Zirconium based bulk metallic glass-Better resistance to slurry erosion compared to hydroturbine steel

The slurry erosion behavior of a zirconium based bulk metallic glass, Zr44Ti11Cu10Ni10Be25, was evaluated in this study. Slurry erosion tests were carried out using a non-circulating type test rig at impingement angles of 30 degrees, 60 degrees, and 90 degrees. Commonly used hydroturbine steel was evaluated under the same test conditions. At 30 degrees impingement angle, the metallic glass demonstrated nearly 2.6 times higher erosion resistance compared to the steel. At normal impingement, the metallic glass was marginally better. Lower erosion rates of the bulk metallic glass at oblique impingement angles was attributed to its significantly higher hardness and deformation induced partial devitrification. For normal impingement, material was removed in the form of fragments from highly strained platelets due to limited plasticity of bulk metallic glasses. The metallic glass demonstrated a brittle mode of erosion with higher erosion rate at higher angle of impingement. In contrast, hydroturbine steel showed ductile mode of erosion under the same test conditions. (C) 2013 Elsevier B.V. All rights reserved.