资源描述：
《热处理对tc21钛合金组织和性能的影响》由会员上传分享，免费在线阅读，更多相关内容在学术论文-天天文库。
1、一，一—.一面~.一ABSTRACT，一ABSTRACTThispaperdetailstheinfluenceofthermomechanicalprocessing(TMP)onthemicrostructuresandmechanicalpropertiesofTC21titaniumalloy,anewalpha+betaalloywithhighstrength,ductilityandtoughnessdevelopedinChina.ByusingEDS,SEM,TEMandopticalm
2、icroscope,theeffectofmi-crostructureonmechanicalpropertiesundervariousconditionsofdeformationandheattreatmenthasbeeninvestigatedandthestrengtheningandtougheningmechanismhasbeenresearched.Moreover,thethermalstabilityofthealloyhasbeenstudied.Manyvaluableres
3、ultshavebeenobtainedinthestudy.Alpha+betahotworking,a1p-solutiontreatmentplusagingdevelopsanequiaxedmicrostruc-ture,whichhasmoderatestrength,enoughductileandlowfracturetoughnessandgoeswithdimpledfailure.Whereasbetahotworking,a1p-solutiontreat-mentplusagin
4、gdevelopsalamellartransformed-betamicrostructure,whichhashighstrength,lowductileandhighfracturetoughnessandgoeswithtransgranularbrittlenessfailure.Withtheascentofthesolutiontreattem-peratureorthedecreaseofcoolingratefromthesolutiontreattemperature,theamou
5、ntofthetransformed-betaphaseincreasesandsodoesthetensilestrengthofthealloybuttheductilitydecreases.Withincreaseofagingtem-peratureoragingtime,thetensilestrengthincreasesfirstlyandthendecreasesForoptimumstrength,ductilityandtoughness,TMProuteisthatbetaproc
6、essfollowedalp-solutiontreatmentplusaging.Themicrostructureofthealloyhasnomuchdifferenceafterlongtermaging,whiletheprecipitateofa2-Ti3A1hasbeenidentifiedinelectrondiffractionpatterns.Afewinterfacephasehasbeenobservedinthisalloy.Keywords:titaniumalloy;ther
7、momechanicalprocessing;microstructure;fracturetoughness;precipitates;interfacephase一n一第1章绪论第1章绪论1.1研究背景钦及钦合金具有许多优点，如比强度高、导热系数低、耐腐蚀、良好的中低温性能，由于这些优点，从50年代开始，在较短的时间内，钦工业得到了迅速的发展，钦及钦合金已广泛应用于航空、航天、化工、石油、冶金、电力、舰船及医疗器械等行业，被誉为“现代金属”、“第三金属”、“战略金属=[1-4]。即便如此目前钦合金开发
8、和应用的重点仍然是航空航天工业的结构件。作为结构件，传统的选材判据只包括三个基本因素:未损伤材料的静强度及刚度;未损伤材料的疲劳性能;高温使用时的蠕变、持久和热稳定性。二十世纪五十年代英国“彗星”式客机的失事，使得传统的设计概念受到了怀疑.随着人们认识的加深和断裂力学的发展，航空器结构废弃了单纯的静强度设计概念，采用了结构完整性和损伤容限概念，增加了两个新因素:己损伤材料的静强度和己损伤材料的疲劳性能。综合在一起，称为现代航空
