Study On Casting Process Of Aluminium Alloy Impeller

Automotive turbochargers have advantages of high efficiency, environmentalprotection, energy saving and lower consumption. It is already widely used in gasolineand diesel engines. Impeller is rotating in high temperature and high pressureenvironment. It is one of the components that are prone to failure. Impeller prone tohave shrinkage porosity, shrinkage hole, subsurface blowhole, misran and other defects.This will reduce its yield and working life. Reasonable casting process can reducesdefects effectively. But it takes a long time through experiences and tried castingmethod.A certain type of impeller’s process conditions was researched，materials for theZL105A alloy, quality700g, wheel diameter99mm, blade number14, thickness0.5mm~3mm. Mold design and casting process difficult. This paper uses three coordinatemeasuring machine in combination with UG software, get an accuratethree-dimensional map of the impeller.Analysis of low pressure die casting process, determining parting surfaces, designstock chart and figure dies. ProCAST simulation software, depending on the State ofmolten aluminum filling and venting, adjust the pressure-time curve, resulting inpressure-time parameter is: filling0.01MPa,1s; booster0.05MPa,4s; keeping0.05Mpa,120s; relief4s; according to the casting shrinkage porosity volume fraction,pouring temperature, plaster mold and chill temperatures orthogonal numericalsimulation. Results: the pouring temperature680°C, plaster mold temperature225°C,cold iron temperature175°C.On water filling stage of low pressure casting, the water simulation indicates that,water of filling type State and numerical simulation of results similar, early relativesmooth, late is raised of fountain shaped; boost rate more big, filling type time moreshort, due to back pressure of increases, filling type time appeared delay; due to water simulation of mold in points type surface cannot exhaust,。Filling type time is longerthan the time of numerical simulation.Gravity Foundry technique analysis of impeller design rough diagram and figuredies, ProCAST pouring temperature, casting speeds, mould temperature simulationexperiment with three factors, optimal parameter is: pouring temperature of730°C,gypsum mold preheat temperature225°C, cold iron temperature of175°C, pouringspeed0.3m/s.Through a water simulation, numerical simulation of water flow with consistent,both volume and bubbles; due to the water to simulate the actual gate area is relativelysmall, pouring over a long time.Process parameters obtained by the factory small batch verification, low pressurecasting process yield was95%higher position, gravity casting process was60%,indicating a reasonable optimized process parameters.