Papers by Author: Zhe Jun Yuan

Abstract: The polyimide polishing film is a kind of soft polishing films with polyimide substrate and abrasive cement. It isn't replaced by other grinding tool because of its acid resistance, alkali resistance, water-resistance, oil resistance, heat-resistance et al. The paper focuses on ascertaining the minimal substrate thickness of polishing film, selecting molding method and molding technology. Applying the skim coating processes, and using a self-made, film making device, a lab-level, making process of polyimide polishing film is developed, and the polyimide polishing films are made in a lab. Then, study the polishing films form and analyze the molding performances with scanning electron microscope, and get an effect rule of the consistency of polyamides adhesive and abrasive to polyimide polishing films form and the appropriate consistency of polyamides adhesive finally.

Abstract: Cutting parameters play an essential role in the economics of machining. In this paper, particle swarm optimization (PSO), a novel optimization algorithm for cutting parameters optimization (CPO), was discussed comprehensively. First, the fundamental principle of PSO was introduced; then, the algorithm for PSO application in cutting parameters optimization was developed; thirdly, cutting experiments without and with optimized cutting parameters were conducted to demonstrate the effectiveness of optimization, respectively. The results show that the machining process was improved obviously.

Abstract: During the transferring process of the large die surfaces, there are extensive needs of die surface polishing. Since almost large die surfaces are free-form surfaces, currently, these are almost manually implemented. In order to overcome this barrier, base on design a floating polisher, this paper focuses on polishing rule of floating three polishing disks and the optimization of the associated polishing process parameters. In order to enhance the polisher performance, affecting factors of polishing process, including the rotation speed of polishing discs, normal acting force on polishing disc, loci of polishing disc movement, feeding rate of polishing disc, grit of abrasive particles, and inclined angle of the acting force on disc, are synchronized and analyzed versus roughness of polished surfaces. Then, using the parameter design plans and conducts tests regarding these affecting factors. Finally, the floating polishing process parameters are optimized based on the test results. These optimized results are used as operating guides for applications of the floating die polisher.

Abstract: Since almost large die surfaces are free-form surfaces, currently, these are almost manually implemented. In order to overcome this barrier, floating polishing is a feasible polishing technology. The contact pressure between grain and workpiece is a key problem of floating polishing technology. This paper focuses on contact pressure between grain and workpiece. At first, study the friction bound condition between grain and workpiece by ANSYS analysis software, then, compare with the analysis results of slip-line field theory and the test results of single grain. The results show the feasibility of the hypothesis of full friction condition. Finally, study the contact pressure between polishing disk and workpiece using the analysis results of single grain. The research achievements will be used for developing the floating polishing.

Abstract: In this paper, a two-dimensional (2D) fast tool servo driven by piezoelectric actuators for real time error compensation in taper turning is described. A 2D tool post is made with a new structure with three leaf springs for each axis and its mounting platform positions at a corner, which makes it convenient for mounting the cutter. A control technique, “Forecasting Compensatory Control” (FCC), is implemented to perform an on-line prediction of the machining errors encountered. The on-line cutting experimental results have verified that an improvement of about 40% was achieved for roundness error of the workpiece in the taper turning operation by using the developed control algorithm.

Abstract: During the transferring process of the large die surfaces, there are extensive needs of die surface polishing. Since almost large die surfaces are free-form surfaces, currently, these are almost manually implemented. In order to overcome this barrier, this paper focuses on a new technology of floating polishing, including a) the design of polisher body which has five degrees of freedom and realize the floating polishing while keep the polishing head being indifference equilibrium within the working range, b) normal force of polishing head on die surface analyses and experimental verification by using the slip line field method, and c) establishments of the interference boundaries between dies surface features and polishing head. The research achievements will be used for the development of a portable, state-of-the-art polishing machine and the optimization of the associated polishing process parameters in near future.

Abstract: Bonnet tool polishing is a novel aspherical polishing method. This paper describes a method to obtain the local removal rate for the polishing process using bulbous flexible membrane covered with a polishing pad and pressurized by an internal fluid. According to the principle of bonnet polishing and Preston equation, the local removal rate model was established. It is confirmed by the experiments that the local removal depth has a linear relation with the dwell time. Preston coefficient can be calculated from the experimental data. Finally the expression of the local removal rate in bonnet tool polishing is acquired semi-empirically.

Abstract: This paper introduces a new hybrid model for tool condition monitoring (TCM) and optimal tool management (OTM) in end milling operation. The model includes a wavelet fuzzy neural network with acoustic emission (AE) and a model of fuzzy classification of tool wear state with the detected cutting parameters supported by cutting database. The results estimated by cutting conditions and detected signals are fused by artificial neural network (ANN) so as to facilitate effective tool replacement at a proper state or time. The validity and reliability of the method are verified by experimental results.