Abstract: The electrochemical behavior of anodic dissolution of copper electrode was investigated in non-cyanide alkaline electrolyte containing 1-hydroxyethylene-1, 1-diphosphonic acid (HEDPA) as a complexing agent. Electrochemical behavior of copper electrode was studied by cyclic voltammetry. X-ray photoelectron spectroscopy was used to study morphologies of copper electrode after dissolution under different potentials. The results showed that in cyclic voltammetry curve of the 1-hydroxyethylene-1,1-diphosphonic Acid(HEDPA) baths, the first peak of copper anode was diffusion-controlled, associated with the formation of Cu2O. The second oxidation peak came from generating CuO and the third peak was the formation of CuO/Cu(OH)2 compound.
Abstract: An algorithm is proposed on the real-time generation of cutter location curves for pen-cutting of sculptured surface. First of all, the parameter of driving curves can be calculated based on Taylor series expansion according the kinematics and geometric relation between cutter contact loci and driving curves. Cutter contact points on the surface can be achieved. Then cubic B-spline curves are used to fit the ideal cutter location curves. Examples and analysis results have indicated that the algorithm can realize the regeneration of tool path, simplifying the NC programming and improving the precision of sculptured surface machining.
Abstract: The aim of this paper is to address the accelerated fatigue life under rolling contact condition of coatings. The NiCr-Cr3C2 ceramic-metal and Ni-Al alloy were deposited on steel substrate as topcoating and undercoating using supersonic plasma spraying technique, respectively. Accelerated fatigue life tests were conducted using a ball-on-disc tester. The life of coatings was evaluated by Weibull distribution plots and the accelerated fatigue life model was established. The results showed that the coupling relationship between the load and failure life of coatings could be obtained using this model. Accelerated life test for fatigue of coatings could improve the experimental efficiency.
Abstract: In the rolling process of Magnesium Alloy, different mixtures of organic and inorganic compounds are used to lower the friction. Such coolants and lubricants may age or deteriorate during use. This paper describes a method for evaluating oxidation stability performance of lubricants by TG–DSC analyzer. The influence of oxidation on the volatility of lubricants and the tendency of the formation has been studied by comparing the TG curves and DSC curve of lubricants obtained under 298K to 798K atmosphere. The results show that this method is potentially useful for lubricants selection and quality control and for studying influence of base lubricants composition on oxidation performance.
Abstract: In this paper, an adaptive and iterative neighborhood search strategy is proposed to precisely evaluate the flatness error. Firstly, an initial datum plane produced by least squares method (LSM) is calculated. And then, a group of candidate planes are generated by adjusting the direction angles of the LSM datum plane. The flatness errors conform to the minimum zone condition for each candidate datum plane that can be worked out. The one with minimum flatness error will be selected as the new start plane for the next search. The new search area is the zone between the new and old datum planes, with which the new search step is computed until the terminal condition is met. Numerical examples are given to validate the proposed strategy. The results show that the proposed method could get the precise value of the flatness error from the data of coordinate measuring machines and other equipment.
Abstract: A nanostructured surface layer was produced on an 20CrMo steel plate by means of ultrasonic shot peening (USSP) treatment. Plasma nitriding of the treated and un-treated sample were investigated by using structure analysis (X-ray diffraction, optical microscopy, and transmission electron microscopy ) as well as hardness measurements. It was found that a nanostructured surface layer sample developed a compound layer twice as thick as that in a coarse-grained sample under the same plasma nitriding conditions (530 oC for 6 h). In addition, the USSP nitrided sample exhibited higher hardness and thicker hardened surface layer in comparison with coarse-grained nitrided sample.
Abstract: The aim of process mining is to identify and extract process patterns from data logs to reconstruct an overall process model. And the model’s structural complexity directly impacts readability and quality of the model. Immune systems have many characteristics such as uniqueness, autonomous, recognition of foreigners, distributed detection, and noise tolerance. This paper outlines an alternative approach to business process mining utilizing an artificial immune systems (AIS) technique, and some main steps and operators were depicted.
Abstract: With the rapid development of China's electric power market today, the national provincial electric power companies, which are under the background of the principal-agent framework management, have become the main development pillars of the national electric power companies. These companies are responsible for many important businesses such as electric power market exploitation, power grid construction, electric power operation mode transformation, etc., and they are relatively independent management subject. How to evaluate the performance of provincial companies is always a focus point of the management of the national electric power company. The author tries to improve the C2R evaluation model of the DEA method and construct the super-efficient DEA evaluation model, in order to solve the problem that the sorting and selecting decision cannot be made when there are more than one effective decision unit, furthermore, to apply it to evaluate the operation efficiency of provincial companies and propose measures to improve business performance. The author hopes this can provide good ways of improving the reformation of electric power companies marketization in their reformation process.
Abstract: WS2 soft coated tools were deposited by medium-frequency magnetron sputtering, multi-arc ion plating and ion beam assisted deposition technique on the YT15 cemented carbide substrates. The influence of the deposition temperature on the coating properties has been studied. The coatings exhibited a dense and fine grained structure. WS2 coatings revealed a (002) preferred crystal orientation. WS2 soft coatings with deposition temperature of 200°C revealed a better crystallization of (002) preferred crystal orientation of Ⅱ texture than other three deposition temperatures. And the adhesive strength could get to 43.25N which was the largest. The thickness of WS2 coatings decreased firstly, then increased, and finally reduced with the increasement of deposition temperature. And the microhardness of the coatings increased firstly, then decreased, and finally increased with the increasement of deposition temperature.