Micro-arc oxidation (MAO) coating was prepared in different electrolyte compositions on 6063 alloy and its characterizations were detected by X-ray diffractometer (XRD), scanning electric microscope (SEM), energy dispersive X-ray spectrometer (EDX) and Vickers hardness tester. Friction and wear behaviors of the coatings were tested without lubrication and the abrasion loss was measured after the friction test. The results showed that the MAO coatings, presenting rough and porous surface and high hardness, mainly consisted of α-Al2O3 and γ-Al2O3 phases. The composition of electrolytic solution had great influence on the coating morphology and its mechanical performance. Compared with the coating prepared in silicate and borate solutions, the coating prepared in aluminate solution had not only denser and smoother surface but also higher micro-hardness value and better abrasion resistance.

Effects of different preparation parameters on the structural and mechanical properties of micro-arc oxidation coatings prepared in silicate electrolyte on 6063 alloy were investigated. The results show that the growth rate of ceramic coating increases with increasing current density and electrolyte concentration. The prepared coating had denser and smoother surface with few defects, higher micro-hardness values and better wear resistance when the current density was increased to 20A/dm2. The measurement properties were all up to their optimum values when the electrolyte concentration was in the range of 9-12g/l and oxidation time was 60min, respectively.

In the automatic assembly of locks system the pins’ selection depends on depth of key’s groove. Although the kinds of groove’s depth are fixed, the arrangements are random and they can’t be unpredictable. The difference in depth of key’s groove is very small, so it can’t be judged by eyes accurately. To solve the problem that the pins assembly is tried frequently, the depth of keys’ groove can be measured accurately by the machine vision. So the problem of the serious influence production efficiency is solved successfully. This kind lock is widely used and machine’s cost is very low by allocation. The experiments show that this method fully met the locks automatic assembly system requirements from the assembly precision, real time performance and robustness and other aspects, solving the problems encountered in the lock assembly.

In metal forming process analysis, the accuracy loss is inevitable for complex boundary shape, un-uniformly distributed points and high velocity gradient distribution in analysis domain. In order to improve simulation accuracy, an h-adaptive procedure for the background required rigid (visco) plastic meshless Galerkin method is developed. A mixed posteriori error indicator is presented, which consists of a cell energy rate integration error estimator and a cell energy rate approximation error estimator to indicate the integration error and the approximation error, respectively. The corresponding local refinement strategies are developed, and the adaptive refining procedure is given. The adaptive procedure is applied only once in each time step simulation for the consideration of computational efficiency. A bulk forming process with severe metal deformation is analyzed. In comparison with the results obtained by using software Deform-2D, the effectiveness of the method developed in this paper is demonstrated.

With the rapid development of China's transportation industry, the scale of road and bridge works is increasing, and the construction quality of road and bridge has become an important work content of the transportation industry. The quality of the road bridge project is in addition to the material, the quality of construction personnel and construction management, but also by the construction technology interference. This paper analyzes the common technical problems in the construction of road and bridge, and puts forward the corresponding measures to ensure the quality of road and bridge construction.