Wetting, Adhesion and Adsorption in Al-Si/(0112) α-Alumina System at 1723 K

Abstract

The wetting of (01 " 1 12) -Al 2 O 3 single crystals by Al-Si alloys in the full composition range was studied by an improved sessile drop method in a reducing Ar-3%H 2 atmosphere at 1723 K. The wettability and the adhesion are significantly enhanced when a small amount of Al is added to Si. In turn, the effect is less pronounced when Si is added to Al. Based on the Gibbs adsorption isotherm equation and a statistic thermodynamic model, the adsorptions of Si and Al at the liquid surface and the solid-liquid interface were determined, and the experimental results were explained by the fact that Si is a surface tensioactive element while Al is an interface tensioactive element in the Al-Si/(01 " 1 12) -Al 2 O 3 system.

Surface Orientation and Wetting Phenomena in Si/α‐Alumina System at 1723 K

“…Note that the wettability of the R‐face alumina is substantially improved by the addition of Al to Si, and it is quite close to that of the surface by pure Si. A recent more comprehensive study 21 demonstrates that in the Si–(Al)/(R)α‐Al 2 O 3 system, Al strongly tends to adsorb at the solid–liquid interface, which significantly reduces its interfacial free energy and thus promotes the wetting. Therefore, it is reasonable to infer that the Al termination and the surface structural reconstruction induced Al enrichment at the surface, which is similar to a situation of Al adsorption with Γ Al =14 nm −2 , 16,22 where Γ Al denotes an excess amount of Al at the surface per unit area, plays the dominant role in determining its much better wettability by pure molten Si than that of the oxygen‐terminated R and A faces.…”

“…15 Moreover, the reconstructed C-ð ffiffiffiffiffi 31 p  ffiffiffiffiffi 31 p ÞR AE 9 surface, which is extremely stable upon heating in vacuum to a high temperature (about 1473 K), is likely to be a surface oxygendeficient structure compared with the unreconstructed C-(1  1) surface. 11,15 Recently, the structure of this reconstruction surface has been specifically studied by both experimental techniques [16][17][18] and theoretical methods. 19,20 For instance, Gautier et al 16 measured the intensities of the oxygen (1s) and aluminum (2p) photoelectron lines on a C-(1  1) surface and a C-ð ffiffiffiffiffi 31 p  ffiffiffiffiffi 31 p ÞR AE 9 surface using a combined low-energy electron diffraction (LEED)-grazing incidence X-ray scattering (GIXS) approach, and found that the surface oxygen to aluminum ratio decreased by 1575% for the reconstructed C-ð ffiffiffiffiffi 31 p  ffiffiffiffiffi 31 p ÞR AE 9 surface.…”

On Simultaneous Sintering and Joining by Electric Current Activated Interfacial Eutectic Melting of Al–Si for Electronic Packaging Applications

“…34 The surface properties of Al−Si melt are a complex phenomenon, and contradicting reports on segregation of elements from the melt have been found in the literature. Shen et al 35 reported segregation of Si atoms to the surface of liquid Al−Si alloy, whereas Kobatake et al 36 reported otherwise. Thus, it is important to understand the wettability of molten aluminum as well as molten silicon individually with the surfaces to be joined.…”

Microstructures and Mechanical Properties of ZrC Reinforced (Zr‐Ti)‐Al‐Ni‐Cu Glassy Composites by an In Situ Reaction

“…XRD patterns of the single-phase amorphous Zr 55 Cu 30 Al 10 Ni 5 alloy and the glassy composites containing5,9,13,19, and 25 vol% of ZrC.…”

“…In fact, they are of significant importance in the fabrication of metal matrix composites when using a liquid casting route. [19,20] In order to maximize interfacial bond strength in the BMGMCs, it is necessary to promote wetting and control chemical reaction. Enhanced wetting usually induces higher strength of the interface, which is beneficial for the mechanical properties of the composite.…”