Temperature Dependence of the Wettability between Glass‐Forming Alloy Zr₅₅Cu₃₀Al₁₀Ni₅ and Polycrystalline ZrO₂

Abstract

Wetting of ZrO2–3 mol% Y2O3 substrates by a molten Zr55Cu30Al10Ni5 bulk metallic glass forming alloy was studied using a modified sessile drop method at 1133–1473 K in a high vacuum and their interfacial chemistry was investigated. The time variation in the contact angle shows anomalous temperature dependence at 1133–1293 K, i.e., the initial contact angle gradually decreases while the final contact angle increases with increasing temperature. In the range of 1293–1473 K, the contact angle sharply decreases in the initial stage but shows little change in the subsequent long isothermal duration. A distinct reaction layer consisting of substoichiometric ZrO2−x was developed at the interface. The remarkable temperature dependence of the wettability is due to the competition among the adsorption and accumulation of the active atoms such as Zr at the interface, the interfacial reaction, and the release of oxygen from ZrO2. The adsorption of Zr at the triple junction, particularly enhanced by the structural transition of ZrO2, plays an important role in promoting the wettability. In contrast, the oxygen release leads to the oxidation of the active atoms and ready pinning of the triple line, thus deteriorating the wettability. The interfacial reaction may promote the wetting as well, but its role is limited because on the one hand, it consumes the adsorbed active Zr atoms, and on the other, the pinning of the triple line due to the compositional oxidation considerably weakens its function.

Wetting behavior and brazing of titanium‐coated SiC ceramics using Sn0.3Ag0.7Cu filler

“…For the XPS analysis of bombarded bombarded sample shown in Figure C, the peaks at 459.3 eV indicating the presence of Ti 3+ species and the increasing intensity of peak at 453.1 eV demonstrated the increasing content of pure Ti. The Ti2 p core levels shifted to lower binding energies indicating the presence of an anoxic surface layer inside the deposited film . Besides, the intensity of peaks (453.1 eV) increased dramatically compared to the coated sample, indicating the rising of fraction of pure Ti.…”

“…The Ti2p core levels shifted to lower binding energies indicating the presence of an anoxic surface layer inside the deposited film. 27 Besides, the intensity of peaks (453.1 eV) increased dramatically compared to the coated sample, indicating the rising of fraction of pure Ti. This phenomenon suggested that the coated Ti is more metallic near the Ti/SiC interface than the coated film surface.…”

Synthesis of bioinspired ice-templated bulk metallic glass-alumina composites with intertwined dendritic structure

“…These results reveal that the reaction shown by Eq. (1) was more favorable at 1000 ℃, leading to the local enrichment of Al at the interface and thus a decrease in the FA of the BM -forming melt.Furthermore, the formation of ZrO2 on the alumina also leads to weak interfacial bonding since the wettability of ZrO2 by Zr-based BMs significantly deteriorates as the temperature increases from 880 to 1000℃[27]. The reaction product ZrO2 was barely observed and the amount of the Al-rich intermetallic compound was small in the composite prepared at 880℃, implying that the chemical reaction can be suppressed by lowering infiltration temperature, thereby leading to strong interfacial bonding.…”