Numerical Simulation Of The Shell Semi-Solid Die Casting

Semi-solid casting which has nearly end forming, high efficiency and savingenergy. Semi-solid slurry viscosity, the filling smooth, not easy involved in gas; Solidphase ratio is high, can reach50%~60%, and solidified the narrow, casting has notprone to pore, shrinkage, mechanical performance is good. Into the die casting die heatsmall, to mold small thermal shock, can prolong the service life of the die. Semi-solidcasting solved the short life problem of high melting point alloy. Developed countrieshave met the extent of the commercial applications, our country is mainly applied inautomobile industry. But no matter in theory and technology, to further improve,especially in semi-solid casting technology and die design.Semi-solid die casting "shell" is not a stress, according to its deep space ofthin-walled structure, the gap type gating system has been used. On the surface forassembly of the threaded hole not directly cast out, after processing; Due to the possibleof internal pore and shrinkage defects, which requires the parts can’t have stoma defects,the demand is higher to the quality of the casting. According to the structurecharacteristics of the "shell", proceeding the analysis of the die casting technology andmold design.Using simulation software ProCAST simulates the "shell", according to the fillingprocess, solidification process, temperature distribution and shrinkage analysis, forecast,optimize the best process parameters: Injection speed5m/s, pouring temperature590C, mould preheating temperature220C. Semi-solid slurry flow smoothly in thewhole process, no splash, successive full of cavity, temperature distribution is balanced,porosity minimum, casting parts of the drilling without defect, can guarantee the qualityof castings.Electromagnetic stirring slurry making, through the observation of metallographicorganization, analysis, and concludes that get the parameters of the temperature and mixing time: Mixing current428A, frequency6Hz, under the condition of temperature590C, stirring time25min, most of the grain change into shape, boundary rounder,getting more ideal size of aluminum alloy. Mechanical mixing conditions: mixing10min, slurry temperature590Ctoo, for the best process parameters. Mechanicalagitation and electromagnetic stirring, size of the same temperature, electromagneticstirring the effect is good.Adopting the parameters of process optimization: the filling temperature590C,injection speed5m/s, die casting mould preheating temperature220C, Applicationof molding "shell" was tested, production of castings meet the technical requirements,processing to the parts of the threaded hole without stoma defects, which can producequalified casting.