1、Vol.2 No.1,Feb.2005CHINA FOUNDRYDie design and process optimization of die cast V6engine blocks*Henry HU1,Yeouli CHU2,Patrick CHENG2(1.Department of Mechanical,Automotive&Materials Engineering University of Windsor;2.Research and DevelopmentRyobi Die Casting(USA),Inc.)Abstract:The use of aluminum,pa
2、rticularly for engine blocks,has grown considerably in the past ten years,andcontinues to rise in the automotive industry.In order to enhance the quality and engineering functionality of die castengine blocks,die design and processes have to be optimized.In this study,a computer simulation software,
3、MAGMAsoft,as an advanced tool for optimizing die design and casting process,was employed to virtually visualize cavityfilling and patterns of a V6 engine block.The original die design and process was simulated first to establish a baseline.A reality check was used to verify the predicted results.The
4、n,the die modification with a different runner system wasmade by using a CAD software,Unigraphics(UG).The simulation on combinations of the modified die design andrevised process was performed to examine the effect of die modification and process change on flow filling of V6 engineblocks.The simulat
5、ed prediction indicates that the enhancement of cavity filling due to the die and process modificationminimizes the occurrence of defects during casting,and consequently improves the quality of blocks.The results ofmechanical testing show a significant increase in fatigue strengths,and a moderately
6、improvement on tensile propertiesfor the blocks die cast with the new die design and process in comparison with those produced by the original ones.Keywords:die design;simulation;engine blocksCLC number:TG292-39 Document:A Article ID:1672-6421(2005)01-0021-071.IntroductionDue to fuel economy and emi
7、ssion pressures,the use ofaluminum continues to rise in the automotive industry.Aluminums use in automobiles worldwide has gone from45 kg(101 lbs)in the 1970s to more than 100 kg(225 lbs)today,and will top 150 kg(337 lbs)per vehicle by 2010.Over the past 10 years,shipments of aluminum castingsincrea
8、sed by nearly 65%.Aluminum casting weight pervehicles is also forecast to grow to 123 kg(270 lbs)by2011 1.The major impetus behind more widespreadaluminum casting use has been the auto industrys fueleconomy requirements,which have necessitated the trendtoward lighter cars and trucks.This is because
9、up to eightpercent fuel savings or as much as 2.5 extra miles pergallon can be realized for every 10 percent reduction inweight from substituting aluminum for heavier metals.Asa result,a vehicle that uses less fuel by lowering its weightwith aluminum produces fewer greenhouse gas emissions.It is for
10、ecast that the use of aluminum for car and lightvehicle engine block applications is expected to explodeby 48%over the next 10 years.As one of Wards 10 bestengines for 1999 2,General Motor Corps aluminum-intensified 3.5-liter V6 engines was introduced in 1998.This paper discusses development work in
11、volved inprototyping and production of die cast aluminum blocksfor V6 engines.During V6 block development,variousversions of die design and process parameters wereinvestigated.The original gating system and processdesign was a combination of L-runner and slow filling asshown in Fig.1.The disadvantag
12、es of L-runner design andslow filling process during the production have beenfound,which result in various defects such as Siamesecracks,cold shuts and porosity-related leak.In order to overcome the disadvantages of the old dieand process design,extensive computer simulation workwas conducted to ana
13、lyze the cavity filling sequences andtemperature distribution with different gate designs andprocess parameters.The goal has been to prevent andminimize the occurrence of defects,and enhance thequality and engineering functionality of V6 blocks.A flowand thermal modeling software,MAGMAsoft 3-4,wasem
14、ployed for the simulation work while a CAD software,Unigraphics,was used for the modification of die design.In this paper,the simulation results for the cavity filling ofthe aluminum V6 blocks are presented.The numericalsimulation was validated by a reality check with a partialfilled V6 block.The me
15、rits and demerits of different gatedesign and process parameters are discussed.Theverification of simulation was carried out by mechanically*Henry HU:Associate Prof.,research is focused on transportphenomena and mechanisms of solidification,phase transformation and dissolution kinetics.E-mail:huhuwi
16、ndsor.caReceived date 2004-09-01;Accepted date 2004-12-04CHINA FOUNDRYFeb.2005testing specimens sampled from the bulkhead region ofblocks to determine their fatigue strengths and tensileproperties.2.Simulation and mechanical testingprocedures2.1 Geometry modeling and simulationSimulation of the cavity filling and solidificationprocess requires the geometry input of the casting and thedie,including the internal cooling system.Fig.2 showsthe solid CAD model created with UG of Unigraphicssolution I
