Glass Transition Kinetic Property And Corrosion Property Research Of Bulk Glassy Zr-Al-Ni-Cu (Nb,Ti) Alloy

Since the first synthesis of an amorphous alloy in Au-Si system by rapid solidification in 1960, a great number of amorphous alloys have been prepared up to date. Bulk metallic glasses (BMG) developed about ten years ago, known as promising engineering materials, offer new opportunities for engineering applications and the fundamental study on the nature of metallic glasses. These three dimensional metallic glasses with much higher thermal stability with respect to crystallization in the undercooled liquid state compared to conventional metallic glasses make experimental investigations of the glass transition and the undercooled liquid state of a metallic system possible that were not feasible before. This work mainly performs the investigation of the glass transition kinetic property and corrosion property research of bulk glassy Zr-Al-Ni-Cu(Nb,Ti) alloy.Firstly, the kinetic property at glass transition process of ZrAlNiCu(Nb,Ti) amorphous alloys was systematic investigated by DSC experiment method. the activation energy(E) at glass transition temperature was much smaller than tradition amorphous alloys and have different magnitude trend compare to AE value at Tx. These revealed bulk amorphous alloys special structure characteristics and the reason of its big glass-forming ability. The VFT fits to the experimental data are given by the full curves and the fragility parameter m value was calculated about 30, reflected its "strong" liquid property at deep-undercooled region. the B value of Lasocka function atom activation energy and glass fragility parameter revealed close relationship between kinetic behavior at glass transition and glass-forming ability, so it could be used as important judgment method on GFA.Furthermore, the corrosion resistance of Zr-Al-Ni-Cu (Nb) bulk amorphous alloys was systematically investigated in this paper. Unlike what has been generally believed, the corrosion resistance of Zr-based bulk amorphous alloys could not be considered to be excellent at any situation, whereas it is affected by many factors such as the kind of corrosive medium, solution concentration and the alloy composition. We found Zr-Al-Ni-Cu bulk amorphous alloys were seriously corroded in HCl solution in comparison with their excellent corrosion resistance at other acid, alkali and salt circumstances for passivating. Its resistance ability against the chlorine ion induced pit corrosion could be greatly improved by the addition of Nb element.