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时间:2020-04-30
《SiC含量对机械合金化-热压制备B4C-SiC复合陶瓷的影响.pdf》由会员上传分享,免费在线阅读,更多相关内容在行业资料-天天文库。
1、第29卷第7期无机材料学报Vl0I_29NO.72014年7月JournalofInorganicMaterialsJu1..2014文章编号:1000-324X(2014)07-0695-06D0I:10.3724/SP.J.1077.2014.13521SiC含量对机械合金化一热压制备B4C.SiC复合陶瓷的影响张志晓,杜贤武,邢伟宏2,王为民,张金咏,傅正义(武汉理工大学1.材料复合新技术国家重点实验室;2.材料科学与工程学院武汉430070)摘要:以B4C、SiC粗粉为原料,采用机械合金化辅助热压烧结工艺
2、,在不添加任何助烧剂的情况下于195O℃制备出致密的BC.SiC复合陶瓷。通过对烧结样品进行相对密度、维氏硬度、抗弯强度和断裂韧性测试,研究SiC含量对复合陶瓷力学性能的影响;结合XRD、SEM和TEM对样品进行组分和微观结构分析,研究其微观结构与力学性能之间的关系。结果表明:复合陶瓷的相对密度和断裂韧性随SiC含量的增加而增大,当SiC含量为50wt%时获得最大值为96.1%和4.6MPa.m“;复合陶瓷的硬度和抗弯强度随SiC含量的增加呈先增大后减小的趋势,在SiC含量为20wt%时获得最大值25.5GPa和
3、480MPa。SiC相均匀分布在B4C基体中使得复合陶瓷具有较高的强度;B4C与SiC之间好的界面相容性以及SiC的高断裂韧性是该B4C基复合陶瓷韧性得到显著提高的原因。关键词:复合陶瓷;热压;机械合金化;力学性能;微观结构中图分类号:TQ174文献标识码:AEffectofSiCContentonB4C·SiCCompositesFabricatedbyMechanicalAlloying—hotPressingZHANGZhi.Xiao,DUXian.Wu,XINGWei.Hong,WANGWei—Min,Z
4、HANGJin.Yong,FUZheng.Yi(1.KeyLaboratoryofAdvancedTechnologyforMaterialsSynthesisandProcessing,2.schoolofMaterialsscienceandEngi-neering,WuhanUniversityofTechnology,Wuhan430070,China)Abstract:DenseB4C-SiCcompositeceramicswerefabricatedthroughmechanicalalloying
5、usingcoarserB4CandSiCpowdersasstartingpowders,andsubsequenthotpressingsinteringat1950~withoutanysinteringaid.Thein—fluencesofthecontentofSiConmechanicalpropertiesofthecompositeceramicswerestudiedthroughdeterminingrelativedensityofcompositeceramics,Vickershard
6、ness,flexurestrengthandfracturetoughness.CombinedwiththemicrostructureandcomponentanalysistechnologiesofXRD,SEMandTEM,therelationshipbetweenmicrostructureandmechanicalpropertiesofthecompositeceramicswasinvestigated.Theresultsindicatethattherelativedensityandf
7、racturetoughnessofthecompositeceramicsareimprovedwithincreaseofSiCcontent,andreachthemaximumvalueat96.1%and4.6MPa.m。respectively,withSiCcontentof50wt%.However,withtheincreaseofSiC,theVickershardnessandflexurestrengthareenhancedfirstlyandthendecreased.Themaxim
8、umvaluesare25.5GPaand480MPa,respectively,withSiCcontentof20wt%.HomogeneousdispersionofSiCphaseinB4Cmatrixisoneofthereasonswhythecompositeceramicspossesshigherflexurestrength.Fracturetough
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