| In the aerospace industry,aircraft structure design,material properties,manufacturing technology and so on need constant research and innovation.Among many materials,it is found that titanium and aluminum alloy are superior to other materials in many aspects,for example,they have incomparable advantages in specific strength and oxidation resistance,so they are favored by the aviation industry.Because a large number of parts are needed for assembly in aviation industry,and the assembly needs a large number of holes for connection,the processing technology of drilling holes needs to be improved.A single material property may not meet engineering requirements,but two different material lamination can ensure the advantages of the material while improving the shortcomings of the material.Making different materials into laminated structure is beneficial to the later processing of engineering and also improves the properties of materials while avoiding the disadvantages of single materials.There are many inevitable defects in the use of traditional twist drills to drill titanium and aluminum laminate materials.The gap between the characteristics of aluminum alloy with low hardness and titanium alloy with high hardness leads to increased export burr in drilling,the lamination shadow between the lamination layers is also very large,and the surface of the inner wall of the hole is too rough to meet the processing requirements and many other problems.In view of the above problems,this paper USES two methods to improve the disadvantages of traditional twist drill cutting laminated materials.One is to use geometric tool instead of twist drill to improve the disadvantages of laminated material drilling,the other is to add ultrasonic vibration on the basis of the traditional drilling,to change the traditional way of processing.(1)The traditional twist drill of ti-6al-4v/al2024-t351 laminated materials and ultrasound-assisted drilling(UAD)with the addition of ultrasonic assisted drilling(UAD)were modeled by finite element simulation using deform-3d software.The validity of frequency and spindle speed is discussed.The purpose is to investigate the effect of UAD on machining performance and compare it with conventional drilling(CD)to prove that UAD technology can achieve better hole quality.Specifically consider the following aspects: the length of the chip generated by CD and UAD,the size of the lamination generated by the laminated material,the change of the temperature inside the workpiece during the drilling process and the change of the effective stress inside the workpiece during the drilling process.It is concluded that ultrasonic assisted drilling can effectively reduce thrust force,delamination layering and effective stress chip length.(2)The traditional twist drill has such problems as large thrust force,large burr at the outlet and poor surface morphology.To solve these problems and reduce damage,low amplitude and high frequency vibrations are usually added to the direction of feed motion.This paper focuses on the study of geometric tool CD and UAD.Under ideal experimental conditions,the drilling of laminated materials is studied by combining experiment with simulation.It is concluded that ultrasonic vibration drilling can reduce the thrust force,temperature,burr length and effective stress of drilling.(3)When conventional twist drills are used to drill al2024-t351 / ti-6al-4v laminated materials,problems such as large thrust force,serious delamination,high temperature and serious damage to surface quality exist.To solve these problems,special geometric tools are often chosen for drilling.This paper focuses on CD and UAD exploration of multi-point drilling.Under ideal experimental conditions,the drilling process of laminated materials is explored by combining experiments with finite element simulation.It is concluded that ultrasonic vibration drilling can reduce the hole diameter deviation,delamination factor,drilling temperature,outlet temperature and wall damage. |
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