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In the process of nickel-based alloy machining, chips are easy to bond on the tool surface, which weaken the tool performance and make the tool wear. Therefore, it is very important to study the mechanism of tool bond wear in the process of nickel-based superalloy machining. In order to reflect the wear process of the tool from the perspective of micro cutting, the molecular dynamics simulation model for cutting Ni–Fe-Cr-Co–Cu nickel-based alloy with SiC tool was established. The Morse potential functions between the tool and workpiece are calculated, and the simulation results are analyzed visually. It is found that the bond wear is the main wear form of tool in the process of cutting nickel-based alloy, and the wear processes are divided into three stages: contact, adhesion and shedding. The stress and strain in the cutting area are calculated and it is found that the bond occurs when the tool-workpiece extrusion is strong. Through the calculation of radial distribution function and formation energy, it is found that Ni-Si compound is formed on the tool surface, and the newly generated Ni-Si compound reduces the tool performance compared with the silicon carbide structure. This study provides a more complete microscopic explanation of the tool wear mechanism, which is helpful to find a method to prolong tool life.

Because nickel-based alloy Inconel718 has poor thermal conductivity and serious work hardening, it is identified as a difficult-to-process material. The serious tool wear leads to short tool life. In this study, physical vapor deposition-coated carbide tools were used to machine Inconel718. The material response for different cutting speeds at the tool–chip interface and its effect on tool wear were studied. The results showed that at low cutting speed (v c = 20 m/min), cold welding and adhesion occurred at the tool–chip interface under high stress, and then the built-up edge (BUE) formed. The peeling off of BUE led to chipping. When the cutting speed (v c) was 45 m/min, diffusion and oxidation occurred at the tool–chip interface. The new generated material reduced tool hardness and bond strength of Co. The wear debris was generated in tool rake face. Flakes of wear debris fell from the tool substrate, which increased tool wear. When the cutting speed was 32 m/min, the softer oxides generated at the tool–...

Ti6Al4V has great affinity with tool material in machining process, which easily leads to tool diffusion wear. Turning experiments were carried out to study cutting temperature and pressure at tool-chip/workpiece. Based on the analysis, a scanning electron microscopy (SEM) equipped with energy dispersive X-ray spectrometer (EDS) was used to analyze tool wear morphology. The affinity of tool and workpiece material using the Ti-W, Ti-Co diagram was also studied to elaborate the diffusion mechanism in this present study. The results shows that the cutting temperature is very high and the temperature increases with the increase of cutting speeds in machining Ti6Al4V. At the contact area, the highest temperature is located in tool rake face near to tool tip. The resilience of workpiece results in serious attrition between tool flank face and the machined surface. The highest pressure is located in tool flank face near to tool tip and the pressure in tool-workpiece interface is much higher than that in tool-chip interface. Under the high cutting temperature and high pressure at tool-chip/workpiece interface, diffusion occurred both at tool rake an flank face in machining Ti6Al4V. Because of the higher temperature at tool rake face diffusion at tool rake face ia more sever than that at tool flank face.

Nickel-based alloy Inconel718 is a difficult-to-cut material due to lower thermal conductivity, affinity to react with tool material, the cutting tools wear very rapidly due to the high cutting temperature and high cutting force. It is important to choose tool material reasonably. In this paper, cutting performance of the multi-layer CVD-coated (TiN/Al2O3/TiC) tool and PVD-coated (TiAlN) tool were evaluated by cutting temperature, cutting force, tool wear and tool life. The results showed that PVD-coated (TiAlN) tool was suitable for cutting Inconel718.

Motorized spindle thermal deformation is a major factor affecting the accuracy of high-speed machine tool, previous studies have focused on asynchronous motorized spindle, however, in this paper, permanent magnet synchronous motorized spindle is the research object. At first, the finite element model of thermal characteristics of motorized spindle is established base on its thermal characteristics analysis. The second, study on the distribution of the spindle steady-state temperature field, effect of spindle speed and bearing lubrication on thermal deformation of spindle. The results provide a strong theoretical basis for the design and use of spindle.

Nickel-based super alloy GH4169 has been widely used in aerospace industry because of its good mechanical properties under high temperature. However, it is difficult to machine for its high strength, poor thermal conductivity and serious work-hardening. The effects of tool geometric parameters on tool life are studied by machining experiments using YG8 tools with different cutting edge angle in this paper. The tool with cutting edge angle 45°has longer tool life than 75°. The cutting experiments have been carried out using TiAlN (PVD) coated tools (AC520U) with different rake angle. It shows that the tool life with rake angle 9° were increased by 50% and 25% compared to tool with rake angle 3°and 6° when cutting speed is 30m/min. The tool with rake angle 9° is not suitable for cutting GH4169 when cutting speed is more than 35m/min. The results show that geometric parameter of cutting tool is one of the important factors affecting tool life.

Nickel-base super alloy GH4169 is difficult to cutting and tool wear is very serious, because of its high strength, poor thermal conductivity, and serious work-hardening. In order to choose reasonable cutting parameters as to improve the processing efficiency, the cutting experiments were crarried out and the changes of workpiece material physical in cutting process were studied, and then thermostatic cutting method based on the longest distance is proposed in this paper. The best cutting temperature of carbide cutting tool YG8-GH4169 has been given. The experiments using diferent cutting parameters has proved the feasibility of thermostatic cutting method. Finally, the empirical formula of thermostatic cutting based on the cutting speed and feed rate is proposed, when using YG8 cutting GH4169.

In dry machining titanium alloys, tool wear is serious and machining efficiency is very low due to its low thermal conductivity and high chemical activity. The uncoated cemented carbide tool was used for the experiments of turning titanium alloy Ti-6Al-4V. Based on analysing the tribological characteristic of tool-chip and tool-workpiece interface using FEM, a scanning electron microscopy (SEM) equipped with energy dispersive X-ray spectrometer (EDS) and X-ray photoelectron spectroscopy were used to analyse tool wear mechanism. The results showed that there existed great differences of the friction between tool-chip/workpiece interface and general friction. There existed serious adhesion, diffusion and oxidation at the tool-workpiece interface. There was an optimal cutting condition under which the equilibrium of oxidation wear and adhesion wear can be achieved, which made tool wear reduce.