简介:ThehotdeformationbehaviorofextrudedAZ80magnesiumalloywasinvestigatedusingcompressiontestsinthetemperaturerangeof250-400℃andstrainraterangeof0.001-1.000s^-1.The3Dpowerdissipationmapwasdevelopedtoevaluatethehotdeformationmechanismsanddeterminetheoptimalprocessingparameters.Twodomainsofdynamicrecrystallizationwereidentifiedfromthe3Dpowerdissipationmap,
简介:Inthispaper,themicrostructureandhardnessofHG980Dheat-affectedzone(HAZ)atdifferentcoolingratet8/3werestudied,theimplantcriticalfracturestressunderthreediffusiblehydrogenconditionsweremeasured,andthehydrogen-inducedcracking(HIC)fractographofsteelHG980Dwereanalyzed.TheexperimentalresultsshowthatmartensiteexistsinHAZofHG980Dtillt8/3≥150s,thehardenquenchingtendencyofHG980Disgreater;Theimplantcriticalfracturestressisrelatedtodiffusiblehydrogencontentsignificantly,atlowhydrogenlevel,highrestraintstressisneededtonucleateHIC,thefractographismainlymicrovoidcoalescence,butathighhydrogenlevel,onlysmallrestraintstresscancauseHICoccurrence,thefractographismainlyquasicleavage.Itisveryimportanttochooseultra-lowhydrogenweldingconsumabletoweldsteelHG980Dtopreventhydrogen-inducedcracking.
简介:Microstructuresandmechanicalpropertiesoftransientliquidphase(TLP)bondedmagnesiummetalmatrixcomposite(MMC)jointsusingcopperinterlayerhavebeeninvestigated.Withanincreaseofbondingtimesfrom5minto50minatbondingtemperatureof510℃,theaverageconcentrationofcopperinthebondedzonedecreased,themicrostructureinthezonechangedfromCu,α-MgandCuMg2toα-Mg,CuMg2andTiC,andmechanicalpropertiesofthejointincreased.Theshearstrengthofthejointbondedat510℃for50minreached64MPaduetothemetallurgicalbondingofthejointandimprovingitshomogeneityofcompositionandmicrostructure.ItisfavorabletoincreasethebondingtimeforimprovingmechanicalpropertiesofTLPbondedmagnesiumMMCjoint.