world have done a lot of deep studies on Cu-based bulk glassy alloy. But as structural materials, the plastic property of prepared Cubased bulk glassy alloy which has lowers plastic property than steel materials also need to be improved. Therefore, it’s an urgent problem to improve the plasticity and toughness of amorphous alloys. Based on the research of bulk glassy alloy, in recent years, the research on the composite material of bulk glassy and nanocrystalline alloy has been carried out (Barekara et al., 2010; Liu et al., 2009; Xie et al., 2008; Yang et al., 2009; Zhang et al., 2013). Because when the nanocrystalline evenly distributed in the bulk glassy alloy matrix, the properties of bulk glassy alloy can be further optimized, while maintaining high strength and improving the lower plastic. So the application field of high strength structural material can be expanded. In this paper, Cu-based bulk glassy alloy was prepared through copper mold casting method. The nanocrystallization of bulk glassy alloy was obtained by annealing. The annealing process, microstructure and properties of the nanocrystallization were investigated. The preparation of Cu-based bulk glassy-nanocrystalline alloy composite materials on the basis of the theory and technology pISSN 2287-5123·eISSN 2287-4445 http://dx.doi.org/10.9729/AM.2016.46.1.32