Tool Wear And Grinding Force In Rotary Ultrasonic Machining Of Titanium Alloy

Due to a serials of advantages of titanium alloy which include high heat and corrosion resistance,specific strength and low density,titanium alloy has been widely used in aerospace industry.There are some crirical problems which result in seriously tool wear and poor surface quality due to high chemical activity of titanium alloy at elevated temperature and low thermal conductivity.Rotary ultrasonic machining(RUM)is a hybrid machining process that combines the material removal mechanisms of diamond grinding and ultrasonic machining.lt includes the abvantages of less tool wear and better surface quality.Grinding force is one of the most significant factor to represent the grinding process.Grinding force not only influences the surface quality of machining tatinium,but also has a significant effect on the tool life.The less tool wear of ultrasonic vibration tool will lead to quickly tool passivation in rotary ultrasonic grinding.The temperature rise in the grinding process will result in problems of surface damage.The more tool wear in the process of grinding will lead to high manufacturing cost due to frequently replace the tool.In order to improve the surface quality of titanium part and decrease the machining cost,it has indicated big significance to conduct the research about grinding force and tool wear in rotary ultrasonic grinding tatinium.Related research about the grinding force and tool wear will be conducted in this paper.Main work in this paper include following four aspects:(1)The three dimensional geometry model of Multi abrasive grain tool which grits is inconsistent and distributed randomly was set up.Finite element prediction simulation model was established by using this three dimensional geometry model of tool.The effect of some machining parameters(spindle speed,feedrate,ultrasonic amplitude,ultrasonic vibration)on grinding force in rotary ultrasonic machining titanium had been investigated through this finite element model and a series of experiment which was consistent with the real experiment condition had been conducted to validate the finite element model.(2)A tool wear model based on dimensional analysis and orthogonal test is established for rotary ultrasonic grinding tatinium alloy.With this model,the non-linear relation between tool wear in rotary ultrasonic grinding titanium and process parameters and tool parameters can be quantitatively solved.The ANOVA analysis was used to check the effectiveness and significance of the tool wear model.(3)Secondary development for finite element software Deform-3D had been completed by using the program language Fortran.Different wear model corresponding to different wear mechanism was combined into a subroutine in Deform.Finite element wear model for rotary ultrasonic grinding titanium was set up and the effect of abrasive size on tool wear for roatry ultrasonic grinding was investigated.It indicates that the tool wear model has relatively high prediction accuracy.