The coarsening behavior ofγʹprecipitate phase at different temperatures and the compressive performance of novel Co-Ni-Al-W superalloy were investigated.Experiment results show that the evolution of the mean radius a...The coarsening behavior ofγʹprecipitate phase at different temperatures and the compressive performance of novel Co-Ni-Al-W superalloy were investigated.Experiment results show that the evolution of the mean radius and volume fraction of theγʹphase obeys the classical Lifshitz-Slyozov-Wagner model.The coarsening rate of theγʹphase exhibits a significant dependence on the aging temperature,which increases from 1.30×10^(−27)m^(3)/s at 800℃to 9.56×10−27 m^(3)/s at 900℃.The activation energy ofγʹphase is mainly influenced by the W diffusion in theγmatrix,presenting as 210 kJ/mol.The prepared Co-Ni-Al-W alloy possesses superb comprehensive properties,particularly the good combination of highγʹsolvus temperature(1221℃)and low density(8.7 g/cm^(3)).Besides,the compressive yield strength of the Co-Ni-Al-W alloy at ambient and high temperatures are higher than that of otherγʹ-strengthened Co-based superalloys.The compressive yield strength of the Co-Ni-Al-W alloy at 850℃is as high as 774 MPa.展开更多
In this research, the Co-9Al-7. 5 W superalloy was deposited on the 304 austenite stainless steel plate by tungsten inert gas （T1G） cladding technique. The cladding layer shape, dilution, microharclness, microstruct...In this research, the Co-9Al-7. 5 W superalloy was deposited on the 304 austenite stainless steel plate by tungsten inert gas （T1G） cladding technique. The cladding layer shape, dilution, microharclness, microstructure and distribution of alloying elements were investigated. The cladding layer is characterized by large dilution rate, fine microstructure, narrow heat-affected zone, narrow alloying elements segregation, high hardness, high contents of alloying elements and low contents of Fe.展开更多
TIG welding was used to deposit Co-8.8 Al-9.8 W-0.2 B superalloy on 304 austenite stainless steel. The form factor of weld, dilution ratio, microhardness, microstructure and distribution of alloying elements were inve...TIG welding was used to deposit Co-8.8 Al-9.8 W-0.2 B superalloy on 304 austenite stainless steel. The form factor of weld, dilution ratio, microhardness, microstructure and distribution of alloying elements were investigated. The microstructure of cladding layer was mainly hypoeutectic. The primary phases were cobalt-rich solid solution. The eutectic phase was composed of cobalt-rich solid solution,Co6W6C and Co Cx. When the boron content increased from 0.2% to 0.5%,the dilution ratio decreased,the primary phase became coarse and the microhardness decreased. When the boron content was from 0.5% to 2%,the dilution ratio and microhardness increased obviously,but the primary phase was refined.The hard phase of Co-8.8 Al-9.8 W became refined and the amount was raised,and the performance of cladding layer was improved with appropriate boron increase.展开更多
基金Natural Science Foundation of Liaoning Province(2023-MSLH-337)。
文摘The coarsening behavior ofγʹprecipitate phase at different temperatures and the compressive performance of novel Co-Ni-Al-W superalloy were investigated.Experiment results show that the evolution of the mean radius and volume fraction of theγʹphase obeys the classical Lifshitz-Slyozov-Wagner model.The coarsening rate of theγʹphase exhibits a significant dependence on the aging temperature,which increases from 1.30×10^(−27)m^(3)/s at 800℃to 9.56×10−27 m^(3)/s at 900℃.The activation energy ofγʹphase is mainly influenced by the W diffusion in theγmatrix,presenting as 210 kJ/mol.The prepared Co-Ni-Al-W alloy possesses superb comprehensive properties,particularly the good combination of highγʹsolvus temperature(1221℃)and low density(8.7 g/cm^(3)).Besides,the compressive yield strength of the Co-Ni-Al-W alloy at ambient and high temperatures are higher than that of otherγʹ-strengthened Co-based superalloys.The compressive yield strength of the Co-Ni-Al-W alloy at 850℃is as high as 774 MPa.
基金Acknowledgements This study was financially supported by West Light Foundation of the Chinese Academy of Science （Grant No. 0901ZBB066） , the Natural Science Foundation of Gansu Province （Grant No. 099 RJYA018 ）.
文摘In this research, the Co-9Al-7. 5 W superalloy was deposited on the 304 austenite stainless steel plate by tungsten inert gas （T1G） cladding technique. The cladding layer shape, dilution, microharclness, microstructure and distribution of alloying elements were investigated. The cladding layer is characterized by large dilution rate, fine microstructure, narrow heat-affected zone, narrow alloying elements segregation, high hardness, high contents of alloying elements and low contents of Fe.
基金supported by the National Natural Science Foundation of China(Grant No.51561019)
文摘TIG welding was used to deposit Co-8.8 Al-9.8 W-0.2 B superalloy on 304 austenite stainless steel. The form factor of weld, dilution ratio, microhardness, microstructure and distribution of alloying elements were investigated. The microstructure of cladding layer was mainly hypoeutectic. The primary phases were cobalt-rich solid solution. The eutectic phase was composed of cobalt-rich solid solution,Co6W6C and Co Cx. When the boron content increased from 0.2% to 0.5%,the dilution ratio decreased,the primary phase became coarse and the microhardness decreased. When the boron content was from 0.5% to 2%,the dilution ratio and microhardness increased obviously,but the primary phase was refined.The hard phase of Co-8.8 Al-9.8 W became refined and the amount was raised,and the performance of cladding layer was improved with appropriate boron increase.
