【摘要】 采用真空热压烧结制备了Nb-22.5Cr-xSi（x=0、5、10、15）合金，通过XRD、SEM、显微硬度、断裂韧度、室温压缩实验研究了Si含量对合金组织及性能的影响。结果表明：随着Si含量的增加，合金由Nb固溶体和Laves相NbCr₂两相组成逐步转变为Nb固溶体、Laves相NbCr₂、Nb₅Si₃和少量Nb₃Si四相组成。随着Si含量的增加，合金的硬度先降后升；与此同时，合金的断裂韧性和室温压缩强度先升后降。Nb-22.5Cr-5Si合金的硬度，压缩强度，塑性应变分别是6.46 GPa,3 144 MPa和13.2%，同时具有良好的断裂韧性。更多还原

【Abstract】 The Nb-22.5Cr-xSi alloys （x=0,5,10,15） were prepared by vacuum hot pressing sintering.The effect of Si on microstructure and properties of Nb-22.5Cr-xSi alloy were studied by XRD,SEM,microhardness,fracture toughness and room-temperature compression test.The results show that the phase composition of Nb-22.5Cr-xSi alloy changes from Nb solid solution（Nbss） and Laves phase NbCr₂ to Nbss,Laves phase NbCr₂,Nb₅Si₃ and some Nb₃Si with the increase of Si content.The microhardness of of Nb-22.5Cr-xSi alloys decreases firstly and then increases with the increase of Si content.Meanwhile,the fracture toughness and room-temperature compression strength increase firstly and then decrease.The microhardness,room-temperature compression strength and plastic strain of Nb-22.5Cr-5Si alloy with good fracture toughness are 6.46 GPa,3 144 MPa and 13.2%,respectively.更多还原