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铝合金的熔炼与铸造(Meltingandcastingofaluminumalloy) Meltingandcasting Meltingandpouringofaluminumalloyisthemainlinkin castingproduction.Thewholeprocessofmeltingandcasting isstrictlycontrolled,whichplaysanimportantrolein preventingcastingdefectssuchaspinholes,inclusions, castings,cracks,porosityandshrinkage.Becausethealuminum meltabsorbsthehydrogentendency,theoxidationabilityis strong,dissolvestheironeasily,insmeltingandthecasting process,musttakethesimpleandcarefulpreventivemeasure, obtainsthehigh-qualitycasting. 1、preparationandqualitycontrolofaluminumalloyburden Inordertosmelthighqualityaluminummelt,thequalifiedraw materialshouldbeselectedfirst.Tocarryoutscientific managementandproperprocessingofrawmaterials,otherwise itwillseriouslyaffectthequalityofthealloy,the productionpracticehasprovedthattherawmaterials (includingmetalmaterialsandauxiliarymaterials)lax controlwillmakebatchscrapcastings. (1)rawmaterialsmusthavequalifiedchemicalcompositionand organization,andthespecificrequirementsareasfollows: Inadditiontotheanalysisofthemaincomponentsand impuritiesinthealloyingots,themicrostructureandfracture ofthealloywereexamined.Practicehasprovedthattheuse ofseriousshrinkagecavity,pinhole,andbubblesofaluminum liquid,itisdifficulttoobtaindensecastings,andevencause thewholefurnace,batchcastingsscrapped. ItwasfoundinthestudyofAlSialloyingotsofAluminumAlloy pinhole,doesnotappearinthemoltenpuresandcastingpinhole testblock,whenthealuminumsiliconalloyingotwithlowand unqualifiedspecimens,pinholeserious,andthegrainsize large.Thereasonistheheredityofthematerial.Theheredity ofAlSialloyandheredityincreasedwiththeincreaseof contentandtheamountofsiliconreached7%.Continueto increasesiliconcontenttoeutecticcomponent,heredity decreasesslightlyagain.Inordertosolvethecastingdefects causedbytheheredityoftheburden,aluminumingots, intermediatealloysandotherchargingmaterialswithhigh metallurgicalqualitymustbeselected.Specificstandardsare asfollows: (1)thereshouldbenopinholesorholesinthefractur