Effect of minor addition of Zr on the oxidation behavior of Ti-Cu metallic glasses

Review on the Research and Development of Ti-Based Bulk Metallic Glasses

“…It is found that Ti-based BMGs possess relatively small S values compared with other BMGs, implying a relatively low thermoplastic formability. Moreover, as titanium is a very active element, during the heating process in air, the oxidation is more serious compared with Pd-, Au-, and Pt-based BMGs, which is harmful to the thermoplastic forming [213][214][215]. In order to perform the thermoplastic forming of Ti-based BMGs, especially in air, it is necessary to first attempt composition optimization in order to develop novel Ti-based BMGs with better thermoplastic formability and oxidation resistance.…”

High thermal stability of the amorphous oxide in Ti44.5Cu44.5Zr7Be4 metallic glass

“…[33][34][35][36][37] Therefore, the aim of the present study is to investigate the formation of the amorphous oxide layer by addition of minor alloying element in Ti-Cu-Zr metallic glass. Ti 46.5 Cu 46.5 Zr 7 metallic glass is known to have a reasonably wide SCL region of 32 K. 39 Our preliminary study shows that an inter-mixed crystalline TiO 2 + ZrO 2 layer forms, when Ti 46.5 Cu 46.5 Zr 7 metallic glass is continuously heated up to the temperature of the SCL region. 39 In the present study, beryllium (Be) was selected as the minor alloying element since it has been shown that the addition of Be widens the SCL region in some metallic glass systems.…”

“…Ti 46.5 Cu 46.5 Zr 7 metallic glass is known to have a reasonably wide SCL region of 32 K. 39 Our preliminary study shows that an inter-mixed crystalline TiO 2 + ZrO 2 layer forms, when Ti 46.5 Cu 46.5 Zr 7 metallic glass is continuously heated up to the temperature of the SCL region. 39 In the present study, beryllium (Be) was selected as the minor alloying element since it has been shown that the addition of Be widens the SCL region in some metallic glass systems. 20,40,41 It has also been shown that Be is an effective stabilizer of amorphous oxide.…”

“…The final weight gain at 1073 K was ∼0.15 mg/cm 2 . When compared with the result from melt-spun Ti 46.5 Cu 46.5 Zr 7 (weight gain at 1073 K: ∼0.24 mg/cm 2 ), 39 the final weight gain at 1073 K is significantly reduced, and the oxidation in the SCL region is suppressed. It is expected that higher thermal stability of the oxide layer with an amorphous structure can enhance the oxidation resistance when continuously heated up to 1073 K. Highly dense atomic structure in the amorphous oxide layer limits the diffusion rate of oxygen and metal ions in the oxide layer, therefore, enhancing the oxidation resistance.…”

“…The glass transition temperature (T g ) and crystallization onset temperature (T x ) were 630 K and 687 K, respectively, indicating that the supercooled liquid region (∆T x ) significantly increases up to 57 K with the addition of Be, when compared with 32 K in melt-spun Ti 46.5 Cu 46.5 Zr 7 . 39 It is generally known that the additional alloying elements for enhancement of the GFA can be selected based on three empirical rules: largely negative heat of mixing between the constituent elements, larger atomic size difference and multi-component system. 42 The enthalpy of mixing of Be with Ti, Cu, Zr is -30, 0 and -43 kJ/mol, respectively.…”