Experiment Research On Grinding Process Of Titanium Alloy

Because of titanium alloy’s superior material properties (high specific strength,corrosion resistance, good heat resistance), it has been more and more applied to theimportant key components in navigation, aerospace and so on. However, the superiormaterial properties make its machinability bad in cutting (grinding). So, the processingquality is difficult to be guaranteed, and the processing efficiency is low. Researchesshow that, the use of new-style ceramic microcrystalline corundum grinding wheel andvitrified bonded CBN grinding wheel can improve its grinding machinability. In order toexplore the microcrystalline corundum grinding wheel suitable to grind titanium and theoptimum grinding parameters; Explore the change rule of that, in the high efficiencydeep grinding of titanium alloy, the grinding force, the grinding temperature and theresidual stress on workpiece surface after grinding, etc. The main contents of this paperare:①The contrast experiment on the grinding force, the surface roughness ofworkpiece and so on with different process parameters of microcrystalline corundumgrinding wheel.②The feature analysis and study on the blocking of microcrystallinecorundum grinding wheel and the forming of abrasive dust.③The high-efficiencygrinding test for vitrified bonded CBN grinding wheel to grind titanium alloy.④Thestudy on the grinding temperature and residual stress after the high-speed and ultrahigh-speed grinding of titanium alloy and the analysis of its metallographic structure.The research results show that:(1)Considering the grinding temperature, surface qualities and the blockage ofgrinding wheels, we should choose grinding wheel with relatively soft hardness levelwhen using the microcrystalline corundum grinding wheel grinding TC4.The bettergrinding parameters for TC4isv s=40m/s,v w=12m/min,a p=0.01~0.02mm.(2)With the linear velocity of grinding wheel increasing from90m/s to150m/s，thegrinding force, grinding temperature shows the tendency of decrease when TC4is inHigh efficiency deep grinding.When the grinding parameters isv s=150m/s，vw=12m/min，a p=0.2mm, the removal rate is40mm3/(mm s), the surface roughness valueis good and surface topography has no burn and crack.(3)Grinding temperature, surface residual stress and microstructure of Titaniumalloy TC4has changed a lot after high speed/ultra-high speed grinding, the grindingtemperature is the main factor of surface residual stress changes. Within a certaintemperature, the higher grinding temperature, the higher the surface residual stress, the lower grinding temperature, the lower the surface residual stress. Surface and thesubsurface micro structure are greatly influenced by the change of linear velocity ofgrinding wheel. When the linear velocity of grinding wheel is120m/s, the grindingsurface appears50~60μm metamorphic layer. When grinding wheel linear velocityincreases to150m/s, the grinding surface metamorphic layer thickness decreases, andthe surface quality improved.Through a large number of experiments analyzed the impact of various processingparameters on the processing quality evaluation factors such as grinding temperature,grinding force, surface roughness, residual stress, surface micro topography, surface andsubsurface damage，the test results have a certain significance.