InternshipSelf-Summary
Thefour-dayprehealwinternshipattheEngineeringTeagter(JuhtoJuh)waspletedstrictlyinaccordahtherotationscheduleoftheter,calltrainingmodulesincludingmaterialchemistryexperiments,traditionalhotandcoldprocessing,digitalnumericaltrolmaing,3Dprinting,aswelsspecialmaingsuchassercuttingandwireelectricaldischargemaing(WEDM).Theintensivepracticaltrainingmodewithalternatiionsaultipletradesallowedmetostepoutoftextbooktheoriespletely,andexperieheentiremeicalmanufacturingprocessfromrawmaterialf,cuttingmaing,specialmanufacturingtomaterialpropertytesting.Italsoeogainaprehensiveandihuandingoftherigorandpracticalityoftheengineeringmanufacturingindustry.
OnthefirstdayoftheinternshipwhenIfirstehetrainingworkshop,Iwasunfamiliarwithmostoftheequipmentandprocesses.Inthem,group-basedmaterialchemistryexperimentswerecarriedoutsimultaneouslywithrotationaltrainingincasting,serprocessing,3DprintingandCtheoperation.Duringmyfirstattemptatsandcastingmolding,Ifailedtotroltherammingforceproperlyandhahepartingsurfaceroughly,resultingiedproblemssuchasmoldcolpseduringpatterndrawingandcavitydefects.Wheihe,Iwasnotfamiliarwiththetoolsettinglogidmessedupthesettingoftoolpensationparameters,leadingtoseveredimensionalerrorsofpartsduringtrialoperation.Whengrindiallographicspesformaterialtesting,Iskippedgritgradesofabrasivepaper,leavingdeepscratchesonthespesurface,whichmadeitimpossibletodistinguishmetalmicrostructuresunderamicroscope.Ifeltoverwhelmedatfirstwhenfrohsuccessiveoperationalmistakes.Fortuhesupervisinginstructorsbrokedowntheoperatingstandardsstepbystep.Meanwhile,Irecordedkeyoperatingpointsanderror-proailsofeachtradeonthescheduleeveryday,reviewedthecausesofmistakesduringbreaks,andcorrectedmyoperatinghabitsbitbybit.
Astherotationproceeded,Isuccessivelygotinvolvedinwelding,f,wireelectricaldischargemaingandothertrades,eachofwhichbroughtnewdifficultiestotackle.Inthemanuarcweldingtraining,Ifrequentlyenteredimpropercurrentmatgaictravelspeedoftheweldingrod,causisincludingexcessivespatter,sginclusionandinpletepeiononweldingseams.Duringfpractice,Icouldnotaccuratelyjudgetheheatingtemperatures,andmymovementsfordrawingoutandupsettingwereuncoordinated,sothesizeandshapesfailedtomeetdrawingrequirements.Whendugwireelectricaldischargemaing,Ihadnoclearuandingoftheadjustmentlogiolybdenumwiretensionanddischargegappensatioinginobvioustaperandroughsurfathemaedparttours.Attheendofpracticaltrainingeveryafternoon,Isortedoutproblemsbasedonthedailyrotationtent,tooktheinitiativetosultteachersaboutproizationschemes,aedpracticaldrills.Gradually,Imasteredthecoreskillsofeachwprocedure:rammingsandevenlyinyersanddesigningreasogroovestoreduceblowholesandsandholesincasting;matgcurrentacctoptethiess,adoptingaunifzagtravelspeedandthhlyingweldingsgaftereachweldingpass;tensioningmolybdenumwiretightlybeforewirecuttingaingdischargepensationpreciselyacctoworkpiecethiesstogreatlyimprovemaingaccuracy.
Thefull-daytrainingonWednesdaycoveredf,wirecutting,group-wide3DprintingandcyclicpractiCthes,whereIalsoenteredvariousteicaldifficultiesin3Dprintiion.Initially,unreasonablesligparameterscausedproblemssuchasingatthebottomofprintedmodels,rgeinteryergapsandloosefilling.Byadjustinghotbedtemperature,redugtheprintingspeedofthefirstyerandoptimizingfilliy,togetherwithstandardizi-printingpolishingandsupportremovalprocedures,Ifinallyobtainedwell-formedmodelswithaccuratedimensionsandsmoothsurfaces.Materialchemistryexperimentsranthroughthefour-dayinternship.Afterrepeatedpracticeofthewholeworkflowincludingspecutting,roughandfinegrinding,polishig,metallographicmicroscopicobservationandhardesting,Itrulyuoodthecorretioweenthepositionandinterallographicstructureofmetalmaterialsandprocessingteologiessuchascasting,fandwelding.Irealizedthatdifferenthprocesseswouldgegrainmorphologyanddirectlyaffectservicepropertiesincludinghardnessandstrengthofparts.Aedengineeringthinkingthat"materialpropertiesdetermineprocessingteologies,andprocessingteologiesmodifymaterialperformances"wasestablishedinmymind,freeingmefromviewingmaterialexperimentsandmeicalprocessinginisotion.
Thursdaywasdesignatedforpreheationtrainingacrossalltrades,wherestudentsfromMaterialeandMaterialTwotookfulltrainingprojectscbenchwork,turning,milling,grinding,casting,f,welding,numericaltrolmaing,3Dprintitingandwirecutting.ItalsoservedasaprehensiveassessmentofwhatIhadlearhepreviousthreedays.Intraditionalcoldwtraining,filing,drillingandassemblyinbenchworkdemandedgreatpatiendprecisetrolofhandstrength.Myarmsachedafterlonghoursofmanualoperatiooedfilingandpolishingcouldguaranteeaccurateftnessofparts.Wheingmillingmaesandgrinders,feedrateandcuttingspeedhadtobestrictlytrolled;slightcarelessnesswouldleadtoscrappedworkpiecesduetoovercutting.Intheprogrammingsessionforingandmilling,Iattemptedtowritepletemaingprogramsforsteppedshaftsandgroovedparts.Iindepelyfihewholeprocessfrraminputandsingle-blocktrialruntotinuousautomaticmaing,andtrulyexperieheadvantagesofhighprecisionandhighefficybroughtbydigitalmanufacturing.Lasercuttingissuitableforrapidb
nkingofptes,3Dprintingexcelsinrapidprototypingofplexspecial-shapedstructures,andwirecuttingisappliedtotheprocessingoftinyprecisionparts.Variousdigitandspecialprocessingteologieshavetheirrespectivestrengthsandplementtraditionalhotandcoldprocessing,allowioclearlydistinguishtheapplicablesarios,advantagesanddisadvantagesofdifferentmanufacturingteologies.
Thefour-dayworkshoptrainingalsoimprongawarenessofprodusafetyinmymind.Persoeringtheworkshopmustwearborproteuniformsandsafetygoggles,withlonghairtieduptightly.High-temperatureoperationssuchascastingandfrequirestrictprecautionsagainstscalds;weldiionsmustbeequippedwithweldistopreventarclightburns.Beforestartingdcuttingequipment,protectivedevieedtobeied,andhandsmustneverapproachmovingposduringmaing.Circuitsandwatercircuitsshouldbecheckedbeforeoperatingspecialprocessingequipment,asanyviotionofoperatingrulesmaycauseequipmentdamageorpersonalinjury.Thesafetyspecifiphasizedbyinstructorsbeforeeachshift,aswelscasesofscrappedworkpiecescausedbyillegaloperationsIwitnessed,mademedeeplyrealizethatsafetyistheprimaryprerequisiteforallmeicalprodu,andstandardizedandrigorousoperatinghabitsarethemostfualliteracyfineeringpractitioners.
Whilegaininghands-onskillsandengineeringthinking,Ialsoclearlyidentifiedmanyshortingsofmyself.Firstofall,myabilityinmingisretivelyweak.Ilywritebasisforsimpleshaftparts,gprofiplexcystrusandmacrrams,andmyprocesspnningideasarelimitedwhenmaingspecial-shapedparts.Sedly,Ihaveinsuffitpracticalexperienfareatment.Itisdifficultformetojudgethepringtemperatureofmetalsbynakedeyes,andmyuandingofprocessesforimprovingmaterialpropertiessuchasgrainrefi,annealingandtemperingisnotthhenough.Thirdly,mytheoreticalfoundationofmaterialchemistryobestrengthened.Whenmetallographicstructures,Ilydistinguishbasicgrainfhly,failingtoaccuratelyanalyzehowprocessingteologiesaffectstructuralevolution.Fourthly,Iamdefitinoverallprocesspnning.Afterreceivingpartdrawings,Iotquicklyworkouttheoptimalprocessingsequence,whicheasilyleadstoreversedwproceduresandunreasonableallowancereservation.
Thismetalwinternshipfeaturedtightrotationsandhigh-iypracticaltrainingwithfrequentswitgbetweendifferenttradeseveryday.Althoughthewholeprocesswastough,IgairongsenseofaplishmeimeIindepelyproducedqualifiedcastings,weldingseams,high-precisionCpartsandclearmetallographicspes.Asanoldsayinggoes,"Whatyoulearnfrombooksisshallow;onlythroughpractiyougainthhuanding."Abstractmaingprinciplesandmaterialtheorieslearnedincssesbecameintuitiveaouandthroughfour