zrolt2gt增强zr基大块非晶复合材料制备工艺探索及其力学性能研究

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1、摘要ZrO2增强Zr基大块非晶复合材料制备工艺探索及其力学性能研究摘要本文以Cu46Zr42Al7Y5和Zr55Cu30Al10Ni5块体金属玻璃为基体，10µmZrO2颗粒为增强体，尝试采用铜模铸造法和粉末热压成型法制备ZrO2/Zr基大块非晶复合材料，研究了复合材料的压缩力学性能。研究表明，用铜模铸造法制备ZrO2/Cu46Zr42Al7Y5非晶复合材料时，ZrO2会在复合锭熔炼过程中与Y元素发生置换反应，最后制备得到的是Y2O3/Zr-Cu-Al-Y非晶复合材料。复合材料的压缩断裂强度因Y2O3颗粒的增强作用和非晶基体成分的改变而得到提高。用铜模铸造法制备ZrO2/Z

2、r55Cu30Al10Ni5非晶复合材料时，复合材料中会出现淬态晶化相。分析原因是ZrO2颗粒吸附的氧诱发了非晶基体晶化相的析出，提高了非晶形成的临界冷却速度，同时减小了非晶合金的过冷液相区的大小，降低了非晶复合材料的热稳定性。复合材料的断裂由韧性断裂转变为脆性断裂，但压缩断裂强度随着ZrO2含量的增加而得到提高。采用粉末热压成型法可以成功制备出ZrO2/Zr基大块非晶复合材料。这种制备方法减弱了ZrO2与Y元素的反应，降低了非晶基体对ZrO2吸附氧的敏感性，在制备ZrO2/Zr基大块非晶复合材料上比铜模铸造法具备更大的优势。关键词：ZrO2/Zr基块体非晶复合材料，铜模铸

3、造，粉末热压成型，力学性能I摘要TheSynthesisofZrO2/Zr-BasedBulkMetallicGlassCompositesandStudyofTheirMechanicalPropertiesAbstractByusingtechniquesofcoppermoldcastingandpowderhot-pressedforming,ZrO2/Zr-basedbulkmetallicglass(BMG)compositeshavebeenfabricated,andthemechanicalpropertiesofZrO2/Zr-basedBMGcompo

4、siteshavebeenstudiedinthispaper.TheparticleofZrO2wouldreactwiththeelementYwhenthearcmeltingtechniquewasusedtoprepareZrO2/Cu46Zr42Al7Y5compositeingot.Asaresult,thestructureofthecompositeaftercoppermoldcastingwasamorphousmatrixreinforcedbyY2O3particles.Thecompressivefailurestrengthofthecompo

5、sitesincreasedbecauseofthereinforcementofY2O3particlesandthecompositionalvariationoftheamorphousmatrix.TheZrO2/Zr55Cu30Al10Ni5BMGcompositespreparedbycoppermoldcastingcontainedsomequenched-incrystallinephase,becausetheoxygeninducedbytheZrO2particlesincreasedthecriticalcoolingratebyinducingc

6、rystallineprecipitationandhencenarrowingsupercooledliquidregionanddecreasingthethermalstabilityofthemetallicglasscomposites.ThemodeoffracturechangedfromductiletofragilefortheBMGcomposites,butthecompressivefailurestrengthincreased.TheZrO2/Zr-basedBMGcompositesweresuccessfullypreparedbypowde

7、rhot-pressedformingmethod,sinceitweakenedthereactionbetweenZrO2andelementY,andreducedthesensibilityofoxygenfortheamorphousmatrix.Themethodofhot-pressedformingexhibitsmoreadvantagesinpreparingZrO2/Zr-basedbulkmetallicglasscompositesthancoppermoldcasting.Keyword