Pengaruh Waktu Pemanasan (Anil) terhadap Ketahanan Korosi pada Gelas Metalik Berbasis Zirkonium

Abstract

The effects of annealing time on the corrosion resistance of a Zr-based bulk metallic glass (BMGs) were studied. The Zr 48 Cu 36 Al 8 Ag BMGs annealed at the temperatures of 471 oC for 0, 23 and 27 min respectively. The partially and fully crystallized was identified by differential thermal analysis (DSC) and by X-ray diffraction (XRD). The corrosion resistances of those BMGs was identified by open circuit potential (OCP), Tafel plot (TP), dan cyclic anodic potentiodynamic polarization (CAPD). The results show that the as-cast of Zr 8 48 Cu 36 Al BMGs (0 min, full amorphous) has higher corrosion resistance than that of the annealing specimen for 23 and 27 min, while the fully crystallized specimen (27 min) has worst corrosion resistance when compared to the other samples in 0.1 M NaCl solution. The improvement of the corrosion resistance for as-cast (0 min) is better than annealed specimen (23 and 27 min), because the as-cast does not have defects like grain boundary (full amorphous). When the annealing time is longer (27 min), the crystallites grow up (more boundary regions), therefore increasing the susceptibility to the localized corrosion.

Keywords: Metallic glass, Zr-Cu-Al-Ag, corrosion, NaCl