Experimental Research On Solid-liquid Forming Mechanism Of Invar/Cu Bimetal Clad Plate

Using composite technology to combine several kinds of metal components together and promoting them to combine firmly at the interface,layered mental composites materials synthesize the advantage of all components,creating new-metal materials,which are widely used in aerospace,Power electronic,chemical industry,shipbuilding and automobile fields.The bonding mechanism of Invar/Cu interface in the composite area of the cast-rolling is the main research object in the paper.Based on liquid-solid bimetal the compound-casting and cast-rolling composite process,the experimental scheme is designed to realize the composite of the invar alloy and copper,and its composite interface is observed and the mechanical properties are tested.Changing the diffusion temperature and the solid-liquid action time and Developing the experiment of liquid-solid bimetal compound-casting gets Invar/Cu clad plate under 1200?.After annealing of the part of the clad plate,the SEM and EDS scanning are analyzed,and the results show that the annealing temperature is 600?,700?,800?and the insulation time is 2h,the interfacial diffusion layer thickness is 0.5 ?m,0.8 ?m and 0.9 ?m.Annealing temperature for 800 ? and the insulation time for 0.5h,1h and 2h,the diffusion layer thickness is 0.5 ?m,0.7?m and 0.9 ?m.It shows that the annealing temperature and prolonging the insulation time are beneficial to the mutual diffusion of metal elements near the interface and the increaser of the thickness of the diffusion layer.To explore Invar/Cu with solid-liquid casting forming technology of composite,with Fluent software established a steady cast-rolling process of two-dimensional heat-flow coupling model,research and casting speed,invar alloy preheating temperature,invar alloy strip thickness,copper pouring temperature parameters on the casting temperature field and flow field distribution.The results show that,improving casting speed and the preheating temperature of invar alloy,increasing the thickness of the invar alloy strip can effectively increase the temperature of composite interface and liquid region.Meanwhile,increasing the pouring temperature of molten copper can improve flow condition of the liquid metal in cast rolling region.Based on the numerical simulation,this paper researched solid-liquid casting combined rolling forming process of the Invar/Cu clad plate,and manufactured Invar/Cu clad plate of 3mm,under the casting speed of 2m/min,copper liquid pouring temperature of 1170?,pool height of 30 mm,invar alloy thickness of 0.6mm,and temperature of 25?.Tensile strength of cast-rolled clad plate is 250 MPa.Peel strength for an average is 13.85N/mm,clad plate average peeling strength of annealed is 42.31N/mm at 800 ? annealing heat preservation for 1 hour.The results of tensile,bending and stripping showed that Invar/Cu clad plate had good interface quality,with good mechanical coordination;the analysis of SEM and EDS showed that the fracture location occurs on the copper matrix,and the fracture dimple is obvious.In order to explore the bonding mechanism of the Invar/Cu composite casting plate,using the urgent stopping method to intercept the specimen in the solid-liquid casting and rolling compound area,the interface of the SEM and EDS analysis,the results show that the temperature and pressure are two key factors influencing the interfacial composite quality.In the area above the Kiss point,the copper metal melt and the alloy strip surface contact heat transfer and solidification coated with the alloy belt surface,formed the initial physical nion state,because the tile alloy and the copper spread to each other under the high temperature drive,form 2?m thick diffusion layer,and then under continuous pressure deformation,the effect is thinned to 1.6?m.