| Previous studies have shown that the surface roughness and residual stress,two indicators of surface quality,have a direct impact on the service performance and service life of mechanical parts.The surface roughness will directly affect the friction and wear,fatigue strength,transmission accuracy and fit properties of parts.The surface residual stress will affect the fatigue strength,corrosion resistance and reliability of parts So as to affect the service life of the workpiece.2024 aluminum alloy has excellent comprehensive properties and has been widely used in the aerospace field.It is used to manufacture various high load parts and components,such as aircraft skeleton parts,spacer frame,wing rib,rivet and other parts.After ultra precision machining,the parts can also be used in the fields of nuclear industry,precision instruments and so on.These fields have very high requirements for the surface quality of the parts,which not only requires high precision and small surface roughness,but also requires the residual stress of the machined surface to meet higher requirements.At present,the research on 2024 aluminum alloy is mainly focused on its microstructure and properties and material heat treatment,but the research on its cutting process and cutting parameters is less.Therefore,this paper hopes to study the surface quality after ultra precision turning,so as to provide reference for the preparation of high-quality surface aluminum alloy,and also has important significance for its application in the field of precision.This paper focuses on the finite element simulation and experiment of 2024 aluminum alloy ultra precision turning process,and studies the surface quality.The work is summarized as follows:1.The finite element simulation model of ultra precision turning of aluminum alloy diamond is established.The simulation results of cutting force and cutting temperature in turning process are analyzed,and the reliability of simulation is preliminarily speculated.2.Based on the simulation model,the influence of cutting speed,feed rate and cutting depth on the surface residual stress of workpiece is studied,and the parameters are optimized with the aim of low residual stress.3.The ultra precision turning experiment is carried out,and the causes of surface micro morphology and defects after turning are analyzed.The relationship between spindle speed,feed rate,cutting depth and surface roughness is analyzed by single factor experiment.4.According to the orthogonal experimental results of surface roughness obtained from turning experiments,the prediction model of surface roughness is established.The reliability of the prediction model is confirmed by significance test and experimental comparison.5.The residual stress on the surface of the specimen after the turning experiment is tested,which verifies the reliability of the finite element simulation. |
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