Research On Friction And Wear Characteristics And Tool Life Of Milling Al-50wt%Si Alloy

Due to its low thermal expansion coefficient,high thermal conductivity,good electrical conductivity,and light weight,Al-50wt%Si alloys are widely used in radio frequency microwave,aerospace vehicle electronic systems,mobile communication systems and other fields.Although the Al-50wt%Si alloy material has excellent material properties,due to the unique forming properties of the material,it is easy to cause serious tool wear and low service life during the cutting process.Therefore,this paper mainly studies the failure mechanism and service life of cemented carbide tools for milling Al-50wt%Si alloy tools.Using the method of combining theory and experiment,through the friction and wear of Al-50wt%Si alloy and cemented carbide The research on the characteristics,the contact friction characteristics between the tool and the chip,the influence of cutting factors on the tool wear mechanism and service life,etc.,provides a theoretical basis for the selection of cutting environment and cutting parameters for actual milling of Al-50wt% Si alloy.This paper mainly conducts research in the following three aspects:(1)The dry friction and wear properties of cemented carbide-Al-50wt%Si alloy were studied.The experimental results showed that the friction coefficient decreased with the increase of load and sliding speed;the main wear mechanism of Al-50wt%Si alloy in the friction process,there are mainly scratches,bonding,peeling,micro pits and other wear forms of cemented carbide,and the wear mechanism is mainly bonding wear and abrasive wear.(2)The theoretical relationship model of the contact friction characteristics between the bevel cutting Al-50wt%Si alloy tool and the chip was deduced.The influence of cutting parameters on the contact characteristics such as the contact length and the average friction coefficient between the tool and the chip is analyzed.friction.It provides theoretical support for the optimization of cutting parameters of carbide cutting tools for milling Al-50wt%Si alloy and the further exploration of cutting tool wear laws.(3)By carrying out single factor and orthogonal design experiments,the influence of cutting parameters,tool material,machining environment and other factors on the service life of milling Al-50wt%Si alloy tools was analyzed,and the influence of tool wear on the machined surface roughness was discussed.The results show that cutting parameters have a great influence on the service life of cemented carbide tools;with the increase of tool wear,the surface roughness of the machined surface first increases and then decreases.Through the full factor orthogonal design experiment,and taking the tool life and surface roughness as the optimization goals,the cutting parameters of carbide cutting tools for milling Al-50wt% Si alloy were optimized.The wear pattern and mechanism of milling Al-50wt%Si alloy tool were studied.The results show that the main wear forms of cemented carbide tools are chipping,built-up edge,bonding edge and scratches;the wear mechanism is bonding wear and abrasive wear.The main wear form of the coated tool is the coating peeling off,and the main wear mechanism is abrasive wear and bond wear.In addition,milling of Al-50wt%Si alloy under MQL conditions improves the bonding phenomenon of the tool.