Abstract:Zr47–xCu46Al7Yx(x=3~8) bulk metallic glasses (BMGs) were prepared by injection in copper mould with arc melting. The effect of Y content on the glass-forming ability (GFA), microstructures, fractured surfaces and mechanical properties of the alloys were investigated by using X-ray diffraction (XRD), differential scanning calorimetry (DSC), scanning electron microscope (SEM), compression tests and hardness tests, respectively. Results show: Y content has evident effect on the GFA and mechanical properties, the BMGs with 4~7at%Y contents only contain amorphous phases and possess a larger supercooled liquid region ΔTx with value of 56~71K and a better reduced glass transition temperature Trg with value of 0.665~0.678, but very few crystalline phases appear on the BMGs with 3 and 8at%Y contents. The BMGs possess better mechanical properties with compression strength of 1803-1899MPa and Vickers hardness of 5.22~5.39GPa, the BMGs with the better GFA correspondingly possess the better mechanical properties. In compression test, the BMGs happen brittle fracture by pure elastic deformation way, and all fractured surfaced are flat and smooth with typical vein-like morphologies.