Study On The Microstructure And Properties Of Al-Cu Alloys Castings Formed By Direct Squeeze Casting And Heat Treatment

In the field of equip and manufacture industry，for the sake of economizing materialand reducing energy sources depletion，tightening the weight of components is the targetthat the people pursue over a long period of time，is also one of development trend ofmodem manufacturing technique．The lightweighting can be realized by adopting lightmetal or higher strength material．The stengthen and toughening of Al alloy colligate theway of lightweighting．In the experiment，via the ZL205A alloy casting formed by directsqueeze casting．Study on the effects on the casts mechanical properties and microstructureof direct squeeze casting process parameter，cryogenic treatment and heat treatment. Atlast，verify the ZL205A alloy used in the serpentine shock absorber of corbel CRH7feasibility．The main parameter on direct squeeze casting process are the intensity of pressure、thepouring temperature、the mold temperature、the time of pressure holding etc. Test resultsshow that the values of optimal process parameters are that the intensity of pressure is120MPa，the pouring temperature is760℃，the mold temperature is210℃，and the timeof pressure holding is22s．The intensity of pressure is significant influence factors oncasting mechanical properties and microstructure，the mechanical properties of squeezedcastings relative to the metal mold casting mechanical properties have been improvedgreatly，tensile strength and elongation are improved significantly．When extrusionpressure is120MPa，pouring temperature is760℃，alloy tensile strength is238.6MPa，elongation is9.2%．This paper also studies the ZL205A solid solution treatment，solid solution and agingtreatment，solid solution deepen cold plus aging treatment on mechanical properties ofcastings，when solid solution treatment parameters is (538℃×10h)，alloy tensile strength is381.2MPa，elongation is11.6%，Solid solution treatment by aging treatment after castingits mechanical performance has been improved to some extent，when solid solution treatment parameters for (538℃×10h) and aging treatment parameters for (175℃×6h)，alloy tensile strength is468.6MPa，elongation is8.6%；Solution processed by cryogenictreatment casting time effect learning performance has been improved to some extent，when solid solution treatment parameters for (538℃×10h) deepen cold treatmentparameters for (-196℃×24h) plus aging treatment parameters for (175℃×6h)，alloy tensilestrength is489.9MPa，elongation is11.3%．High iron CRH7corbel serpentine shock absorber simulation operation resultsmaximum stress strength is298.6MPa，the ZL205A alloy after heat treatment to meet therequirements of its mechanical properties．...