Effect of Ge addition on mechanical properties and fracture behavior of Cu–Zr–Al bulk metallic glass

Effect of the addition of a small amount of Ge on mechanical properties and fracture behavior of Cu 50Zr 43Al 7 (at.%) bulk metallic glass were studied. The Cu 50Zr 43Al 7 alloy has a surprising glass-forming ability (GFA), and the glassy rods up to 4 mm in diameter can be formed. Partial addition of Ge causes the crystalline phases precipitate in the glassy matrix of (Cu 50Zr 43Al 7) 100− x Ge x ( x = 0, 1, 2) rods with a diameter of 4 mm. In uniaxial compression, Cu 50Zr 43Al 7 bulk metallic glass exhibit high strength of 1692 MPa and very limited plasticity of 0.05%. When Ge increases from 0 to 2 at.%, the strength decreases, but plastic strain increases about 2.5%. Fracture surface and shear bands of samples were investigated by scanning electron microscopy (SEM).