合金元素对含锯钛铝合金组织与性能优化研究

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Abstract：Toimprove theroom-temperature strengthandductilityofTi45Al4Nb1Cralloy，Mo wasaddedasanallying elementintherange ofO-O.9 at%.Systematic investigations were subsequentlyconducted onthe microstructure and mechanical propertiesof the Ti45Al4Nb1Cr- x Moalloys.The results show that the averagewidth of grains of alloys decreases withthe increaseofMocontent.MoadditionpromotestheformationofB2phaseboth inthedendritesandininterdendritic regions，anditscontentincreaseswithincreasingMocontent.ThealloywithO.6at%Moexhibitshighercomprehensivemechanical properties with the ultimate compressive strength and fracture strain of 1882.3 MPa and 32.4% ，respectively. The improvements inboth strengthandstrainareprimarilyatributed tothegrainrefinementstrengtheningand solid-solution strengtheningbyMoaddition.However，exessiveModditionresultsinthedecreaseinthestrengthandstrain，whichisattributed to the excessive B2 phase that acts as the cracking sources during compression.

Keywords： TiAl; Mo; B2 phase; microstructure;mechanical properties

高Nb含量TiAl合金（以下简称TiAl-Nb合金） 的高温蠕变性能，被认为是下一代涡轮发动机和现因其具有低密度、高比强度、高弹性模量以及优异 代地面能源转换系统中高温应用领域极具潜力的

候选材料，因而在过去二十年中被广泛研究。（剩余6414字）