| Titanium alloy with its excellent performance,widely used,but at the same time because of the unique performance,leading to complicated processing technology,high production cost.In the finishing stage,there are some problems,such as surface burn and surface hardening caused by cutting heat and "sticky grinding wheel" of titanium alloy,which seriously affect the service performance and life of titanium alloy workpiece.At the same time,great progress has been made in the application of MR technology in the metal field.Some foreign scholars have used MR technology to smooth the medical titanium alloy sheet and achieve a higher surface quality.However,there is still a lack of data on the processing of titanium alloy bars by MR technology at home and abroad.Therefore,This subject uses the "flexible machining"magnetorheological technology to carry out finishing experiments on the commonly used TC4 titanium alloy,aims to study magnetorheological technique can effectively finishing machining surface of titanium alloy rod,for finishing machining titanium alloy rod new processing method,for magnetorheological technology application on the titanium alloy rod.The research content of the subject includes the following five parts:firstly,the mechanism of MR finishing is analyzed,analyzing the force of abrasive particles from the perspective of particles,theoretically determined the main influencing factors affecting magnetorheological finishing.Secondly,studied the magnetic field homogeneity of the influence of the magnetic-rheological polishing the surface of the machined part quality by designing the rectangular and T iron parts to improve the uniformity of magnetic field,combined with Maxwell simulation results and the measured magnetic induction intensity of the processing area before and after the improvement,as well as experimental verification,the processing area is obtained more uniform distribution of magnetic induction intensity can reduce the workpiece surface roughness,surface polishing efficiency,the improved more uniform magnetic field distribution for the magnetorheological finishing processing magnetic field work provide a good environment.By studying the influence of magnetorheological polishing liquid preparation process and polishing liquid base liquid type,carbonyl iron powder mass fraction,abrasive type,etc,on the surface roughness of titanium alloys.Obtained the magnetorheological polishing liquid composition,proportion and preparation process required for finishing TC4 titanium alloy.After testing the performance of the polishing fluid,the results show that the polishing fluid has the characteristics of low viscosity and high shear stress.The influence of four main process parameters(grain size,magnetic induction intensity,workpiece speed and finishing time)on the surface roughness of titanium alloys is analyzed by single-factor experimental research.And studied the influence of magnetorheological technology on the surface texture,surface composition,surface hardness and residual stress of titanium alloy.Obtained that the magnetorheological technology can effectively finish the TC4 titanium alloy.At the same time,no problems such as surface hardening and burns occurred on the machined surface of the workpiece.Finally,response surface method is used to analyze magnetorheological finishing machining of TC4 titanium alloy,abrasive abrasive,magnetic induction intensity,the workpiece speed and processing time interaction influence on workpiece surface roughness,obtained the optimum technological parameters combination,it has been verified by experiment that magnetorheological finishing machining of TC4 titanium alloy after surface roughness can reach 0.1 mu m or so.The research results show that the magnetorheological technology can effectively finish TC4 titanium alloy bars,and better surface quality can be obtained under the appropriate process parameters.The magnetorheological technology can be used as the finishing method of titanium alloy bars. |
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