Ti-43Al-6Nb-1Mo-1Cr- ( C/Y2O3）合金850℃拉伸性能及蠕变行为的研究
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Abstract： The superior high temperature performance and creep resistance of high Nb-TiAl alloy make it very promising asaeroengine structural materials.Inthis paper，a water-cooled copper crucible vacuum induction melting furnace （ISM） was used to prepare Ti-43Al-6Nb-1Mo-1Cr-0.1C（T43-0.1C），Ti-43Al-6Nb-1Mo-1Cr- ⋅0.05Y2O3 （T43.0.05Y2O3 ）two alloys，the high temperature tensile properties and creep resistance of two high Nb-TiAl alloys have been studied.The tensile properties and creep properties of the two alloys at a high temperature of 850°C were tested.The deformation zone structure and fracture morphology of the two aloys were observed by scanning electron microscopy and transmisson electron microscopy. The fracture mechanism was studied and the C and Y2O3 in high Nb-TiAl were analyzed.The strengthening mechanism of the alloy.The results show thatthe maximum strain of T43-0.1C is 4.380% ，the maximum tensile strength is 578MPa ， the maximum strain of T43-0.05Y2O3 alloy is 12.30% ，and the maximum tensile strength is 620MPa under 850°C tension. The alloy fractures in a combination of brittleness and toughness at a high temperature of 850∘C . The strengthening of the T43-0.1C alloy mainly comes fromthe solid solution strengthening of C，but 0.1C reduces the room temperature plasticity. The strengthening of the T43-0.05Y2O3 alloymainly comes from the fine grain strengthening of the Y2O3 particlesand the second phase strengthening. The creep performance of T43-O.1C alloyisbetter than T43-0.05Y2O3 alloy at 850∘ C.The fracture mechanismofT43-O.1Callyistheinitiationandpropagationofcracksatthegrainboundary，which eventually causes the separation of the grain boundary. The fracture mechanism of T43-0.05 Y2O3 alloy is void nucleation， growth， and interconnection.
Keywords： high Nb-TiAl alloy; high temperature tensile; high temperature creep; creep mechanism
1序言
减轻结构质量可以减少碳排放、提高飞机性能，质量更轻和强度更大的材料可使飞机具有更大的飞行航程和飞行速度，也有助于降低成本。（剩余8555字）
