Showing papers on "Sessile drop technique published in 1968"
TL;DR: In this paper, the wettability of sapphire single crystals by liquid copper which contained oxygen added as cupric oxide was investigated using the sessile drop technique in vacuum at 1230°C.
Abstract: The wettability of sapphire single crystals by liquid copper which contained oxygen added as cupric oxide was investigated using the sessile drop technique in vacuum at 1230°C. Additions of cupric oxide to copper, varying from 1 to 72% of copper weight, resulted in rapid chemical reaction at the solid-liquid interface with a significant reduction of the contact angle, the final value being dependent on the oxygen in the system. In all cases the interfacial product was CuAlO2. A linear relation between the fourth power of the basal radius of the molten drop and the amount of oxygen present was observed. The initial stage of the reaction could be explained by the formation of a Cu2O layer at the interface, followed by reaction between Cu2O and Al2O3 to form CuAlO2.
79 citations
TL;DR: In this paper, a variational method is used to minimize the total energy of the drop and the resulting expressions for the drop shape are evaluated numerically, making more direct use of accurately measurable drop width than do the classical treatments based on the analysis of Bashforth and Adams.
Abstract: A new analysis is presented of the shape of a liquid drop under the influence of gravity and surface tension. A variational method is used to minimize the total energy of the drop and the resulting expressions for the drop shape are evaluated numerically. The new treatment makes more direct use of the accurately measurable drop width than do the classical treatments based on the analysis of Bashforth and Adams.
20 citations
TL;DR: In this paper, a perturbation solution is obtained to the differential equation resulting from the application of Newton's second law to the surface of a sessile drop on a smooth horizontal surface.
17 citations
TL;DR: In this article, the liquid surface tension of copper was determined to be 1212 dyn/cm at its melting point, and that of Al2O3 to be 600 dyn/m at their melting point.
Abstract: Liquid surface tension measurements using the sessile drop, pendant drop and drop weight methods are discussed. These measurements refer to high temperature materials which melt at temperatures greater than 2000° C. The liquid surface tension of copper was determined to be 1212 dyn/cm at its melting point, and that of Al2O3 to be 600 dyn/cm at its melting point. Discussion is presented giving preference to the drop weight method.
15 citations
6 citations
TL;DR: In this article, the authors performed wetting tests on refractory metal-ceramic combinations selected on the basis of previous compatibility studies and found that they have desirable wetting and solubility characteristics for making cermets.
Abstract: Wetting tests were performed with refractory metal-ceramic combinations selected on the basis of previous compatibility studies. Sessile drop contact angles between liquid Cr, V, Pt, Rh, Mo, and Mo-Re alloy and solid ThO2, HfO2, ZrO2, HfC, TaC, and ZrC were measured at temperatures up to 2800° C in helium. Little wetting occurred between these metals and the refractory oxides, but Mo and the Mo-Re alloy did wet the refractory carbides. Microscopic examination of the metal-ceramic interfaces showed that HfC-Mo-40 wt% Re and ZrC-Mo-40 wt% Re had highly desirable wetting and solubility characteristics for making cermets. Specimens were fabricated from these two systems with 25 and 50 vol% metal by cold-pressing and sintering and by hot-pressing. The microstructures of these cermets consisted of small, uniformly dispersed carbide particles in Mo-Re matrixes. The hardnesses and transverse rupture strengths of these cermets indicate that they have considerable promise for high-temperature applications.
4 citations