Research And Design Of PLNP Rounding Process And Device For Aero-engine Blade Aerofoil Hole

At present,the air film hole processing method is still mainly used pulse laser,EDM technology and electro-hydraulic beam processing and other three ways to achieve.The common air film hole of the blade will form sharp corners on the side of the hole edge,the existence of these sharp corners,will seriously affect the service life of the blade,and even in the sharp corners sprout fatigue cracks lead to engine failure.Common parts rounding is generally achieved by mechanical method,magnetic grinding method,abrasive grain flow method,abrasive grain injection method,chemical method,electrochemical method and other methods.But the orifice of the inner and outer surface of the air film orifice need to be rounded,especially the orifice of the inner surface is difficult to reach by conventional methods,and the process does not allow damage,touching the blade inner and outer surface of each type of surface,so it is very difficult to achieve the rounding of the air film orifice of the blade.At this stage,some of the air film orifice chamfering is achieved by abrasive flow,but the removal efficiency is low,easy to occur in the inner cavity cooling channel or air film orifice blockage and other problems,and the inner surface orifice chamfering effect is not good,can not meet the advanced engine hollow aircooled blade preparation needs.Known as plasma liquid nano polishing technology,can polish and round off the parts with more complex structure and some small and thin holes.Compared with the current main application of the rounding method,this rounding process uses a low concentration of neutral salt solution and does not require any workpiece shape during the polishing process,so it is more labor-saving,more efficient,low-cost and environmentally friendly.The structure of the aero-engine blade is complex,and the aperture of the air film hole is very small,using the general rounding technology,it is time-consuming and difficult to remove,to address this problem,this thesis is based on the PLNP rounding process for the aero-engine blade air film hole,the purpose is to find the best way to round the aero-engine blade air film hole,to improve the processing quality of the blade air film hole.The whole process of rounding for blade air film holes by PLNP plasma liquid nanopolishing technology is presented from both macroscopic and microscopic aspects.From the perspective of metal elimination,the PLNP plasma liquid nanopolishing rounding technique is described as the result of both physical and chemical reactions,and the process of metal material elimination at the microscopic protrusion location under the dual action of physical and chemical reactions is explained.For the aero-engine blade aerofoil hole inversion technology,a threedimensional drawing of the overall structure is drawn by Solidworks software,and an experimental bench for aerofoil hole inversion of aero-engine blade is built.The spatial structure of the aero-engine blade is analyzed,a special fixture for the engine blade is designed,and the feasibility of engine blade airfoil hole chamfering is analyzed to prepare for the subsequent research.