Environmental effect on sclerometric brittleness of ionic crystals

Surface Modification and Contact Interaction of Particles

“…[54,70,71] Catalysis assisted rupture of surface bonds may result also in creating new adatoms and, correspondingly, in accelerating the adatoms diffusion and particle sintering, [72] i.e., in increasing the strength, or achieving the same interparticle contacts and strength at lower sintering temperatures (catalysis enhanced sintering-CES). [75,76] To complete this consideration of the influence of adsorption modification of the surface on mechanical behavior, we include here also some data on the manifestation of such influences in compact solids. [73,74] Surface modification effects can be determined by the influence of medium and adsorption on the damageability of a solid surface, particularly, on the deformation and fracture processes in the thinnest subsurface layers.…”

“…15 and 16. [75,76] (4). This phenomenon, the adsorption caused decrease in strength (ADS), or the Rehbinder effect was discovered by Rehbinder in 1928: he observed facilitation of some crystal (quartz, fluorite) cleavage in surfactant solutions, and explained the nature of this effect as a result of a decrease in the surface energy of solid phase, i.e., in the work of new surfaces formation during fracture.…”

“…[75,76] To complete this consideration of the influence of adsorption modification of the surface on mechanical behavior, we include here also some data on the manifestation of such influences in compact solids. [75,76] [12] In the 1950s investigations were carried out on the embrittlement and strength lowering (sometimes-dramatic, of the order of magnitude) of the single-and polycrystalline metals under the influence of metal melts.…”

Microscratching in an electrochemical cell. Effect of gallium on the surface deformation in aluminum

“…The tests become particularly informative for small loads on the indenter, as in micro-and ultramicrosclerometry developed by the authors in [13][14][15][16][17][18]: these methods allow one to observe the appearance of the very first dislocations along the path of the indenter, i.e., elementary events of damage, and the transition from the elastic behavior of the material to its plastic behavior in the contact zone and to the brittle response of the material depending on the pH value, admixtures of surfactants in aqueous solutions, and other characteristics of the medium. The tests become particularly informative for small loads on the indenter, as in micro-and ultramicrosclerometry developed by the authors in [13][14][15][16][17][18]: these methods allow one to observe the appearance of the very first dislocations along the path of the indenter, i.e., elementary events of damage, and the transition from the elastic behavior of the material to its plastic behavior in the contact zone and to the brittle response of the material depending on the pH value, admixtures of surfactants in aqueous solutions, and other characteristics of the medium.…”