Research On Turning Temperature And Turning Vibration Characteristics Of TC4 Titanium Alloy Under Dry And Wet High Speed Turning

Titanium and titanium alloys,which are called "strategic metals of the 21 st century," are widely used in various fields such as aerospace and marine engineering,but titanium alloy is typical hard-to-cut material.During the machining process,tool wear is severe and the coupling of the turning temperature and turning vibration generated change with time.How to design reasonable processing parameters and processing techniques for reducing tool wear in titanium alloy cutting,and developing an effective online tool condition monitoring method have always been a challenge.This subject combines the theory and experiments to study the turning temperature and turning vibration characteristics of TC4 titanium alloy under dry and wet high speed turning.The main research results are as follows:(1)A synchronous signal acquisition system for turning temperature and turning vibration was set up.The temperature measurement test system uses an infrared thermometer to collect the turning temperature of the tool tip during the cutting process.The vibration measurement test system uses a vibration meter and a three-direction vibration accelerations sensor to collect the tool's vibration signal.A multi-level orthogonal test scheme was designed for dry turning and wet high-speed turning tests on TC4 titanium alloys.Based on experiments,the time-domain signals of turning temperature and turning three-direction vibration accelerations under different turning factors were collected,and the time-domain characteristics of turning temperature and turning vibration in more than 100 different turning tests were obtained.(2)According to the turning temperature and turning vibration characteristic signals,the effects of three cutting parameters on turning temperature and three-direction vibration accelerations are analyzed by using single factor analysis.The influence of turning parameters on chip morphology of titanium alloy was also briefly analyzed simultaneously.Combined with the scan chart of tool wear,the close relationship between tool wear,turning temperature and turning vibration is further analyzed.(3)Based on the test data of more than one hundred groups of subjects,the effects of multiple turning parameters on turning temperature and turning vibration under different turning conditions were studied in a deep and systematic manner.The grey correlation theory is used to analyze the numerical correlation between the turning temperature and turning vibration of titanium alloys under dry and wet turning conditions.The results show that the values of grey comprehensive correlation between turning temperature and turning vibration during dry and wet turning of titanium alloys are both 0.75 and above,indicating that there is a strong relationship between turning temperature and three-direction turning vibration.(4)Based on the least square method,a regression model of the turning temperature on vibration acceleration and the three elements of turning is established.The correlation coefficient is calculated by MATLAB programming to obtain a fitting formula.The results show that the correlation between turning temperature and turning vibration can be maintained at 0.70 and above under the conditions of dry turning and wet turning of TC4 titanium alloy,which also shows that the mathematical model established in this paper can theoretically predict the TC4 titanium alloy cutting turning temperature changes during the process.There are 57 papers,33 tables and 90 references.