內(nèi)生塑性相形態(tài)演化及其對塊體金屬玻璃復(fù)合材料力學(xué)行為的影響.pdf

1、南京理工大學(xué)碩士學(xué)位論文內(nèi)生塑性相形態(tài)演化及其對塊體金屬玻璃復(fù)合材料力學(xué)行為的影響姓名：徐翔申請學(xué)位級別：碩士專業(yè)：材料學(xué)指導(dǎo)教師：陳光張中武20090601碩1：論文內(nèi)生塑性相形態(tài)演化及其對塊體會屬玻璃復(fù)合材料力學(xué)行為的影響AbstractBulkmetallicglass(BMG)possessesaseriesofexcellentproperties，suchashi【曲strengthandhardness，corrosion

2、resistanceandexcellentmagneticpropertiesHowevertheapplicationofBMGisrestrictedseverelybyroomtemperaturebrittlenessTheinnovationofBMGcompositeswithductilecrystallineparticlesCanimprovetheroomtemperatureductilityTheductili

3、tyofthisl【indofcompositeisinfluenceddramaticallybytheductilecrystallineprecipitates，especiallythemorphologysize，distribution，volumefractionandetcInthepresentwork，Zr60Til467Nb533Cu556Ni4a4Bel0Wasusedtoinvestigatetheeffect

4、sofprocessingparametersonthemicrostructureevolutionofinsituductilephaseandconsequentlyonthemechanicalbehaviorofBMGcompositeswithinsitupZr(Ti，Nb)crystallinephaseAndthenthecorrespondingmechanismswerediscussedTheeffectsofho

5、ldingtimeunderafixedtemperatureontheevolutionofinsitu8phaseinBMGcomposites，especiallytheevolutionfromdendritictospheroidal，andtheireffectsonmechanicalbehaviorwereinvestigatedsystematicallyTheresultsshowthatboththemicrost

6、ructuresandmechanicalbehaviorareinfluencedsignificantlybytheholdingtimeThesizeofflphaseincreasesandthemorphologyofflphasechangesfromdendritictospheroidalgraduallywithprolongingtheholdingtimewhilethevolumefractionof8phase

7、donotchangeobviouslymaintainingapproximately50％Howeverwhentheholdingtimeisprolongedto20min，the|Bphasereachesastablestate，andthesizeandmorphologyof9phasehavenolongerobviouschangewithprolongingtheholdingtimeThisphenomenawa

8、sexplainedbasedonthediffusiontheoryofcurvedinterfaceinamultiphasesystemThereisasimilarchangeofthemechanicalpropertywitlltheevolutionofinsituductilephaseTheplasticstrainincreaseswithprolongingtheholdingtimeandalseachesast

9、ablevalueTheeffectofcoolingrateonthemierostructureevolutionofinsituductilecrystallineinclusionsanditseffectonthemechanicalpropertieswerealsoinvestigatedsystematicallyTheresultsshowthatonlydendriticlikeinsitu∥phasec齟beobt

10、ainedinourstudiesHoweverwiththedecreasingofcoolingrate，thesizeandvolumefractionofinsitu8phaseincreaseandthemorphologytransformsfromfinetocoatdedendriticWhenthewithdrawingratedecreasestolmm／s，anewintermetallicphaseoc螂Mean