zr含量对ti-25nb合金组织和弹性性能的影响

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1、摘要本文采用高真空非自耗电弧熔炼炉制备钛锆铌合金，进行热锻、正火、冷轧及退火等处理过程。通过差热分析、金相组织观察、X射线衍射、显微硬度测定、晶格参数计算以及弯曲测试等方法分析了不同Zr含量的钛铌基合金组织和结构，并对其弹性性能做出了检测与评价。研究结果表明：该系列钛合金基体为6相，晶粒中有少量针状c【相析出，在晶界处也会有球状Ⅱ相偏聚。Zr元素添加对钛合金a／13相转变温度产生一定影响，随着Zr含量的增加转变温度升高。zr元素的添加使得均匀化后合金的晶粒逐渐细化，有助于提高合金的机械性能。在均匀化态和热锻态合金中，随着Zr元素的加入，合金硬度先降低后升高，3at％Zr时达到最低值。

2、均匀化、热锻、正火三种状态下的合金硬度中，均匀化态最高，热锻处理后降低，正火处理后硬度变化不大。随着Zr含量的增加，点阵参数逐渐变大。均匀化合金点阵参数最大，随着热锻和正火处理，合金缺陷减少，结构更加稳定，点阵参数也逐渐减小。Zr元素含量为3at％时，弹性回复性能较好。一般情况下，随着退火温度的升高，该系列合金的弹性【旦

3、复能力越好。但Zr元素含量为3at％时出现异常，与此成分合金的Ms点略低于室温有关。关键词：钛合金；超弹性；生物医用材料ABSTRACTInthispapentheTi··Zr-·Nballoyswerepreparedusingnon—-consumablearc

4、meltingfurnace，andthenprocessedbyhot—forging，normalizingtreatment，cold-rollingandannealing．ThealloyswithdifferentamountofZraddedwereinvestigatedbyDSC，microstructureobservation，XRD，micro—hardnesstesting，calculationofthelatticeparametersandbendingtest，thentheirelasticperformancewasmeasuredandeval

5、uated．Theresultsindicatedthatthealloysexploitedwerecomposedofa13-phasematrixandsomeneedle—shapeda—phaseprecipitationwithsameball-shapeda-phasesegregationatgraininterface．TheaddictionofZrelementinfluencedthe0113transformationtemperature．TheZrelementcouldfinethegrainsofthealloysafterhomogenizing，

6、consequentlyenhancingthemechanicsproperties．Atthehomogenizingstateandthehot—rollingstate，thehardnessofthealloysdecreasedfirstlyandincreasedlastlyalongwiththeadditionofZr,withaminimumat3at％Zr．Amongthethreetreatmentstates，homogenizingstate，hot-rollingstateandnormalizingstate，thehomogenizingstateh

7、adahighesthardness．Andthehot-rollinghadthelowesthardness，andthehardnessroseafternormalization．ThelatticeparametersincreasedalongwiththeincreaseofZrcontent．Thehomogenizinghadlargestlatticeparameters，whilethehot-rollingandnormalizationdecreasedtheparametersthroughdecreasingdefectinthealloysthenre

8、laxingthestructure．Theelasticresiliencereacheditsbestat3at％Zr．Generally，theelasticresiliencebecamebetterwiththeannealingtemperaturerisingexceptanabnormityat3at％Zr．ItwasrelatedtOtheMstemperatureofalloyswhichwasslightlylowerthanther