【摘要】 采用射流铸造法在水冷铜模中制备出成分为Zr52.5Cu30-xNi5.5Al12Nbx(x=0,3)的块体非晶合金。x=0时,样品为完全非晶结构;x=3时,试样的组织为非晶基体上均匀分布着尺度为20nm的富含Zr和Nb的成分偏聚区,同时富集区内镶嵌着尺寸为5nm左右bcc结构的Zr-Nb固溶体纳米颗粒。Zr52.5Cu27Ni5.5Al12Nb3合金的强度较具有完全非晶结构的Zr52.5Cu3027Ni5.5Al12合金有明显的提高:断裂强度由1600MPa增加到1964MPa。非晶基体上析出的纳米颗粒和成分偏聚增加了剪切变形的阻力。同时,基体变形由单滑移(x=0)转变为多滑移(x=3),并且滑移相互交错,避免了由于不均匀形变造成的提前脆断,提高了基体的强度。更多还原

【Abstract】 Bulk Zr52.5Cu30-xNi5.5Al12Nbx (x=0, 3) metallic glass was prepared by using a copper mold casting method. When x=0, the sample structure is amorphous; when x=3, the sample consists of the particles rich in Zr and Nb with a size of 20 nm and dispersed homogeneously in amorphous matrix, in which some bcc Zr-Nb solid solution nanoparticles of 5 nm were embedded. The toughness of Zr52.5Cu27Ni5.5Al12Nb3 amorphous alloy was significantly improved as compared with the Zr52.5Cu30Ni5.5Al12 alloy with monolithic amorphous structure. The compress fracture strength (σf) is 1600 MPa at x=0, and increases up to 1964 MPa at x=3. These nanocrystallines and the regions rich in Zr and Nb acted as the resistant medium against shear deformation, leading to the increase in the toughness. The deformation mode of sample changes from single slip (when x=0) to multiple slip (when x=3), and a number of slip bands occur crosswise and interfere each other, so that the brittle failure of inhomogeneous deformation can be retarded.更多还原