Papers by Author: Shu Cai Yang

Abstract: On the basis of analyzing the cutting edge structure and cutting edge radius measurement of high-speed insert, thermal - mechanical coupling finite element method (FEM) is used in this paper, to obtain the effect law of different cutting edge radius on the mechanical-thermal distribution of high-speed cutting TiAl6V4. At last, cutting experiments are carried out to verify FEM results. There is a clear exposition of the intrinsic reason why the cutting edge radius has influence on the mechanical -thermal distribution of high-speed cutting process. The results indicate that the experimental results have a good agreement with FEM; with the cutting edge radius increases, cutting force increases; cutting temperature is not monotonic, but there exists an optimum edge radius that makes temperature lowest; cutting edge changes the plastic flow of materials around tool tip and broaden plastic deformation zone. The cutting edge radius has a greater impact on equivalent stress.

Abstract: Polishing is usually the last working procedure of making die surface. The roughness of die surface affects using performance of die directly; therefore, surface roughness is a key factor to scale quality of die surface. The paper focuses on affecting factors of polishing surface roughness, including the rotation speed of polishing head, floating force on polishing head, pass of polishing head movement, feeding rate of polishing head, and size of abrasive particles. Then, establish the parameters database in order to select appropriate technological parameters expediently. These results are used as operating guides for applications of die polisher.

Abstract: According to the principle producing the cutting track of cutter, to study the influence of the cutting track of cutter on the process of high speed ball-end milling, the single-factor models for evaluating the cutting track of cutter are established. Adopting four kinds of the typical cutting track of cutter, the experiment of high speed ball-end milling is processed. The model of multi-ply fuzzy comprehensive evaluation for the cutting track of cutter is established, fuzzy comprehensive evaluation for the cutting track of high speed ball-end milling cutter is accomplished by the application of fuzzy mathematics theory. Results show that the cutting contact curve of cutter affects directly the process of high speed ball-end milling, fuzzy and uncertain properties exist in the evaluation for the cutting track of cutter. The optimum cutting track can be selected by multi-ply fuzzy comprehensive evaluation for the cutting track of high speed ball-end milling cutter.

Abstract: Based on the experiment of high speed milling ball-end milling forces, the model of ball-end milling force is established for high speed machining complex surface by differential method, and research on the principle of high speed ball-end milling force. Results show that the parameters of cutting layer are subjected to varying curvature of complex surface, and place in the unstable state, cutting force decreases as the curvature and the inclination angle increase. By means of lessening cutting speed’s grads and adjusting the inclination angle and the path interval of cutter to the variety of curvature, cutting force and its fluctuation can be depressed availably; the process of high speed ball-end milling can be obviously improved.

Abstract: The smart fluid abrasive (SFA) is a suspension of magnetically soft ferromagnetic particles and nonmagnetic abrasives in a carrier liquid. When the SFA is exposed to a magnetic field, a rapid and reversible fluid-to-solid phase transition occurs. Based on these distinctive features of SFA, a new type of precision finishing technology that can be used in the finishing of the revolved surface has been developed, and the finishing results have been proved in our experiments. In this paper, the SFA finishing mechanism and finishing process are presented, the influence of some basic parameters such as magnetic strength, size of abrasives, time of processing and relative motion between abrasives and working surface of work pieces are discussed as well.

Abstract: Magnetic abrasive finishing (MAF) is a processing technology using magnetic abrasive grain (MAG) under magnetic field to finish surface of workpiece. The magnetic fields used in MAF include permanent magnetic field and electromagnetic field. Two conditions must be taken into consideration in the finishing surface of workpiece. One is the sufficient cutting force; the other is the relative moving speed between MAG and workpiece. The principle of step-motor rotating magnetic field is used to produce rotating magnetic field (RMF) in this paper. RMF brings MAG to rotate and keeps workpiece immovable. Meanwhile, the coins vibrate within a definite angle range and reciprocate in axial direction so as to process the outer cylindrical surfaces. Yoke iron is made of two halves so that the coins for rotating magnetic field will be keyed to some section of heavy crankshaft, thus realizing cylindrical surface finishing on the heavy crankshaft. MAG are of importance to MAF . Six performance indexes related to MAG are suggested by studying on process parameters.