Cu45Zr45Al5Ag5非晶合金之空氣氧化行爲研究

Air-oxidation of a Cu45Zr45Al5Ag5 Bulk Metallic Glass

高佩琴(P. C. Kao) ； 任一飛(I. F. Jen) ； 開物(W. Kai)

《防蝕工程》 23卷2期 (2009/06) Pp. 135-142

https://doi.org/10.6376/JCCE.200906.0135

摘要

本研究探討銅鋯基Cu45Zr45Al5Ag5（以下簡稱CZ45）非晶合金在375℃~500℃空氣下的氧化行爲。研究結果顯示，銅鋯基非晶合金的氧化動力學皆遵守兩段或三段式拋物線律（依溫度高低而異），而非晶的氧化反應速率常數(k(下標 p))與溫度呈現不規則之變化；即在過冷液態區間，k(下標 p)值隨溫度上升而加快，但在450℃以上時，卻有相反的趨勢。氧化後的氧化生成物以正方晶體的ZrO2(t-ZrO2)和CuO爲主，另外有少量的單斜及斜方的ZrO2（m-和o-ZrO2）以及α-Al2O3（只有在500℃生成）。此外，當溫度低於玻璃轉換溫度(T(下標 g))下時，基材仍保有非晶狀態，但當溫度升高時，非晶合金會先氧化後結晶的相變化發生，使基材轉變爲CU10Zr7和ZrAl兩種結晶相。

關鍵字

銅鋯基非晶合金 ； ZrO2 ； CuO ； α-Al2O3

並列摘要

The oxidation behavior of a Cu45Zr45Al5Ag5 bulk metallic glass (CZ45) was studied over the temperature range of 375~500℃ in dry air. The oxidation kinetics of the glassy alloy generally followed a two- to three-stage parabolic rate law, and the steady-state parabolic rate constants (k(subscript p) values) fluctuated with temperature. The k(subscript p) values increased with increasing temperature, when it was in the supercooled region; however, those values decreased with increasing temperature at T＞450℃. The scales formed on the CZ45-BMG consisted mostly of tetragonal-ZrO2(t-ZrO2), CuO, minor amounts of monoclinic-and orthorhombic-ZrO2, (m-and o-ZrO2), and α-A1203 (only detected at 500℃). In addition, the glassy alloy underwent a pre-oxidation process, followed by a phase transformation after the oxidation at T＞400℃. The amorphous substrate remained unchanged at temperatures below the glass-transition temperature (T(subscript g)), while a dual-phase structure of Cu10Zr7 and ZrAl was developed after the oxidation at higher temperatures, indicating the crystallization of the amorphous substrate.

並列關鍵字

Cu45Zr45Al5Ag5 BMG ； t-ZrO2 ； CuO ； α-Al2O3