| Titanium alloy is an engineering material widely used in Aeronautics and Astronautics,petrochemical industry and medical hygiene because of its strong corrosion resistance and high specific strength.But its low thermal conductivity,high cutting temperature,severe cold hard phenomenon and small cutting deformation coefficient make it a typical hard working material.Therefore,the high-efficiency precision machining of titanium alloys has always been a technical problem in the cutting field.A large number of studies have shown that the external field assisted machining is an effective method to solve the high efficiency and precision cutting of titanium alloy,and the vibration assisted machining has a recognized effect in the field of hard material cutting.In this paper,the vibration aided side milling test of TC4 titanium alloy under different technological and technological parameters was carried out by applying vibration to the workpiece,and its technological effect was deeply studied.The specific research of this article is as follows:1.Based on the principle of ultrasound,a set of driving system for ultrasonic vibration milling is developed,and the structure size of the workpiece is determined by theoretical calculation,and the amplitude output of the ultrasonic vibration system is measured.Based on the reverse piezoelectric effect of the piezoelectric actuator,a set of piezoelectric vibration worktable for low frequency vibration milling is designed,and its output characteristics are analyzed.The results show that the output performance of the two sets of devices is continuous and stable,and can meet the needs of actual processing.2.The vibration of the workpiece is applied in the direction of feed(tangential)and perpendicular to the direction of the machined surface(normal)in the axial direction(axial)of the cutting tool.The kinematic characteristics of three directional cutting tools relative to the workpiece are analyzed,and the necessary conditions for cutting the cutters to separate the cutters are obtained.The test parameters were selected.3.A single factor test of spindle speed,amplitude,and feed per tooth is carried out on the basis of ultrasonic vibration applied in three directions.According to the analysis of kinematic characteristics,the conditions of the separation of the cutters are compared and analyzed in different direction of vibration,the effect of ultrasonic and low frequency vibration on the cutting force,and the experimental results show that the vibration milling is used.It has the effect of reducing the average force,and the force reduction effect of ultrasonic vibration milling is better than that of low frequency vibration milling.4.On the basis of different vibration modes applied to the workpiece,the influence of three vibration directions and two types of vibration frequency of ultrasonic and low frequency on surface roughness and surface morphology,surface microhardness and residual stress are analyzed.The experimental results show that the regularity of ultrasonic vibration milling surface micro texture is better than low frequency vibration milling,and the surface microhardness and residual stress have a certain correlation with the cutting force.The lubrication effect of pouring lubrication and micro lubrication(MQL)in vibration assisted milling is compared and analyzed.Through the research carried out in this paper,the exciting device suitable for vibration assisted milling is developed,and the influence law of the vibration mode on the titanium alloy milling is revealed,and the processing advantages under various vibration modes are explored,thus providing theoretical guidance and technology for the industrial application of the vibration aided milling technology. |
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