عنوان مقاله [English]
نویسندگان [English]چکیده [English]
In this research, TLP bonding was used for dissimilar joints of IN-738/FSX-414 system using MBF-80 interlayer with the thickness of 50µm. TLP bonding was carried out at optimum condition (1150oC/5min) in a vaccuum furnace. Then, in order to refine the microstructure and increase the mechanical properties of the joints, homogenization treatment was carried out at 1175, 1200 and 1225oC for 1, 3 and 6 h. Optical microscope and scanning electron microscope (SEM) were used for microstructural studies and phase analysis was done using SEM/WDS analysis. Microstructural studies showed that homogenization at 1175oC/6h had no effect on removing the diffusion affected zone (DAZ) phases, but considerable reduction of these phases has occurred at 1200oC/1h. Homogenization at 1225oC for 1h caused formation of grain boundaries and secondary eutectic phases at the joint as well as coarsening of precipitates at the joint and base metal. Profile of alloying elements concentration across the joint showed that precipitation and coarsening of at the base metal and diffusion of alloying elements were the controlling factors of homogenization. Considerable reduction in the slope of alloying elements concentration profile at 1200oC was due to the rapid diffusion through the grain boundaries of the joint. Therefore, the optimum microstructural features were seen at 1225oC/1h homogenization condition.
1- Bakhtiari, R., Ekrami, A. (2012). Transient liquid phase bonding of FSX-414 superalloy at the standard heat treatment condition. Materials Characterization A, 66, 38-45.
2- Bakhtiari, R., Ekrami, A. (2012). The effect of gap size on the microstructure and mechanical properties of the transient liquid phase bonded FSX-414 superalloy. Materials and Design, 4, 130-137.
3- Bakhtiari, R., Ekrami, A., Khan, T.I. (2012). The effect of TLP bonding temperature on microstructural and mechanical property of joints made using FSX-414 superalloy. Materials Science and Engineering: A, 456, 291-300.
4- Ghoneim, A., Ojo, O. A. (2011). Microstructure and mechanical response of transient liquid phase joint in Haynes 282 superalloy. Material characterization, 62, 1–7.
5- Jalilvand, V., Omidvar, H., Shakeri, H. R., Rahimipour, M. R. (2013). Microstructural evolution during transient liquid phase bonding of Inconel 738LC using AMS 4777 filler alloy. Material characterization, 75, 20–28.
6- Jalilvand, V., Omidvar, H., Shakeri, H. R., Rahimipour, M. R. (2013). Inﬂuence of bonding variables on transient liquid phase bonding behavior of nickel based superalloy IN-738LC, Materials and Design, 52, 36–46.
7- Pouranvari, M., Ekrami, A., Kokabi, A. H. (2008). Microstructure–properties relationship of TLP-bonded GTD-111 nickel-base superalloy. Materials Science and Engineering:A, 490, 229–234.
8- Pouranvari,. M., Ekrami, A., Kokabi ,A. H. (2008). Microstructure development during transient liquid phase bonding of GTD-111 nickel-based superalloy. Journal of Alloys and Compounds, 461, 641–647.
9- Pouranvari, M., Ekrami, A., Kokabi, A. H. (2009). Effect of bonding temperature on microstructure development during TLP bonding of a nickel base superalloy. Journal of Alloys and Compounds, 469, 270–275.
10- Steven, R. A., Flewitt, P. E. J. (1978). Microstructural changes which occur during isochronal heat treatment of the nickel-base superalloy IN-738. Journal of Material Science, 13.2, 367-376.