Papers by Author: Wei Peng

Abstract: A method of fabricating convex plate-shaped micro electrode was proposed based on the electrochemical etching principle. The square sectional electrodes were prepared in advanced using wire-EDM, The micro cylindrical electrode was fabricated firstly by using the eletrochechemical etching method. Then the top end was insulated to protect it from etching. Then the convex plate-shaped micro electrode was obtained in subsequent etching. Comparative experiments in drilling micro-hole in stainless steel with the thickness of 1mm were done by using the cylindrical and convex plate-shaped micro electrode. Results shows that the better locality, smaller side-gap and hole taper could be obtain by using convex plate-shaped micro electrode.

Abstract: Heat generated during wire saw slicing can cause silicon temperature raise and make silicon wafer warpage, especially for larger silicon wafers. In order to study the wire saw effect on silicon temperature during slicing process, three kinds of wire saw, mainly semi-fixed abrasive wire saw and traditional wire saw, are applied for slicing silicon ingot. In this paper, the thermocouple is used to measure the temperature of the silicon during wire saw slicing. The experiment results show that the temperature of the silicon increases along with the wire saw working direction and reaches maximum value near the outlet position of silicon. The temperature of the silicon sliced by semi-fixed abrasive wire saw is lower than that sliced by traditional wire saw.

Abstract: The complex of β-cyclodextrin (β-CD) and RC2540 dialkyl pentasulfide was synthesized and characterised by means of fourier transform infrared spectroscopy (FTIR), thermo-gravimetric analysis (TG) and scanning electron microscope (SEM). Then the friction and wear behavior of RC2540, β-CD and complex were studied by four-ball test using the mixture of PEG-600 and water as base fluid, and finally the lubrication mechanism of β-CD and the complex were analyzed using energy-dispersive X-ray spectroscopy (EDS). The experimental results revealed that the complex had formed well and had better antifriction and anti-wear property than β-CD. RC2540 in complex was released and the extreme pressure film was formed on the friction interface in the friction process. The β-CD molecules in complex were cracked into fragments, and the fragments with hydroxyl also formed lubricating film and fragments with no hydroxyl were mainly carbonized. The lubricating film of the complex had a better tribological performace due to the cooperation of the lubricating film of β-CD and extreme pressure film of RC2540.

Abstract: Micro-electrode preparation is the key technology in micro-machining of micro- mechanics and micro-parts. In this research, the machining method of micro-pin using micro-electrochemical machining (micro-ECM) was proposed. The principle of micro-pin fabrication is introduced and the studies are focused on the effects of varies parameters on the shape of the micro-pin. The theoretic model between the shape of micro-pin and the parameters including power, voltage, duty ratio of pulse power, immerge depth of electrode is built up and then verified by experimentations. Experimental results denote that the micro-electrode with desirable shape and size could be prepared by controlling applied parameters. When the immersing depth is deeper, the pulse power, low voltage and duty ratio is proper selected. On the contrary, the DC power or pulse power with higher voltage and duty ratio should be applied. Finally, micro-pin with diameter of 5μm and 60μm long was fabricated when the DC power of 1.8V voltage and immersing depth of 1mm is applied.

Abstract: China's English education has acted as a huge and persistent system. But still it can not solve the problem that graduates can not use English well in their professions. In this paper, based on the project of bilingual teaching reform of "Advanced Manufacturing Technology", it is presented that the bilingual teaching for senior in university should act as a final ring in the foreign language education chain in China. In this final ring, both the teaching philosophy that English is only a kind of tool and the teaching strategy of using English are two crucial factors. The teaching result shows that the bilingual teaching played a multiplier effect in achieving the ultimate goal of English education.

Abstract: This article discusses the influence factors of bilingual teaching effect by bilingual teaching practice of the Advanced Manufacturing Technology, and proposes solutions. Practice shows that the reform of teaching idea is the prerequisite for the effective bilingual teaching, and PBL teaching model is the effect ways to improve the effects of bilingual teaching.

Abstract: A novel technology is studied in this paper to make photosensitive resin grinding wheel based on layered manufacturing technology. The bond strength among resin layers is analyzed. An effective measure is proposed to improve the bond strength among resin layers of the grinding wheel. We add magnetic abrasive particles into the liquid resin to get rough surface and increase contact area by action of magnetic force. Some experiments are curried out for testing shear strength of resin with magnetic abrasive under different conditions. Results show that this method had a significant effect in improving the bond strength among layers of new grinding wheel.

Abstract: Fixed-abrasive diamond wire saw is widely used for slicing semiconductor materials. In this paper, a novel manufacturing method is studied by using polyethylene wire to replace the traditional metallic core wire. A new coating device of ultraviolet-curing for rapidly making diamond wire saw is developed. In terms of tensile strength experiments’ results, a high strength polyethylene multi-strand wire is finally selected as the core wire of the fixed-abrasive wire saws. Experimental results show that the high tensile strength of polyethylene multi-strand wire can satisfy the technical requirements of fixed-abrasive wire saws.

Abstract: In this paper, the adsorption characteristics of cationic polyelectrolyte PDADMAC on BGF particles and Zeta potential of BGF particles have been investigated. A new type of composite abrasive slurry was obtained with cationic polyelectrolyte modified BGF particles and its polishing performance was studied. Experimental results showed that the Zeta potential of the modified BGF particles was changed from negative to positive and the maximum value (+35mv) was obtained when the adsorption saturation was achieved, and the adsorption capacity of SiO₂ abrasives on BGF particles was improved significantly as well. The material removal rate was 469nm/min with the modified BGF/ SiO₂ composite abrasives slurry containing 5% SiO₂ and 3% modified BGF particles, increasing by 47% and 89% than those of the unmodified BGF/SiO2 composite abrasives slurry (319nm/min) and the single silica abrasives slurry (248nm/min), respectively.

Abstract: In this study the prediction of the erosion profiles during ECM of the spiral hole was presented. By assumptions, the major points were simplified into one-dimensional problems. The theoretical and computational model was built to illustrate the profile movement as the time elapses. The analysis was based on the law of electrolysis and the software MATLAB was used. Verifications were done through experiments and the deviation was 7.5% between theoretical and experimental result. On the basis of the prediction of the erosion profile, the applied parameters could be estimated.