The tensile and compressive behaviors of 316L stainless steel at room temperature were compared. The differences between the stress–strain responses during tension and compression were explained by the different evolutions of the texture, defect structure, and phase composition. It was found that up to true strain of ~ 25 pct the flow stress during tension was only slightly higher (by ~ 40 MPa) than that during compression, which can be explained by the different textures of the two types of specimens. On the other hand, between the strains of 25 and 50 pct, the strain hardening for tension was much higher, which resulted in a ~ 200 MPa larger flow stress in the tensile-tested specimen at 50 pct strain. It was revealed that the higher flow stress in tension was caused by the harder texture, the higher dislocation density, and the larger fraction of martensite phase.
24 November 2020 in Advanced Engineering Materials
In the article, number 2000351, the group of Jeno Gubicza and co‐workers revealed that the Ni foam fabricated via freeze casting in combination with thermal oxidation is a promising canditate as an anode material in Li ion batteries. The as‐processed Ni foam anode demonstrated good cycling and rate performance during charging/discharging process.
The paper presents the microstructure and corrosion behavior of an AlTiNiCuAgSn new equiatomic multicomponent alloy. The alloy was obtained using the vacuum arc remelting (VAR) technique in MRF-ABJ900 equipment. The microstructural analysis was performed by optical and scanning electron microscopy (SEM microscope, SEM-EDS) and the phase transformations were highlighted by dilatometric analysis and differential thermal analysis (DTA). The results show that the as-cast alloy microstructure is three-phase, with an average microhardness of 487 HV0.1/15. The obtained alloy could be included in the group of compositionally complex alloys (CCA). The corrosion resistance was studied using the potentiodynamic method in saline solution with 3.5% NaCl. Considering the high corrosion resistance, the obtained alloy can be used for surface coating applications.
5 September 2022 in Materials Science and Engineering: A
In this work, a comprehensive investigation of amorphous and crystalline modification of identical electrode active material as a thin-film electrode for a future all-solid-state Li-ion battery application is presented and discussed. Using the proposed micro-battery system, we aim to unravel the effect of the crystallinity of the positive electrode material on the intrinsic durability of all-solid-state thin-film Li-ion batteries during prolonged electrochemical cycling. We demonstrate the preparation, structural-, nanomechanical and electrochemical characteristics of molybdenum (VI) oxide (MoO3) thin-film cathodes based on their different crystallinity. The nanomechanical properties of the electrode layers were determined using nanoindentation along with acoustic emission studies. Based on the electrochemical test results, as-prepared thin films that did not go under any heat treatment showed the best performance and stability throughout cycling around 50 μAh initial capacity when cycled at C/2. This suits well their nanomechanical properties, which showed the highest hardness but also the highest flexibility in comparison with the heat-treated layers with lower hardness, high brittleness, and numerous cracks upon mechanical loads. According to our results, we state that amorphous-type electrode materials are more durable against electro-chemo-mechanical-aging related battery performance loss in all-solid-state Li-ion batteries compared to their crystalline counterparts.