Titanium-Aluminium Oxide Coating on Aluminized Steel

In this study, a plasma electrolytic oxidation (PEO) process was used to form titanium-aluminium oxide coating on aluminized steel. The present work was mainly to study the effects of treatment time of PEO process on properties of the titanium coating. A potentiodynamic polarization corrosion test was employed to investigate the corrosion resistance of the coating. The friction coefficient and wear resistance of the coating were studied by using pin-on-disc test. The thermal transfer behaviours of uncoated and PEO-coated aluminized steels were also studied. It could be seen that treatment time of PEO process significantly influenced the properties of the titanium oxide coating. Samples with a longer treatment time had a better performance for corrosion and wear protection. This paper demonstrated different treatment time could alter the surface behaviour of the coating material

Wear mechanism evolution on brake discs for reduced wear and particulate emissions

Brake disc wear contributes heavily to particulate matter as non-exhaust emission in the transportation sector. To tackle this issue, research on this topic has so far been directed at obtaining a hard and dense disc surface to reduce abrasive wear. The present research manipulates the disc surface morphology so that an adhesive transfer layer can be formed during sliding to protect the disc from wear. The designed interlocking surface was prepared using plasma electrolytic aluminating (PEA) process. A non asbestos organic (NAO) brake pad was used for tribotests. The results showed that the PEA-treated brake disc exhibited negligible wear because of the thin protective layer generated by the pad material transfer onto the PEA-treated cast iron. The dimple-like surface, produced through the PEA process, enhanced the bonding of the transfer layer due to mechanical interlocking. The coated surface increased the coefficient of friction of the disc to some extent. The surface also resulted in a reduced wear rate of the brake pad, highlighting the potential for the PEA process to enable reduced wear debris and thus non-exhaust emission through an altered wear mechanism in future brake disc applications.</p

Embedded Multi-label Feature Selection via Orthogonal Regression

In the last decade, embedded multi-label feature selection methods, incorporating the search for feature subsets into model optimization, have attracted considerable attention in accurately evaluating the importance of features in multi-label classification tasks. Nevertheless, the state-of-the-art embedded multi-label feature selection algorithms based on least square regression usually cannot preserve sufficient discriminative information in multi-label data. To tackle the aforementioned challenge, a novel embedded multi-label feature selection method, termed global redundancy and relevance optimization in orthogonal regression (GRROOR), is proposed to facilitate the multi-label feature selection. The method employs orthogonal regression with feature weighting to retain sufficient statistical and structural information related to local label correlations of the multi-label data in the feature learning process. Additionally, both global feature redundancy and global label relevancy information have been considered in the orthogonal regression model, which could contribute to the search for discriminative and non-redundant feature subsets in the multi-label data. The cost function of GRROOR is an unbalanced orthogonal Procrustes problem on the Stiefel manifold. A simple yet effective scheme is utilized to obtain an optimal solution. Extensive experimental results on ten multi-label data sets demonstrate the effectiveness of GRROOR

Effects of Surface Coating Preparation and Sliding Modes on Titanium Oxide Coated Titanium Alloy for Aerospace Applications

This paper investigates the mechanical response of a coated Ti-6Al-4V alloy surface under different sliding contact stress conditions. The surface was coated with an oxide ceramic material created through the use of a recently developed technique known as plasma electrolytic oxidation (PEO). During the PEO procedure, a composition of silicate and phosphate was used as the electrolyte. In order to evaluate the coating, pin-on-disk (POD) tribology tests and cyclic inclined sliding tests were used under dry room conditions. Furthermore, scanning electron microscopy (SEM) and energy dispersive spectroscopy (EDS) were utilized to examine the morphology and composition of the coating surfaces. The results of the POD tests revealed that the PEO coating could have a low coefficient of friction and suggested that high silicon concentrations in the PEO coatings take away oxygen from stoichiometric Ti oxides to create lubricating oxides. In addition, cyclic inclined sliding tests showed that smaller pores on the surface of the coating could permit a higher coating cohesive strength and allow the coated Ti alloy surface to perform better under high inclined sliding forces

Numerical analysis of geometrical nonlinear aeroelasticity with CFD/CSD method

A nonlinear static aeroelastic methodology based on the coupled CFD/CSD approach has been developed to study the geometrical nonlinear aeroelastic behaviors of high-aspect-ratio or multi-material flexible aerial vehicles under aerodynamic loads. The Reynolds-averaged Navier-Stokes solver combined with the three-dimensional finite-element nonlinear solver is used to perform the fluid-structure coupling simulation. The interpolation technique for data transfer between the aerodynamic and structural modules employs radial basis function algorithm as well as dynamic mesh deformation. A high-aspect-ratio structure with multi-material is modeled by the finite element method to investigate the effects of geometrical non-linearity on the aeroelastic behavior. Numerical simulations of the linear and nonlinear static aeroelasticity were conducted at transonic regime with different angles of attack. By comparing the aeroelastic behaviors of linear and nonlinear structure, it shows that geometrical nonlinearity plays an important role for flexible high-aspect-ratiowings undergoing the large static aeroelastic deformation and should be taken into account in aeroelastic analysis for such structures

One-Step Fast-Synthesized Foamlike Amorphous Co(OH)₂ Flexible Film on Ti Foil by Plasma-Assisted Electrolytic Deposition as a Binder-Free Anode of a High-Capacity Lithium-Ion Battery

This research prepared an amorphous Co­(OH)₂ flexible film on Ti foil using plasma-assisted electrolytic deposition within 3.5 min. Amorphous Co­(OH)₂ structure was determined by X-ray diffraction and X-ray photoelectron spectroscopy. Its areal capacity testing as the binder and adhesive-free anode of a lithium-ion battery shows that the cycling capacity can reach 2000 μAh/cm² and remain at 930 μAh/cm² after 50 charge–discharge cycles, which benefits from the emerging Co­(OH)₂ active material and amorphous foamlike structure. The research introduced a new method to synthesize amorphous Co­(OH)₂ as the anode in a fast-manufactured low-cost lithium-ion battery