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AA1235 aluminum alloys were twin roll cast into a 7.0 mm-thick billet and further rolled into a plate with 70% reduction, followed by annealing at 500 C for 8 h. Abnormal grains were found to be formed on the plate bottom surface. SEM, EBSD, and micro X-ray diffraction were used to analyze the mechanism underlying the abnormal growth of these grains. Results showed that the {100} >001001 AA1235 aluminum alloys were twin roll cast into a 7.0 mm-thick billet and further rolled into a plate with 70% reduction, followed by annealing at 500 C for 8 h. Abnormal grains were found to be formed on the plate bottom surface. SEM, EBSD, and micro X-ray diffraction were used to analyze the mechanism underlying the abnormal growth of these grains. Results showed that the {100} >001< texture was formed in the surrounding normal grains adjacent to the abnormal grain. The orientation angle between the abnormal grain and its adjacent normal grains was 45°. The {100} >001< texture formed during rolling and annealing accelerated abnormal grain growth. The partially dissolved Fe precipitates were heterogeneously distributed in the plate bottom heterogeneously, which also mainly explained abnormal grain growth. Show more Show less

The article demonstrates how acid-base properties of the surface of tin (II) oxide powders influence its photocatalytic activity in reaction of photodegradation of methylene blue. The experiment shows that the photocatalytic activity of the tin (II) oxide depends on the number and the strength of surface acid centers of the Lewis.

The time-transition curve of open circuit potential (Eoc) during the single zincating process of aluminium alloy 7075 (AA7075) was recorded. Then, a suitable single zincating duration was selected from the Eoc slope, in order to get the optimum zincating duration. The evolution of surface morphology and composition of AA7075 substrate at various single zincating durations were characterized by scanning electron microscopy (SEM) and energy dispers... The time-transition curve of open circuit potential (Eoc) during the single zincating process of aluminium alloy 7075 (AA7075) was recorded. Then, a suitable single zincating duration was selected from the Eoc slope, in order to get the optimum zincating duration. The evolution of surface morphology and composition of AA7075 substrate at various single zincating durations were characterized by scanning electron microscopy (SEM) and energy dispersive analysis of x- rays (EDX). The coating adhesions of single zincated samples produced at various durations were investigated using a scratch tester. SEM results showed that the substrates produced at a longer zincating duration were fully covered by a dense layer of zinc particles. The adhesion of the electrodeposited nickel on single zincated samples produced at longer zincating duration was higher than the conventional single zincating process. This morphology has contributed to the improvement of coating adhesion. Show more Show less

Adsorption behavior of four typical thiadiazole derivatives as corrosion inhibitors on copper surface both in vacuum and aqueous media, including 1,3,4-thiadiazole-2,5-mercapto (T-SH), (1,3,4-thiadiazole-2,5-diyl) bis (sulfanol) (T-OH), S,S'-(1,3,4-thiadiazole-2,5-diyl) bis (O-hydrogen carbonothioate) (T-COOH) and O,O'-dimethyl S,S'-(1,3,4-thiadiazole-2,5-diyl) bis (carbonothioate) (T-COOCH3), has been theoretically studied using quantum chemistr... Adsorption behavior of four typical thiadiazole derivatives as corrosion inhibitors on copper surface both in vacuum and aqueous media, including 1,3,4-thiadiazole-2,5-mercapto (T-SH), (1,3,4-thiadiazole-2,5-diyl) bis (sulfanol) (T-OH), S,S'-(1,3,4-thiadiazole-2,5-diyl) bis (O-hydrogen carbonothioate) (T-COOH) and O,O'-dimethyl S,S'-(1,3,4-thiadiazole-2,5-diyl) bis (carbonothioate) (T-COOCH3), has been theoretically studied using quantum chemistry calculations and molecular dynamics simulations method, and the corrosion inhibition mechanism has been analyzed. The present conclusions have been experimentally verified by corrosion test. Global activity indices indicate that T-OH has the highest reaction activity among the four molecules both in vacuum and aqueous environment. The reaction activity of T-SH is little weaker than T-OH. For the two other molecules, Fukui indices suggest that T-COOCH3 possesses five electrophilic attack centers, which enable multi-center adsorption of the molecule on metal surfaces and thus it has a preferable corrosion inhibition performance compared to T-COOH in vacuum. However, T-COOH has the higher reaction activity in aqueous. At the same time, molecular dynamics results show that T-COOCH3 is more stably adsorbed on copper with surface (110) crystallographic plane than T-COOH does both in vacuum and aqueous environment when the interaction of the inhibitor molecules with four layers of copper atoms is considered. The theoretical results show that the efficiency of the four inhibitors accorded well with experimental results. The study of the questions of oxidation and discoloration of copper surface is to be provided a new method. Show more Show less