Papers by Author: Chang Feng Yao

Abstract: The orthogonal experiment is processed for high-speed milling superalloy GH4169 with TiAlN coated carbide inserts. The surface roughness prediction model based on cutting parameters is established by using the least-squares regression method. And the effect of cutting parameters on surface roughness is studied. According to the prediction model of surface roughness, a model of cutting parameters optimization by using genetic algorithm based on annealing penalty function is established for maximum material removal rate under specified surface roughness values. Obtain the optimal parameter combination when the surface roughness Ra≤0.2µm, and the experimental validation is done. These results provide the basis for improving processing efficiency of processing GH4169 and choosing parameters under specified constraint conditions.

Abstract: In order to provide experimental evidence for optimizing high-speed milling parameters and controlling surface integrity, the effects of cooling conditions, tool rake angle and milling parameters on machined surface residual stresses were investigated in high-speed milling titanium alloy TC11. The residual stresses were measured by XStress3000 X-ray stress analyzer, and three points were tested on each workpiece surface, then take average. The milling parameters were optimized based on fatigue performance. The results show that the emulsion cooling get the highest surface residual compressive stress and the dry cutting get the lowest residual compressive stress. With the increasing of cutting tool rake angle, surface residual compressive stresses increase. The most effect on the residual stresses of surface is milling width, next are feed per tooth and milling depth, and the last is milling speed. In the experimental range, the optimized high-speed milling parameters are: vc=377m/min, fz=0.03mm/z, ap=0.2mm, ae=7.5mm.

Abstract: The paper is concerned with the effect of cutting parameters on surface microstructure of titanium alloy TC17 in high speed milling with the carbide cutting tools by single factor experiment. It will be provided experimental evidence for optimization cutting parameters and surface quality control of titanium alloy parts in high-speed cutting process. It is observing microstructure with Germany's Leica DMI 5000M inverted metallurgical microscope. The results show that in the range of experimental parameters, the effect of milling speed, feed per tooth and milling depth on surface microstructure in high-speed milling of titanium alloy TC17 is little. There is no obvious phase change, as indicating that most of the heat generated by chip away, little heat incoming workpiece, under the conditions of high speed milling titanium alloy TC17.

Abstract: The paper is concerned with the effect of cutting parameters on surface microhardness in the high speed milling of titanium alloy TC17 with carbide cutting tools by single factor experiment. To provide experimental evidence for process parameter optimization and surface quality control in high-speed cutting titanium alloy parts. The results show that to aim for lower hardening layer depth, cutting parameters can be optimized as: vc=391.7m/min, fz=0.05mm/z, ap=0.45mm. The effect of cutting parameters on microhardness has experienced surface hardening-softening - re-strengthening - the process of stabilizing，in the experimental range.

Abstract: To study of the temperature generating mechanism of Titanium Alloy Ti - 6Al - 4V in high speed, and the influence rule of the milling process parameters for milling temperatures, A temperature simulation model of the milling process was found with AdvantEdge, the relationship between the high speed milling parameters and the milling temperature of Titanium Alloy Ti - 6Al - 4V was discussed by the finite element simulation, and the milling process temperature was measured by the half artificially thermocouple methods. The result show that the highest temperature are reached at close to the tool tip in the rack face, the feed per tooth have significant effect on the milling temperature, while cutting depth and milling width have little effect. The milling temperature increase with the feed per tooth increasing，the highest temperature increase with the spindle speed increasing.

Abstract: Finite element method (FEM) is a powerful tool to predict cutting process variables such as temperature field which are difficult to be obtained from experimental methods. The turning process of Inconel 718 is simulated by AdvantEdge which is professional metal-cutting processing finite element software. The effects of cutting speed, feed and cutting depth on cutting force and temperature field are analyzed. The results show that cutting forces decrease with cutting speed increasing, and increase with feed and cutting depth, and the influence of cutting depth on cutting forces is significant. The maximum temperature in the cutting zone located on the rake face at a distance of about 0.01 mm from the tool tip. As cutting speed and feed increase, the maximum temperature in the cutting area increases. The influence of cutting speed on cutting temperature is significant, but the cutting depth has little impact on temperature.

Abstract: In order to provide theory basis for optimizing high-speed milling parameters, the high-speed milling process of titanium alloy Ti-6Al-4V was modeled using the commercial general purpose machining software package ADVANTEDGE. Effects of milling parameters like milling speed, feed per tooth, milling depth and milling width on cutting force and temperature were analyzed. The results show that cutting forces decrease with milling speed increasing, and increase with feed per tooth, milling depth and milling width, and the influences of feed per tooth, milling depth and milling width on cutting forces are significant. The maximum temperature in the cutting zone located on the rake face at a distance of about 0.02~0.03 mm from the tool tip. As milling speed and feed per tooth increase, the maximum temperature in the cutting area increases. The milling speed has significant impact on cutting temperature, but the milling depth has little impact.

Abstract: Precision machining of thin-walled complex components has been a serious challenge, and the machining errors are mainly due to cutting force which can induce tool-workpiece deformation and chatter vibration phenomenon. Based on the principle of stiffness optimization and material removal sequence optimization, rigidity of thin-walled component is greatly improved with non-uniform allowance distribution and spiral milling process techniques.