Study On Semi-solid Casting-rolling Processing And Post-treatment Of Steel-Al-5Gr Bonding Plate

As an ideal new-type self-lubricating bearing bush,steel-backed aluminum-graphite bonding plate combines the high strength,high rigidity of steel with the high thermal conductivity,light quality of aluminum-graphite,which is widely being used in military industries and civil applications.To improve the interface bonding properties of steel-backed aluminum-graphite bonding plate,the semi-solid casting-rolling processing optimization and post-treatment of bonding plate are studied in this dissertation.Specific research works are as follows:The semi-solid slurry of aluminum-5graphite is prepared with evenly distributed graphite particles by the mechanical-electromagnetic stirring technology in the preparation research of aluminum-5 graphite semi-solid slurry.Moreover,the influence rule of the solid fraction to the graphite particles homogenization is identified.In the semi-solid casting-rolling processing research of steel-aluminum-5graphite,the heat-fluid coupled numerical simulation of the semi-solid casting-rolling process is carried out,range of the semi-solid casting-rolling processing parameters is preliminary identified.And the following research results are got on basis of the range of the semi-solid casting-rolling processing parameters:? According to the research on mechanical properties of the semi-solid casting-rolling bonding interface,the relationship among the solid fraction,the casting speed,the preheat temperature and the steel-aluminum-5graphite semi-solid casting-rolling bonding plate interface bonding strength is got.? According to research on the structure of semi-solid casting-rolling bonding interface,the composition of the semi-solid bonding interface is identified.And the formation mechanism of the steel-aluminum-5graphite semi-solid casting-rolling bonding plate interface structure is presented.? The semi-solid casting-rolling processing optimization strategy is proposed based on the response surface method and the simulated annealing algorithm,and the reasonable processing condition of the steel-aluminum-5graphite semi-solid casting-rolling bonding plate is determined.Post-treatment of the steel-aluminum-5graphite semi-solid casting-rolling bonding plate is carried out.First,the numerical simulation of the rolling post-treatment with small deformations is carried out using the elastic-plastic finite element method,and the reasonable range of reduction rate is preliminary identified.On basis of the range,the rolling post-treatment with small deformations of the steel-aluminum-5graphite semi-solid casting-rolling bonding plate is carried out.The relationship between the reduction rate and the interface shear strength of the bonding plate is established,the processing condition of rolling post-treatment with small deformations is got,under which the interface shear strength is maximum.The semi-solid bonding pattern is adopted in this research.A novel interface structure,which eliminates the interface embrittlement,composed of alternating Fe-Al compound and Fe(Al)sosoloid is got.Using the rolling post-treatment with small deformations,the residual stress of interface is eliminated,which promote the interface bonding properties,provide an efficient path to improve the shaping quality and lay the foundation for enlarge the scopes of application in various economic field of steel-backed aluminum-graphite bonding plate.