Numerical Simulation And Technique Optimization Of The Permanent Casting Process On Aluminum Alloys Wheel-hub Used By Motorcycles

The permanent gravity casting process for the aluminum alloy motorcycle wheel-hub is simulated by ProCAST software in order to reduce the casting flaws, such as the shrinkage voids and rarefactions etc,increase the rates and properties of the finished products.The casting techniques are optimized,the production cycle is decrease,and the cost reduced.The main results are shown below:1.According to feeder and gate system theories,cast feeding principle and productive practical experience,the state of a permanent gravity casting process, distribution of place,size and shape of shrinkage porosity are studied,and the feeder's parameter is determined by means of the technique of computer numerical simulation, and the position relationship between feeder and shrinkage porosity is also discussed.2.The motorcycle wheel-hub marked LMC499-2 are simulated in permanent gravity casting filling and solidification process.The changing data for the flow field, temperature field and fraction of solid of the casting process are obtained,the shrinkage defects are preestimated,and the tests are carried out by examination producing.The casting technologies are optimized according to the simulation results and the practice producing.Temperature field in permanent gravity casting during casting process is adjusted by means of mold thermal insulating coating combining with localized cooling for mold and modification of bottom mold by analyzing the hot spot of the motorcycle wheel-hub,and then eliminated the hot spot of casting successfully.Thus,the thermal region between the spoke and rim are vanished,the shrinkage defects are avoided,and the order solidifications are obtained.3.Temperature distribution of mold in permanent gravity casting has been analyzed.The influences of natural cooling condition and force cooling condition have been investigated.The results showed that Temperature changed with the increase of casting cycles,the steady temperature gradient was founded inside casting mold in seven casting cycles,and then Heat balance of permanent mold was reached gradually.4.The effect with the addition of particle-reinforced to the casting property of metal-matrix composites is researched.The database of ProCAST is secondary developed basing on the function equation between the volume fraction of particle-reinforced and physical property parameter.Database of the metal-matrix composites physical property parameter is set.An motorcycle wheel-hub of an aluminum corporation is taken as study object to research the casting property of the 5%Al₂O₃/ZL101 particle-reinforcement aluminum matrix composites.The results indicate that the fluidity of the aluminum matrix composites tends to reduce because of the addition of particles.Melt viscosity of the composite is increased in evidence. Shrinkage porosity defect appears both in the spoke and rim of the wheel-hub.The content of Si is enhanced properly with the optimized casting techniques.So as to enhance the feeding capacity and fluidity of melt.The shrinkage porosity defect in the spoke and rim of the wheel-hub is decreased and eliminated.