摘要
Three Laves phase-based alloys with nominal compositions of Cr2Nb-xTi （x = 20, 30, 40, in at%） have been prepared through vacuum non-consumable arc melting. The results show that the microstructures of Cr2Nb-（20, 30） Ti alloys are composed of the primary Laves phase C15-Cr2（Nb,Ti） and bcc solid solution phase, while the microstructure of Cr2Nb-40Ti alloy is developed with the eutectic phases C15-Cr2（Nb,Ti）/bcc solid solution. The measured fracture toughness of ternary Laves phase C15-Cr2（Nb,Ti） is about 3.0 MPa m1/2, much larger than 1.4 MPa m1/2 for binary Laves phase Cr2Nb. Meanwhile, the fracture toughness of Cr2Nb-xTi （x = 20, 30, 40） alloys increases with increasing Ti content and reaches 10.6 MPa m1/2 in Cr2Nb-40Ti alloy. The eutectic microstructure and addition of Ti in Cr2Nb are found to be effective in toughening Laves phase-based alloys.
Three Laves phase-based alloys with nominal compositions of Cr2Nb-xTi （x = 20, 30, 40, in at%） have been prepared through vacuum non-consumable arc melting. The results show that the microstructures of Cr2Nb-（20, 30） Ti alloys are composed of the primary Laves phase C15-Cr2（Nb,Ti） and bcc solid solution phase, while the microstructure of Cr2Nb-40Ti alloy is developed with the eutectic phases C15-Cr2（Nb,Ti）/bcc solid solution. The measured fracture toughness of ternary Laves phase C15-Cr2（Nb,Ti） is about 3.0 MPa m1/2, much larger than 1.4 MPa m1/2 for binary Laves phase Cr2Nb. Meanwhile, the fracture toughness of Cr2Nb-xTi （x = 20, 30, 40） alloys increases with increasing Ti content and reaches 10.6 MPa m1/2 in Cr2Nb-40Ti alloy. The eutectic microstructure and addition of Ti in Cr2Nb are found to be effective in toughening Laves phase-based alloys.
基金
financially supported by the National Natural Science Foundation of China (Nos.51074127 and 51104120)
the SRF for ROCS,SEM
