Experimental Research On Machined Surface Quality Of Turning Titanium Alloy TC11

Titanium alloy with its excellent mechanical properties are widely used in aerospace,machinery,medical and other fields,in particular,aero-engine compressor disk and turbine disk and other components.However,titanium alloy as a typical hard-to-machine materials,its cutting performance is poor,high cutting temperature,chemical activity,severe chilling phenomenon and tool wear,seriously affecting the quality of the machined surface parts and reduce the service performance of aviation parts and service life.In order to solve the above problems,this paper focuses on the titanium alloy TC11 were turning surface quality and tool wear were studied,the surface roughness,hardness,residual stress and surface microstructure were analyzed to provide a theoretical basis for the optimization of cutting parameters and tool,in order to achieve high quality and efficient processing of titanium alloy TC11.Specific research contents are as follows:Single factor turning test was designed.The effects of cutting speed,feed rate and cooling conditions on tool wear were investigated under both conventional cooling and high pressure cooling conditions.The effects of cutting speed,feed rate and cooling conditions on the tool wear were studied,and the results were compared with those of uncoated cemented carbide tool.Contrast analysis tool wear form and formation mechanism.The influence of cutting speed,feed rate and tool wear on surface roughness under different cooling conditions was studied by using white light interferometer.The surface roughness of uncoated and coated cutting tools was compared with that of cutting Parameters of the changes.The machined surface was observed by SEM,and the types and causes of surface defects were analyzed.In the case of tool wear,the work hardening of machined surface was studied,and the causes of hardening and its influencing factors were analyzed in detail.The effects of cutting speed and feed rate on the surface hardening degree and hardening layer depth range were studied by using the coated carbide cutting tools.The influence of cutting speed on the work hardening under different cooling conditions was studied.The residual stress and surface microstructure of machined surface were studied.The size and properties of residual stress on machined surface were measured by X-ray diffractometer.The mechanism of residual stress generation was analyzed in detail,and the effect of coating and uncoated tool on surface residual stress was analyzed.The effects of cutting parameters and tool wear on surface residual stress was studied under different cooling conditions.Scanning electron microscope(SEM)was used to observe the surface plastic deformation degree and plastic deformation depth,and the influence of cutting parameters,cooling conditions and tool wear were analyzed.The regularity of grain elongation and twisting of surface layer was analyzed.