Synthesis of large-size nanocrystal-toughened Cu-based bulk metallic glasses with excellent plasticity by controlling solidification

1)通过成分优化，Cu-Zr-Al-Ag合金的非晶形成能力显著增强。制备出粒径为2 ~ 5mm的Cu-Zr-Al-Ag块状非晶合金，Ta颗粒（40μm）分布均匀。复合材料具有较高的强度和不同寻常的塑性。Ta粒子为多个剪切带的形成埋下种子，阻断剪切带的传播，导致剪切带呈网状均匀分布。2)采用铜模铸造法制备了尺寸为5 ~ 10nm的大尺寸Zr-Cu-Al-Fe块状非晶合金。复合材料具有高屈服强度和大塑性的特点。阐明了新型大块玻璃复合材料具有大塑性的机理。

1) Glass-forming ability of Cu-Zr-Al-Ag alloys was significantly enhanced by the composition optimum. The Ta particles (40μm) homogenously distributed the Cu-Zr-Al-Ag bulk glassy alloys with diameters of 2-5mm were synthesized. The composites showed high strength and unusual plasticity. Ta particles seed the initiation of multiple shear bands and block the shear band propagation, leading to a net-like homogeneous distribution of the shear bands.2) The large-size Zr-Cu-Al-Fe bulk glassy alloys containing nanocrystals with size of 5-10nm were obtained by copper mold casting. The composites exhibited a combination of high yield strength and large plasticity. The mechanism for the large plasticity of the new bulk glassy composites is elucidated.