PbSnBi三元合金熔體溫度誘導(dǎo)液-液結(jié)構(gòu)轉(zhuǎn)變行為研究.pdf

1、分類號(hào)：!魚(yú)!!!!密級(jí)：——單位代碼：!!!i!學(xué)號(hào)D—311031—5035z奪肥工學(xué)火警HefeiUniversityofTechnology碩士學(xué)位論文MASTERDISSERTATIoN論文題目：PbSnBi三元合金熔體溫度誘導(dǎo)液一液學(xué)位類別：學(xué)科專業(yè)：(工程領(lǐng)域作者姓名：導(dǎo)師姓名：完成時(shí)間：結(jié)構(gòu)轉(zhuǎn)變行為研究學(xué)歷碩士ExplorationofTemperature—inducedLiquidliquidStructureTra

2、nsitionofPbSnBiternaryalloyABSTRACTLiquidliquidstructuralchangehasbecomeacommonconcerninliquidphysicstheseyears，whichenrichesthephenomenologyinliquidphysicsandshedlightonthestructureandpropertyofliquidmaterialsHowever，th

3、eessenceofthisphenomenonisstillseldomknownInordertostudytheadaptabilityoftemperature—induceddiscontinuousliquidstructuralchange，wecarryonallinvestigationofthetemperaturedependenceofelectricalresistivity(p—T)andstructurea

4、nalysisofliquidPbSnBialloyAsfollows，itismostcontentinthispaper：Firstwecarryonaresearchofelectricalresistivitycharacteristicwithtemperature，andfindtheelectricalresistivityofalloyhaveabnormalchangewithtemperature，comparedt

5、otheelectricalresistivityofpurePb，Sn，Bi，bythefourelectrodecontactmethod。Thischangeshowsthattherearetemperature—inducedliquid—liquiddiscontinuoustransitionsintheliquidalloySecond，theDSCisusedtoverifytheoccurrenceoftheallo

6、yliquid，liquidstructurechangefurther，theendothermicpeakontheDSCcurvealsoprovedtheexistenceofliquid—liquidstructurechangeduringtheperiodofheatingcontinuouslyThereasonofthatchangeisthepreviousbondsandlocalshort—rangeorders

7、whicharederivedformsolidstatearebrokentoformnewbondsordissolvetomakethehightemperatureliquidmoredisorderAtthesame，thecredibilityoffourelectrodecontactmethodisalsoprovedThird，itisalsofoundthatthereareliquid—liquidtransiti

8、onsduringcoolingprocess，butwefinditisonlyreversibilityforthesecondorlaterhotcirculationTheconcretereasonofthiskindofphenomenonmaybebecausetheinteractionsofthespecialatomsinthesecompositionorganizationswhichmakeitspropert

9、yspecial，sothestructurechangesremainexistinthecoolingprocessFourth，thesolidificationbehaviorandmicrostructureofPbSnBialloyareinvestigatedItisfoundthatsolidificationundercoolingdegreeincreasesgreatlyafterliquidstructurech

10、angeandthesolidificationstructurebecomesfinerevidentlyTheresultshowsthattemperatureinduceddiscontinuousliquidstructuralchangeaffectsthesolidificationbehaviorandmicrostructureremarkably，Keywords：Liquidstructure，Electrical