| Bulk amorphous alloy has been widely used in aerospace,automotive power,medical care and other fields,and has become a new material with wide application potential.Drilling with high removal rate and high efficiency is one of the main processes for manufacturing holes with high dimensional accuracy and high casting surface quality.Poor hole quality can cause cracks and reduce reliability.In order to provide a suitable drilling processing scheme for amorphous alloy and obtain better drilling quality,this paper takes Zr based bulk amorphous alloy Zr52Cu17.5Ti16Ni12Nb2.5 as the research object,and studies the drilling characteristics of bulk amorphous alloy by combining experiment and simulation(1)Study on deformation behavior and drilling mechanism of amorphous alloy.The chip deformation mechanism in orthogonal cutting of Zr based bulk amorphous alloy and the calculation of shear yield stress,temperature and strain rate in the cutting process are studied.The formation mechanism of amorphous alloy chip was analyzed through the study of chip fracture.At the same time,the geometric parameters of the bit structure and drilling parameters are studied,and the mathematical model of axial force and torque calculation is established.(2)Simulation Research on drilling process of amorphous alloy.By using DEFORM-3 D finite element software,the constitutive model of the selected amorphous alloy is constructed,and the changes of drilling force,cutting temperature,stress and strain field,as well as the influence of cutting parameters on drilling force are analyzed.The macro morphology of chip and surface quality of machined hole are analyzed,and the drilling process parameters of amorphous alloy are explored.(3)Experimental study on drilling technology of bulk amorphous alloy.Based on the theory of drilling technology and the deformation mechanism of amorphous alloy,the experimental scheme is designed according to the simulation results.Through the single factor drilling experiment,the influence of different processing parameters,different tool materials,tool coating and tool structure on the cutting force and surface quality and tool wear are analyzed.The chips produced by drilling under different conditions were collected,and the change of chip types and morphology characteristics were observed.The process scheme suitable for drilling amorphous alloy materials was given.In this paper,Ni based single crystal superalloy,304 stainless steel and 6061 aluminum alloy with similar characteristics are selected to carry out comparative processing experiments.The results show that the drilling process of amorphous alloy is feasible. |
PDF Full Text Request