Si元素对Ti6246合金显微组织和力学性能的影响  

Effect of Si Element on Microstructure and Mechanical Properties of Ti6246 Alloy

作　　者：周涛 朱绍祥[2] 王清江[2] Zhou Tao;Zhu Shaoxiang;Wang Qingjiang(Air China Shenyang Engine Research Institute,Shenyang 110043,China;Shi Changxu Innovation Center for Advanced Materials,Institute of Metal Research,Chinese Academy of Sciences,Shenyang 110016,China)

机构地区：[1]中国航发沈阳发动机研究所,辽宁沈阳110043 [2]中国科学院金属研究所师昌绪先进材料创新中心,辽宁沈阳110016

出　　处：《钛工业进展》2024年第5期1-8,共8页Titanium Industry Progress

摘　　要：为了提高航空发动机整体叶盘用Ti6246合金的力学性能,利用扫描电子显微镜(SEM)、透射电子显微镜(TEM)等检测和分析技术,研究了Si元素对Ti6246合金力学性能及硅化物析出的影响,并结合JMatpro软件分析了硅化物的成分、结构及析出机制。结果表明,Si元素含量从0%增加到0.1%(质量分数,下同)时,Ti6246合金455℃的残余蠕变下降较为明显;Si元素含量为0.2%时,Ti6246合金中有硅化物析出,室温塑性出现波动,残余蠕变与0.1%合金相比变化不大;Si元素含量为3.0%时,Ti6246合金拉伸强度高、塑性较差,与Si元素含量不大于0.2%的合金相比,残余蠕变略有上升,组织中出现粗大的(Ti,Zr)_(6)Si_(3)(S_(2)型)硅化物。含3.0%Si元素的Ti6246合金中,硅化物在凝固过程中由液相析出,αp相与β相中无析出。TEM分析结果显示,硅化物与基体具有非共格的取向关系:(2201)S_(2)~(1011)α;(1120)S_(2)∥(1456)α。Zr、Si原子间更大的结合力促进了硅化物的析出,但由于液相中大量析出(Ti,Zr)6Si3硅化物,造成固相基体中Zr元素严重匮乏,因此在后续的时效过程中无二次硅化物析出。粗大的S_(2)型硅化物对晶界和α/β相界的强化效果不明显,故含3.0%Si元素的Ti6246合金蠕变性能未得到提高。In order to improve the mechanical properties of the Ti6246 alloy used in aero-engine blade integrated disk,the influence of Si element on the mechanical properties and silicides precipitation of Ti6246 alloy was studied by SEM and TEM.The composition,structure,and precipitation mechanism of silicides were analyzed by JMatpro software.The results show that the residual creep at 455℃decreases noticeably as the content of Si element increases from 0%to 0.1%(mass fraction,the same below)in Ti6246 alloy.When the content of Si element is 0.2%,there are silicides precipitated in Ti6246 alloy,the plasticity fluctuated at room temperature and the residual creep is little changed compared with the 0.1%alloy.When the content of Si element is 3.0%,the tensile strength of Ti6246 alloy is high,but its plasticity is poor.The residual creep is slightly increases which compared with the alloy containing less than 0.2%Si element,the coarse(Ti,Zr)6Si3(S_(2)type)silicide appears in the structure.The silicides are precipitated from the liquid phase during the solidification process,rather than from theαp phase andβphase in the Ti6246 alloy containing 3.0%Si element.TEM analysis indicates an incoherent orientation relation between silicides and matrix:(2201)S_(2)~(1011)α;(1120)S_(2)∥(1456)α.The greater bonding between Zr and Si atoms promote the precipitation of silicides.Due to the large amount of(Ti,Zr)6Si_(3)silicide precipitated in the liquid phase,the Zr element in the solid phase matrix is seriously deficient,so no secondary silicides precipitated in the subsequent aging process.The coarse S_(2)type silicide has no obvious strengthening effect on grain boundary andα/βphase boundary.Therefore,the creep property of the Ti6246 alloy containing 3.0%Si element is not improved.

关 键 词：高温钛合金 结构分析 Ti6246合金 硅化物 力学性能 

分 类 号：TG146.23[一般工业技术—材料科学与工程]