Preparation of HA-MAO coatings on ß-type alloys and its corrosion resistance in high glucose environments.

Aim to provide practical clinical guidance for the treatment of implants in diabetic patients, this study investigated the corrosion mechanism of bionic coatings containing different Ca/P ratios in diabetic environments. The bionic coatings were prepared in ß-titanium alloys using micro-arc oxidation (MAO) technology and evaluated for corrosion mechanism, biocompatibility, and safety by cytotoxicity, electrochemical corrosion, and coating bonding force experiments. Ca and P from the electrolyte were integrated into the coating during MAO discharge process to form hydroxyapatite. The coating Ca/P ratio initially increased and then decreased with the electrolyte Ca/P ratio. In vitro cellular experiments demonstrated that increasing the porosity of HA-containing coatings would be beneficial to the growth of cells adhering to their surfaces. Corrosion tests revealed that the corrosion tendency of the coating at higher sugar content was more severe, and a proper elevation of the Ca/P ratio was better for the corrosion resistance of the coating. The bonding analysis of the coatings before and after corrosion showed that an increase in the Ca/P ratio would improve the bonding of the MAO coatings in higher glucose content environments, thus improving the safety of the implants in diabetic patients.

Evolution of Microstructure and Mechanical Properties of Ti-6Al-4V Alloy under Heat Treatment and Multi-Axial Forging.

The mechanical properties of various Ti-6Al-4V alloys are influenced by their respective microstructures. This study generated an ultrafine-grain (UFG) Ti-6Al-4V alloy featuring bimodal grain distribution characteristics achieved through initial heat treatment, multi-axial forging (MF), and annealing. The study also extensively examined the evolution process of the alloy's microstructure. By subjecting the materials to heat treatments at 900 °C with air cooling and 950 °C with air cooling, both materials were found to be consisted of primary α (αp) and transformed ß (αs+ß) regions with different proportions. Following MF, the sample treated at 900 °C displays a microstructure featuring UFGs of α+ß surrounding larger micron-sized αp grains. On the other hand, the sample treated at 950 °C displays a microstructure distinguished by twisted αs lamellar and fragmented ß grains surrounding larger micron-sized αp grains. Following annealing, no significant grain growth was observed in the sample. The geometrically necessary dislocations (GNDs) within the UFGs were eliminated, though some GNDs persisted within the αp grains. The samples undergoing the 900 °C heat treatment, MF, and subsequent annealing exhibited elevated strength (1280 MPa) and total elongation (10.7%). This investigation introduces a novel method for designing the microstructure of the Ti-6Al-4V alloy to achieve superior performance.

Evaluation of surface texture of dried Hami Jujube using optimized support vector machine based on visual features fusion.

The surface texture of dried jujube fruits is a significant quality grading criterion. This paper introduced a novel visual feature fusion based on connected region density, texture features, and color features. The single-scale Two-Dimensional Discrete Wavelet Transform was used to perform single-scale decomposition and reconstruction of dried Hami jujube image before visual features extraction. The connected region density was extracted by the two different algorithms, whereas the texture features were extracted by Gray Level Co-occurrence Matrix and the color features were extracted by image processing algorithms. Based on selected features which obtained by correlation analysis of visual features, the accuracy rate of the optimized Support Vector Machine classification model was 96.67%. In comparing with Extreme Learning Machine classification model and other fusion methods, the optimized Support Vector Machine based on selected visual features fusion was better.