Adsorption-induced strength lowering

The decrease in the surface energy of a solid occurs not only upon the adsorption of vapor, but also (to the same or greater extent) during capillary condensation with a continuous transition to a direct contact between the solid phase and the bulk volume of liquid. Consequently, the effects of strength decrease due to the contact of solids with a liquid phase are also included in the generalized concept of adsorption-induced strength lowering. 

Up to this point, we have been talking about the lowering of the interfacial energy, o i, of a solid metal at the interface with a liquid phase. In the case when the amount of fusible component does not exceed its solubility in the solid phase, there is no film of liquid phase present at the surface. Under these conditions (thermodynamic equilibrium), only the adsorption layer may form at the solid surface. Such conditions favor an adsorption-induced strength lowering in the narrowest sense of this term. It was shown by Frumkin that for the case when there is a finite contact angle, there is... 

Disperse porous materials are of interest in the analysis of adsorption-induced strength lowering mechanisms, including porous bodies with ionic structure. Convenient model objects for studying... 

The adsorption-induced strength lowering is even more pronounced in disperse structures with point-Uke atomic contacts that are formed upon the removal of a liquid phase from the adsorption layers present in the coagulation structures (see Chapters 2 and 3). This is the main cause for the poor water resistance in certain grounds, the formation of the so-called quick grounds. 

Influence of the Real (Defect) Structure on the Adsorption-Induced Strength Lowering... 

The degree of the manifestation of adsorption-induced strength lowering depends on many factors and may cover a very broad range. This is a reason for the various apparent contradictions found in the literature regarding either the influence or noninfluence of the media in various cases. 

One example of the utilization of adsorption-induced strength lowering in these processes is the use of small amounts of fusible surface-active metals in the treatment of hardened steels and solid alloys. The powder of a fusible metal is introduced into the polymeric binder of grinding wheels along with the diamond powder (Figure 7.50). Due to the increase in temperature in the course of the grinding, the microamounts of active metal are melted and lower the strength of hard metals and... 

Pertsov, N. V., Sinevich, E. A., and E. D. Shchukin. 1968. Adsorption-induced strength lowering of molecular crystals. Doklady AN SSSR. 179 633. 

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