Analysis On Wear Failure Mechanism And Remanufacturing Life Extension Technology Of Aviation Piston Engine Cylinder Block

In order to deeply study the usage rule of aviation piston engine,find the wear and tear characteristics of aviation piston engine cylinder block,study the corresponding repair technology,so as to realize the mapping relationship between wear failure and repair mode to the maximum extent.Aviation piston engine wear failure mechanism and remanufacturing life extension technology mainly take Lycoming IO-360 series aviation piston engine cylinder block with high occurrence and easy failure as the research object.Analyzing the aviation piston engine cylinder block of friction and wear failure mechanism,establish a flight cycle power-load spectrum,the cylinder block evaluation used to manufacture of cylinder block,contrast analysis of cylinder block and manufacturing technology and technical characteristics of the regular repair,Determine the inner hole plasma thermal spraying technology for cylinder block of remanufacturing technology,design system and the preparation of TiO₂-CNTs coating materials,analyses the reinforcement mechanism and mechanical properties of the TiO₂-CNTs coating,simulate the real conditions of coating tribological tests,further study on aviation piston engine remanufacturing coating of cylinder block of stress strain and fatigue life cycle assessment with technology application level of risk analysis.Firstly,based on the tribology principle,the friction and wear failure mechanism of the cylinder block of aviation piston engine under the characteristics of full power operation,intermittent operation and unstable cooling operation is systematically analyzed.According to the typical working states of the aircraft piston engine,such as ground cold start,ground warm-up,take-off and climb,entering the maximum continuous working state and economic speed cruise,the power-load spectrum of the aircraft piston engine cylinder block is established.analyzed the remanufacture ability of waste cylinder block was quantitatively analyzed by AHP.The application characteristics,technical advantages and development trend of conventional repair technology and remanufacturing life extension technology were analyzed.By comparing the application characteristics and technical advantages of various remanufacturing technologies,the inner hole plasma thermal spraying technology was used to repair the inner wall of cylinder block.Furthermore,the spraying material system is designed from the aspects of tribology,forming quality and spraying economy.The strengthening mechanism,friction reduction and lubricity of the 42Cr Mo alloy structural steel are compared with that of the cylinder block material of Ni Mo Al Y+Cr₂O₃+Ag+Ca F₂ and TiO₂-CNTs.The ultrasonic dispersed TiO₂-CNTs particles are determined and prepared as the spraying material.The strengthening quality of the pre-sprayed layer on the cylinder block was tested from the aspects of microscopic coating analysis,strengthening mechanism analysis,friction and wear resistance and self-lubrication performance test.Two methods and two dimensions were used to analyze the CNTs phase structure,microstructure transformation,crack segregation,bridge and elongation in the plasma spraying process to avoid the initiation and development of cracks.The addition of refine the grain,increase dislocation,enhance the hardness and stability of the coating itself（not easy to peel）;The wetting property of TiO₂ droplet itself and the bridging effect of capillarity enhance the stability of TiO₂ coating,and summarize the influence of coating strengthening effect on cylinder life extension.Real spraying again and used in study of the inner wall of the cylinder block,and the simulation of real working conditions of the waste gas cylinder inside coating tribological testing,inspection and the combination of strength and mechanical properties,42Cr Mo alloy structural steel research found that coating made of the surface of the TiO₂-CNTs cylinder body,in the warm air piston engine starting machine,friction losses in cylinder kept at lower level（lower than the original cylinder block）;In the economic cruising state,the friction coefficient（cylinder wear degree）keeps a low growth level;In the maximum continuous state（take-off or maneuvering）,the wear in the cylinder remains in the reasonable wear state,and does not change with the drastic change of the working condition.From the experimental point of view,the TiO₂-CNTs coating not only has good wear resistance,and this ability changes slightly with the drastic change of extreme conditions,or even unchanged.Finally,the oxidation fatigue life model of ceramic materials was established,the stress,strain and fatigue life of the coating were analyzed by ANSYS coupling transient field module,and the particle swarm optimization ELAMAN neural network risk diagnosis model was established to evaluate the coating wear risk.The risk assessment model can well predict the level of coating wear risk.