Microstructure And Property Of A380 Alloy And Technology Of Rod Parts Prepared By Squeeze Casting

In this paper,the microstructure and properties of A380 aluminum alloy were studied under the condition of liquid die forging,and the technical scheme for the preparation of liquid forging rod parts was developed.Firstly,comparing the A3 80 microstructure and property under different pressure,to obtain the optimal pressure value;By comparing the microstructure and properties of A3 80 with different rare earth Ce addition,the optimal addition amount was obtained.Secondly,the optimal parameters of A380 were used in squeeze casting technology development of rod automotive parts.Process scheme and mold design of A380 control arm were launched.Also,the material and process scheme of squeeze casting control arm were determined.The microstructures and mechanical properties of A380 alloy solidified at different squeeze pressures were investigated.The obtained results showed that compared with the gravity casting specimens,the porosity decreases,the microstructure is refined and the mechanical properties are improved obviously.When the squeeze pressure was increased from 0 MPa to 75MPa in the squeeze casting process,the size of dendrite arm and the porosity was decreased;the eutectic volume fraction of specimen was increased;the secondary dendrite spacing was decreased;the size of needle-like ?-Al5FeSi phase decreased significantly,and a few Chinese script a-Alg(Fe,Mn)3Si2 phases was observed in the grain boundary.When the pressure increases in the range of 75?100 MPa,the effect of pressure on the microstructure refinement,the second phase morphology and the mechanical properties of the alloy is not obvious.Therefore,the optimal pressure value is 75Mpa.When the squeeze pressure was 75MPa,the tensile strength and elongation of the A3 80 alloy were increased by 19%and 65%respectively compared with the gravity casting.In order to further ameliorate the microstructure and property of squeeze casting alloy A380,a series experiments had been conducted under the same pressure to explore the rare earth Ce content's influence.The results showed that with the increase of Ce content,grain size decreased,eutectic Si from coarse needle into small,intermittent,dispersion of short rods and granular,the rough acicular morphology phase in Fe was improved,which changed into fibrous small scale,volume fraction also fell sharply.When the Ce content>0.5%,the rare earth compounds Al8Cu4Ce was forming between grain boundary.The Brinell hardness,tensile strength and impact toughness of the alloy were improved with the increase of the content of rare earth,which showed the best performance at 0.5%.To improve the preparation of A380 aluminum alloy for the straight shank-front suspension control arm,the liquid forging drawings was mapped,the liquid forging method,the key position and liquid forging process parameters of forming method were determined;combined with the process,the function of the corresponding equipment design,and technical design was given.Combined with the process and equipment of liquid forging,the forging mold was designed,including the overall structure of the mold,the key components,,as well as mold verification,filling simulation.The technology solutions of production and the function of liquid forging equipment were obtained in order to provide the comprehensive technical support for the liquid forging A380 parts.