Study Of Titanium Alloy Ultrasonic Vibration Cutting Based On Tool-workpiece Contact Ratio

Demand for new materials and performance is increasing with the development ofscience and technology. The high-performance materials have excellent physical andmechanical properties, but at the same time it put forward new challenges to themanufacturing, especially in the forefront of science and technology development fieldof military aviation. Variety of aviation materials cutting performance remains to beimproved, In order to improve the efficiency and quality of the production of newmaterials, new technologies have been put forward. Japanese scientists first proposedthe ultrasonic vibration cutting technology. After continuous development andimprovement, the ultrasonic vibration cutting technology was applied to the actualcutting, as result get the unexpected cutting effect and economic benefit.Ultrasonic vibration cutting is based on conventional cutting and let tool highfrequency vibration. According to the ways of super high frequency vibration，Ultrasonic vibration cutting can be divided into conventional ultrasonic vibrationcutting and elliptical ultrasonic vibration cutting. Two kinds of Ultrasonic vibrationcutting have their own advantages and disadvantages: When the vibration speed of thetool is greater than the speed of the workpiece during the conventional ultrasonicvibration cutting, the tool and the workpiece will separate, but after separation the flankof the tool is in contact with the workpiece surface. This not only increased the toolwear, but also repeatedly rolling on the surface damaged processing quality. Thetrajectory of elliptical ultrasonic vibration cutting is elliptical trajectory, this specialtrajectory can achieve complete separation between the tool and the workpiece, at thesame time cutting thickness changing with time during manufacturing, these changesare very significant to reduce the cutting force and tool wear, but will be roughness Rthin elliptical ultrasonic vibration cutting.In this paper, With the theory of finite element establishes a model of ultrasonicvibration cutting，using finite element software ADVANTEDGE to simulate and analyzethe cutting model. Respectively on conventional ultrasonic vibration cutting andelliptical ultrasonic vibration cutting research, and use the theory of contact ratio ofcomprehensive to analyze the influence of difference cutting parameters in cuttingprocess. The main conclusions as follows:1) Through the finite element theory in combination with the Tool-chip frictionmodel and the Power-law model, establish Ultrasonic vibration cuttingsimulation model based on adaptive ALE method of grid technology. Thecomparison between finite element analysis data and experimental measurementdata found that the error is less than7%, verified the feasibility of the vibrationcutting model.2) Introduce the Theory of contact ratio to research the conventional ultrasonicvibration cutting process, analyze the effect of contact ratio change by differentcutting parameters. Indicate the reason of changing contact force and thermal inthe manufacturing process is contact ratio, can comprehensively analyze theinfluence of different cutting parameters in ultrasonic vibration cutting through thecontact ratio theory.3) Uses the computer software simulate elliptic ultrasonic vibration cutting process,get the path of tool relative to the workpiece is smooth parabola. Theoreticalanalysis was carried out on the finished surface residual roughness height. Analyzethe cutting parameters with the residual roughness height. Discussing the contactratio in the elliptical ultrasonic vibration cutting, analyzing the effect of cuttingparameters on contact ratio. Simulation calculations of elliptical ultrasonicvibration cutting model with different cutting parameters correspond to the effectof contact ratio, verifying the theory of contact ratio.