Glass-forming Ability And The Mechanical Properties Of Fe-based Bulk Metallic Glasses

In this paper, a series of Fe-based amorphous alloys were prepared by using raw industrial materials. The microstructure and phases constituent were investigated by employing scanning electron microscopy (SEM) and X-ray diffraction (XRD) methods. The thermodynamic characteristic and mechanical properties of amorphous samples has been obtained by means of differential scanning calorimetry (DSC) and electronic universal tester.The result shows that, the partial replacement of Fe with a certain amount Nb in Fe₄₈Cr₁₅Mo₁₄C₁₅B₆Y₂ alloy will increases its glass-forming ability and compressive fracture strength significantly. Among them, the Fe₄₆Cr₁₅Mo₁₄Ci₅B₆Y₂Nb₂ alloy has the best glass-forming ability and the critical size for glass formation has reached 7mm in diameter; the Fe₄₇Cr₁₅Mo₁₄C₁₅B₆Y₂Nb₁ alloy has the best compressive fracture strength of 3645.7 MPa.The glass forming ability and mechanical properties of Fe_64.5-x-yCo_xMo₁₄C₁₅B₆Er_0.5M_y (x=3, y=2, 3; x=5, y=2, 3; M=Ni, Nb) alloys were studied. The results shows that the Fe_64.5-x-yCo_xMo₁₄C₁₅B₆Er_0.5Ni_y (x=3, y=2, 3; x=5, y=2, 3) and Fe_59.5Co₅Mo₁₄C₁₅B₆Er_0.5Nb₂ alloys can be formed a bulk metallic glass (BMG) with a diameter of 2mm. The compressive tests show that the Fe_58.5Co₃Mo₁₄C₁₅B₆Er_0.5Ni₃ amorphous alloys exhibit not only high fracture strength (3890MPa), but also large plastic deformation behavior (plastic strains are 2.7%). While almost no plastic deformation was found for the Nb containing FeCoMoCBEr amorphous alloys.The effect of Er addition on the glass forming ability and mechanical properties of Fe₆₅Mo₁₂C₁₅B₆Ni₂ alloys was investigated. The compressive tests show that Fe_64.5Mo₁₂C₁₅B₆Er_0.5Ni₂ alloy exhibits better compressive fracture strength of 3350.1MPa and plastic deformation of 2.6%, respectively. The fracture surfaces of Fe₆₄Mo₁₂C₁₅B₆Er₁Ni₂ alloy show many discontinuous venous patterns. The Fe₆₃Mo₁₂C₁₅B₆Er₂Ni₂ alloy has the best glass-forming ability and the critical size for glass formation has reached 3mm. The SEM results show that the fracture surfaces for the samples with plastic deformation present obviously tearing and viscous flow.