Moisture deformation of concrete subjected to alkaline corrosion. Experimental results

The authors present the results of the study of concrete core samples extracted from the concrete coating of the airfield that was exposed to alkaline corrosion. It is shown that by the nature of the volumetric deformation kinetics, concrete samples can be classified into three groups: samples mainly subjected to swelling; samples mainly subjected to shrinkage; samples that have a marked technogenic metasomatosis. The experimetal investigation results have confirmed the theoretical conclusions drawn on the base of the technogenic metasomatosis model. There have been revealed the facts of latent technogenic metasomatosis, confirming its prevalence in concrete products. The study of volumetric deformation of samples during their exposure to various media provides additional information for assessing the material`s durability: the ascertained deformation of the samples is the evidence of the exchange processes that will reduce the operation properties of the material with an intensity increasing over time.

AFM Measurements of the Deformation Kinetics of Silica Oxide Dots Deposited on a Sequentially Nitrided Stainless Steel

In this paper, we present the results of plasma nitriding treatments on austenitic stainless steel substrates previously coated with a patterned silicon oxide layer. For this purpose, masks were made by PECVD for the deposition of a silicon oxide layer on polished austenitic AISI 316L samples. For the final nitriding treatment, we used a multi-dipolar plasma providing independent substrate polarization. The interactions between expanded austenite and fixed silicon oxide mask in different shapes (circular and square dots) are observed by atomic force microscopy (AFM) on the same area before and after the nitriding treatment. After this thermochemical treatment, we obtain strong distortions of the dots, in particular at the edges of the larger size dots. The role of elastic deformation, due to the expanded austenitic phase formed by the diffusion of nitrogen under the mask is of primary importance.

Electrochemomechanics of lithium dendrite growth

The work demonstrates the electrochemomechanical driving forces, equilibrium, and large deformation kinetics for lithium dendrite growth.