Xinchun Huang

Influence of high-speed milling parameter on 3D surface topography and fatigue behavior of TB6 titanium alloy

High-speed milling of titanium alloys is widely used in aviation and aerospace industries for its high efficiency and good quality. In order to optimize the machining parameters in high-speed milling TB6 titanium alloy, experiments of high-speed milling and fatigue were conducted to investigate the effect of parameters on 3D surface topography and fatigue life. Based on the fatigue fracture, the effect mechanism of surface topography on the fatigue crack initiation was proposed. The experiment results show that when the milling speed ranged from 100 m/min to 140 m/min, and the feed per tooth ranged from 0.02 mm/z to 0.06 mm/z, the obtained surface roughness were within the limit (<0.8 μm). Fatigue life decreased sharply with the increase of surface equivalent stress concentration factor. The average error of fatigue life between the established model and the experimental results was 6.25%. The fatigue cracks nucleated at the intersection edge of machined surface.

Effect of cutting parameters on machinability characteristics in milling of magnesium alloy with carbide tool

Magnesium alloy has attracted more attentions due to its excellent mechanical properties. However, in process of dry cutting operation, many problems restrict its further development. In this article, the effect of cutting parameters on machinabilities of magnesium alloy is explored under dry milling condition. This research is an attempt to investigate the impact of cutting speed at multiple feed rates on cutting force and surface roughness, while a statistical analysis is adopted to determine the influential intensities accurately. The results showed that cutting force is affected by the positively constant intensity from feed rate and the increasingly negative intensity from cutting speed. In contrast, surface roughness is determined by the gradually increasing negative tendency from feed rate and the positive effect with constant intensity from cutting speed. Within the range of the experiments, feed rate is the leading contribution for cutting force while the cutting speed is the dominant factor for surface roughness according to the absolute intensity values. Meanwhile, the trends of influencing intensities between cutting force and surface roughness are opposite. Besides, it is also found that in milling magnesium alloy, chip morphology is highly sensitive to cutting speed while the chip quality mainly depends on feed rate.

Surface integrity in high-speed milling of Titanium alloy TC11

The study focuses on the machined surface integrity of titanium alloy TC11 under different cutting conditions. Residual stress, surface roughness and microstructure were investigated. Three cutting speeds were selected as 376.8 m/min, 471 m/min, and 565.2m/min. In addition, three different cooling methods including dry, emulsion liquid and oil mist were selected. The results show that the surface residual stresses are compressive under all cutting condition. The compressive residual stresses decrease with the milling speed increasing both in feed and stepover directions. When the milling speed increases, surface roughness increases obviously. The lowest residual stress and surface roughness are obtained when the emulsion liquid is used as cooling method. The microstructure of surface layer is not obvious changed; phase transition and undesirable deformation of grain are not found under all cutting condition. Emulsion liquid cooling is the best cooling method in high-speed milling of titanium alloy with uncoated cemented carbide tool.

Simulation of effect of milling parameters on milling force in High-Speed Milling of titanium alloy TC4

A finite element model of milling process of TC4 titanium alloy was developed with AdvantEdge. The influence of milling parameters on milling force was simulated in the High-Speed Milling process with cemented carbide tool. These milling parameters contain spindle speed, feed per tooth, milling depth and milling width. The absolute sensitivity of milling parameters on the milling force was analyzed with the sensitivity analysis method. The results show that feed per tooth and milling depth have significant effect on the milling force, while spindle speed and milling width have little effect. The milling forces decrease with spindle speed increasing, and increase with feed per tooth and milling depth increasing.