Chapter11Metal-CastingProcessesContent11.10SlushCasting凝壳铸造11.11PressureCasting压力铸造11.12DieCasting压模铸造11.13CentrifugalCasting离心铸造11.14SqueezeCastingandSemisolid-MetalCasting积压铸造和半固态金属成型11.15CastingTechniquesforSingle-Crystalcomponents单晶零件的铸造技术11.16RapidSolidification(AmorphousAlloys)快速凝固（非晶和金）11.17InspectionofCastings铸件检验11.18MeltingPracticeandFurnaces熔化操作和熔炉11.19FoundriesandFoundryAutomation铸造厂与铸造自动化11.1IntroductionProcessTwotrendsarecurrentlyhavingamajorimpactonthecastingindustry.Thefirstiscontinuingmechanizationandautomationofthecastingprocess,whichhasledtosignificantchangesintheuseofequipmentandlabor.Advancedmachineryandautomatedprocess-controlsystemshavereplacedtraditionalmethodsofcasting.Thesecondistheincreasingdemandforhigh-qualitycastingswithclosedimensionaltolerances（容许尺寸公差）andnodefects（Fig.11.2）.当前有两个趋势对铸造工业起重要冲击作用。第一个是正在持续进行的铸造过程机械化和自动化，它导致铸造设备和劳动力方面发生重大变化。先进的机械和自动的过程控制系统已经取代了传统的铸造方法。第二个是对具有严格尺寸公差和五缺陷的高质量铸件的需求正在增长（表11.2）。ProcessExpendablemolds（一次性模）,madeofsand,plaster,ceramicandsimilarmaterials,usedjustonetime,shownin11.2-11.8.Permanentmold（永久性模）,usedmanytime,shownin11.9-11.14;Compositemold（复合模）,madebytwodifferentmaterialsinordertogetdesiredproperties.11.2SANDCASTINGFig.11.5Outline(草图)ofproductionstepsinatypicalsand-castingoperation11.2.1Sands11.2.2TypesofSandMoldsCold-boxedmoldprocess,variousorganic(有机的)andinorganic(无机的)binders(粘结剂)areblended(混合)intothesandtobondthegrainschemicallyforgreaterstrength,moredimensionalaccuracy,butmoreexpensivecomparedwithgreen-sandmold.No-bakemoldprocess,mixedwithsynthetic(合成的)liquidresin(树脂),Hardingbyself,calledcold-settingprocesses.Fig.11.4Schematicillustration（示意图）ofasandmold,showingvariousfeatures（性质、特点）.11.2.3Patterns(模型)Becausepatternsareusedrepeatedlytomakemolds,thestrengthanddurability(持久性)ofthematerialselectedforpatternsmustreflectthenumberofcastingsthatthemoldwillproduce.Theymaybemadeofacombinationofmaterialstoreducewearincriticalregions.Patternsareusuallycoatedwithapartingagent(脱模剂，分型剂)tofacilitatethei