| Magnesium alloy,as the lightest metal structural material in the field of engineering technology,has been used in aerospace,automotive,3C and other fields for many years,but its poor corrosion resistance limits its huge market space.The aluminum alloy with good corrosion resistance and processing performance is used to coat the outside of the magnesium alloy,and the obtained aluminum-magnesium bimetallic composite material has good corrosion resistance and can improve the processing and forming ability.This aluminum-magnesium double-layer composite material has the advantages of magnesium alloy light weight and aluminum alloy corrosion resistance.Through the method of aluminum-magnesium solid-liquid die forging connection,various structural components can be manufactured,which will be used in automobile manufacturing,There is more and more room for development in the fields of electronics and aerospace.In this paper,AZ91D magnesium alloy and AA6061 aluminum alloy are used as materials to carry out the research of aluminum-magnesium bimetallic composite materials.The main content includes the numerical simulation of AA6061-AZ91D aluminum-magnesium bimetallic tees;aluminum-magnesium bimetallic foundation connection experiment and its microstructure Analysis of mechanical properties;forming aluminum-magnesium bimetallic tee under better process parameters.This article first uses Deform-3D numerical simulation software to simulate the forming process of aluminum-magnesium bimetallic tees under different process parameters,and analyzes the equivalent stress,equivalent strain and temperature field changes of the aluminum-magnesium bimetal at the end of forming.The loading speed of the upper mold has the greatest influence on the forming process of the aluminum-magnesium bimetallic tee;the temperature of the blank and the temperature of the upper and lower molds are the second;the friction coefficient has little influence.In this experiment,the aluminum-magnesium bimetallic basic connection experiment was carried out with different heating temperature,holding time and reduction,and the microstructure evolution law and mechanical properties of the aluminum-magnesium bimetallic sample were analyzed.The bonding interface is mainly divided into three layers,Respectively are the aluminum side near the I area(the connection interface is close to the AA6061 aluminum alloy side),the phase composition is mainly Al3Mg2;the II area is a stable diffusion layer,and the phase composition is mainly Al12Mg17;the III area is near the magnesium side(the connection interface is close to the AZ91D magnesium Alloy side),the phase composition is mainly ?-Mg+Al12Mg17,in addition,there is a small amount of Al Mg phase at the junction of zone I(near the aluminum side)and zone II(stable diffusion layer);the microstructure at the side branch of the aluminum-magnesium bimetallic tee This law is basically present.The mechanical properties of the aluminum-magnesium bimetallic base connection specimens were analyzed,and it was found that the aluminum alloy inner surface and the magnesium alloy of the specimens with different parameters at 610? and 620? were connected between the inner surface of the aluminum alloy and the magnesium alloy,but the main mechanical connection was the diffusion connection.As a supplement,most of them are concentrated between 3-4 MPa,and the connection strength is low.The shear strength of the sample with 30% reduction at 610? for 40 minutes is the highest,which is 6.60 MPa;the formed aluminum-magnesium bimetallic tee has poor mechanical properties,and the bonding interface is mainly mechanical connection.Some parameters are as follows: A low degree of diffusion connection is realized at the side branch pipe of the through piece,and the shear strength is 10.58 MPa. |
PDF Full Text Request