Study On The High Speed Milling Of Titanium Alloy Based On Cooled Gaseous Nitrogen And Minimal Quantities Of Lubricant Technology

Ti alloy with characteristics of high intensity and light mass is used widely in aero industries. However, the low efficiency of Ti alloy machining has been the problem hard and urgent to solve in aeroplane industries. Based on "green machining", pioneer researches on high speed milling of Ti alloy TC4 with minimal quantities of lubricant carried by cooled nitrogen instead of traditional cutting fluids were done in this paper. The main work was summarized as follows:1. After analyzing the principles and structures of present cryogenic machining equipments for cutting or grinding center, a new method of producing cooled gas by semiconductor refrigeration equipment was proposed; Then based on the works of mathematic evaluation, design and manufacturing of primary parts and experiments for refrigeration performance testing, a new cryogenic machining equipment for cutting or grinding center was developed successfully.2.Under the conditions of nitrogen-oil mixture, cooled nitrogen and cooled nitrogen-oil mixture, the milling force experiments on high speed milling of Ti alloy TC4 were contrastingly done. The variational rules of milling force under different milling media and the variational rules of milling force with miller wear were analyzed respectively.3.The miller wear experiments and Scan Electronic Microscope(SEM) were used to a-nalyze the wear mechanism of miller under the conditions of nitrogen-oil mixture, cooled nitrogen and cooled nitrogen-oil mixture. The results show that comparing with other two media, the cooled nitrogen-oil mixture can reduce the miller wear greatly, increase the tool life and restrain the chip adhesion.