The Effect of Ag Addition on the Enhancement of the Thermal and Mechanical Properties of CuZrAl Bulk Metallic Glasses

Abstract

Abstract:In this study, the thermal and mechanical properties of Cu 50−x Zr 43 Al 7 Ag x (x = 0, 3, 4, 5, 6) bulk metallic glasses (BMGs) are investigated by using an X-ray diffractometer (XRD), a differential scanning calorimeter (DSC), differential thermal analysis (DTA), a Vickers hardness tester, a material test system (MTS), scanning electron microscopy (SEM), and transmission electron microscopy (TEM). Cu 50−x Zr 43 Al 7 Ag x (x = 0, 3, 4, 5, 6) BMGs were made by arc-melting and an injection casting process. The results revealed that the glass transition temperature (T g ) and the crystallization temperature (T x ) of CuZrAl alloy decreased with the Ag addition. Hence, the supercooled liquid region and γ of Cu 45 Zr 43 Al 7 Ag 5 alloy increased to 76 K and 0.42, respectively. The thermal stability and glass forming ability of CuZrAlAg BMG alloys were enhanced by the microalloyed Ag content. The room temperature compressive fracture strength and strain measured of Cu 47 Zr 43 Al 7 Ag 3 were about 2200 MPa and 2.1%, respectively. The distribution of vein patterns and the formation of nanocrystalline phases on the fracture surface of Cu 47 Zr 43 Al 7 Ag 3 alloy can be observed by SEM and TEM to be significant, indicating a typical ductile fracture behavior and an improved plasticity of alloys with the addition of microalloyed Ag from 0 to 6 atom %.

Effect of Sample-Size on the Compression Deformation Behavior of a CuZr-Based Bulk Metallic Glass Composite

“…Hence, the 3 mm sample showed lower yield strength than the other two samples. Another reason for the low yield strength of the 3 mm sample was its strain incompatibility, which appeared between the glassy matrix and the crystalline phase during the plastic flow process and weakened the interface of the sample, leading to its failure [30]. The free volume of an alloy facilitates the migration of atoms in it upon deformation by force [20].…”

Atomic Structure of Cu49Hf42Al9 Metallic Glass with High Glass-Forming Ability and Plasticity

“…Careful observation of high-resolution transmission electron microscopy (HRTEM) is carried out on the compressed sample. No detectable crystalline clusters were observed in either shear bands or the matrix of Cu 49 Hf 42 Al 9 MG, indicating that the high plasticity of this MG is originated from the amorphous structure itself, other than introducing some composite structures or nano-crystallites as adopted by some MGs to improve the plasticity [16,17]. As a demonstration, Fig.…”

Structure and Properties of Zr-Based Bulk Metallic Glasses in As-Cast State and After Laser Welding

“…Amorphous materials have a lower electrical conductance than the crystalline alloys with the same chemical composition. For this reason, BMGs can be applied as functional materials and materials having favorable (desired) characteristic structures [ 4 , 5 , 6 , 7 , 8 , 9 ].…”