Papers by Author: Guang Bin Bu

Abstract: In this paper, a milling test for aeronautic aluminum alloy 7050-T7451 was carried out and the cutting force was measured. The least square method was used to make a regression analysis on testing data and the experiential formula for milling was established. The influencing laws of cutting parameters on cutting force were educed, which can offer an important reference for optimizing cutting parameters.

Abstract: In order to articulate the modal change in the whole processing blades, take the finite element method to establish the simulation model of blades and blank remains, and then get the results of blade model with material removal. According to the blades processed vibration characteristics, to perform an experiment on the six different removal blades. The results show that material removal has a great effect on the modal frequency in the processing of blades, which is increasing constantly. The first-order frequency and the second-order frequency in material removal that are about 12 mm and 7 mm don’t reach a maximum and then show a decreasing trend until the completion of processing. Effectiveness of experimental results is verified since simulation results are well consistent with experimental results, which offers a reference for choosing the parameters of blades process and studying three-dimensional vibration mechanism.

Abstract: In this paper, test method was used to study the distribution of cutting force while blade machined with 4-axis and 5-axis NC program. The main difference between the two program was given. The difference of machining forms between 4-axis and 5-axis has led to their cutting forces distribution were different. The change of cutting force in 4-axis machining was large while the 5-axis machining was relatively stable. 5-axis cutting force had no impact comparing with 4-axis, which is more suitable for blade machining.

Abstract: There are two key problems in the manufacture process of impeller with HSM(High Speed Machining). One is the collision between tool and blade, the other is gnawed-cutting arisen by non-uniform change of the cutter axis. The control algorithm of collision-free cutter-axis was described and applied in this paper. The cutter-axis vector was optimized by quaternary linear interpolation method to make normal vector of blade changing continuous, so. These methods were synthetically used in the manufacture experiment. And the qualified impeller was produced. It indicated that the tool vector control method was feasible.

Abstract: The cutting force in manufacture process was observed with Kistler dynamometer. A special clamp was designed to simulate the real condition of blade cutting. Series of experiments were done. Cutting force reflected structure of the blade and movement of machine. Cutting force was changed with feed speed varied and the rotation of axis B & C. Resultant cutting force was uniform in back and basin of blade and increased with cutting speed went up. Resultant force was waved in edge of blade. Back and basin forces were lager than edge force in X direction. Force X invoked vibration.

Abstract: There are two key problems in the manufacture process of impeller, one is the collision of tool and blade, the other is gnawed-cutting arisen by non-uniform change of the cutter axis. UG software was used to solve those problems. Tool tip position was solved by UG. The control algorithm of collision-free cutter-axis was described and applied. The cutter-axis vector was optimized by quaternary linear interpolation method to make normal vector of blade changing continuous, so. These methods were synthetically used in the manufacture experiment. The impeller produced by it was qualified. It indicated that the method of tool vector control was feasible.

Abstract: It was carried out that a HSM test for aluminum alloy (2A70) rotor with carbide cutter. It was investigated and analyzed that the influence of different cutting speed and feed speed on the roughness of blade’s finished surface. The experiment showed that high quality surface was easy to obtain by increasing the cutting speed and decreasing the feed. But when the cutting speed crossed the critical value, increase in the cutting speed caused slight decrease in the surface roughness. The feed decreased to a very small value, the roughness increased a little. It was expected that best surface roughness and machining efficiency could be obtained by selecting the appropriate cutting speed and feed.

Abstract: In large-area HFCVD system, substrate temperature is a key factor which deeply affects the quality of diamond films. It is hard for traditional PID method to control the temperature efficiently. This paper presents a genetic- based PID control scheme for the control of in HFCVD system. Computer simulation and experiment on the system are performed. The results show that the controller designed upon GAs has good dynamic quality and steady-state precision, could meet well the need of the temperature control during depositing diamond films.