1
Materials department, Malek Ashtar university of Technology, Tehran, Iran
2
Malek Ashter University of Technology
3
malek ashtar university of technology
10.22034/frj.2023.357476.1163
Abstract
Abstract:
The new cobalt-nickel superalloys containing γ´ precipitates have been noticed due to their strength properties and higher corrosion resistance than nickel base superalloys. In the research, the effect of withdrawal rate in the directional solidification process on the structure and hardness of a new cobalt-nickel base superalloy has been investigated. For this purpose, Bridgman's directional solidification process was used for the directional growth of samples under vacuum at 1.5, 3, and 6 mm/min withdrawal rate. The results show that a directional structure was obtained at all speeds, and with the increase of the withdrawal rate, the distance between the primary dendritic arms increased from 176 to 147 μm, the distance between the secondary dendritic arms increased from 90 to 55 μm, and The size of γ´ precipitates decreases from 6.4 to 4.5 µm. These changes are due to the change in the heat transfer mechanism near the surface of the refrigerant and at a height above the surface of the refrigerant, as well as the increase in the supercooling temperature and the decrease in the freezing time with the increase in the extrusion speed, which changes the microstructure from rough dendritic to fine dendritic. The hardness results of the samples increased from 371 to 375 and (HV) 393 by increasing the withdrawal rate from 1.5 to 3 and 6 mm/min. The increase in hardness can be due to the regularization of the structure and the decrease in the size of γ´ precipitates.
Seifollahi, M., Ghazi mir Saeed, S. M., & abdolmaleki, F. (2023). Effect of withdrawal rate of directional solidification on the microstructure of a new Cobalt-Nickel based Superalloy. Founding Research Journal, (), -. doi: 10.22034/frj.2023.357476.1163
MLA
Masumeh Seifollahi; seyed Mahdi Ghazi mir Saeed; fatemeh abdolmaleki. "Effect of withdrawal rate of directional solidification on the microstructure of a new Cobalt-Nickel based Superalloy". Founding Research Journal, , , 2023, -. doi: 10.22034/frj.2023.357476.1163
HARVARD
Seifollahi, M., Ghazi mir Saeed, S. M., abdolmaleki, F. (2023). 'Effect of withdrawal rate of directional solidification on the microstructure of a new Cobalt-Nickel based Superalloy', Founding Research Journal, (), pp. -. doi: 10.22034/frj.2023.357476.1163
VANCOUVER
Seifollahi, M., Ghazi mir Saeed, S. M., abdolmaleki, F. Effect of withdrawal rate of directional solidification on the microstructure of a new Cobalt-Nickel based Superalloy. Founding Research Journal, 2023; (): -. doi: 10.22034/frj.2023.357476.1163
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