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Effects of alloying elements on microstructure and mechanical properties of Co���Ni���Al���Ti superalloy

Journal Article


Abstract


  • The effects of the relative content of Al and Ti, and the addition of 2 at.% Cr or Mo to partly substitute Co on the microstructure and mechanical properties of Co���Ni���Al���Ti superalloy were investigated. The microstructures of five as-cast superalloys showed that ��'-(Co,Ni)3(Al,Ti) precipitates segregated on ��-Co matrix and exhibited dendritic morphology. After aging, nano-sized ��'-(Co,Ni)3(Al,Ti) precipitates uniformly precipitated on ��-Co matrix. Ni, Al, Ti and Mo atoms partitioned preferentially to ����� phase, while Co and Cr atoms partitioned preferentially to �� matrix phase. The increase in Ti content, and the addition of 2 at.% Cr or Mo all increased the volume fraction and the average size of ����� phase. The lattice misfit increased with the concentration of Ti and the addition of 2 at.% Mo, but decreased with the addition of 2 at.% Cr. With increasing aging time, the size of ����� phase and lattice misfit increased, while ����� phase volume fraction increased firstly, and then decreased after reaching the maximum at 100 h. The lattice misfit plays a key role on vicker's hardness in the time of 20 h���100 h aging, while ����� phase volume fraction plays a decisive role in vicker's hardness after 100 h aging.

Publication Date


  • 2020

Citation


  • Gao, Q., Jiang, Y., Liu, Z., Zhang, H., Jiang, C., Zhang, X., & Li, H. (2020). Effects of alloying elements on microstructure and mechanical properties of Co���Ni���Al���Ti superalloy. Materials Science and Engineering A, 779. doi:10.1016/j.msea.2020.139139

Scopus Eid


  • 2-s2.0-85080054418

Volume


  • 779

Issue


Place Of Publication


Abstract


  • The effects of the relative content of Al and Ti, and the addition of 2 at.% Cr or Mo to partly substitute Co on the microstructure and mechanical properties of Co���Ni���Al���Ti superalloy were investigated. The microstructures of five as-cast superalloys showed that ��'-(Co,Ni)3(Al,Ti) precipitates segregated on ��-Co matrix and exhibited dendritic morphology. After aging, nano-sized ��'-(Co,Ni)3(Al,Ti) precipitates uniformly precipitated on ��-Co matrix. Ni, Al, Ti and Mo atoms partitioned preferentially to ����� phase, while Co and Cr atoms partitioned preferentially to �� matrix phase. The increase in Ti content, and the addition of 2 at.% Cr or Mo all increased the volume fraction and the average size of ����� phase. The lattice misfit increased with the concentration of Ti and the addition of 2 at.% Mo, but decreased with the addition of 2 at.% Cr. With increasing aging time, the size of ����� phase and lattice misfit increased, while ����� phase volume fraction increased firstly, and then decreased after reaching the maximum at 100 h. The lattice misfit plays a key role on vicker's hardness in the time of 20 h���100 h aging, while ����� phase volume fraction plays a decisive role in vicker's hardness after 100 h aging.

Publication Date


  • 2020

Citation


  • Gao, Q., Jiang, Y., Liu, Z., Zhang, H., Jiang, C., Zhang, X., & Li, H. (2020). Effects of alloying elements on microstructure and mechanical properties of Co���Ni���Al���Ti superalloy. Materials Science and Engineering A, 779. doi:10.1016/j.msea.2020.139139

Scopus Eid


  • 2-s2.0-85080054418

Volume


  • 779

Issue


Place Of Publication