Application of DSC Method in Studies on Phase Transitions of Ni Superalloys

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Abstract

The paper presents results of calorimetric studies of foundry nickel superalloys: IN100, IN713C, Mar-M247 and ŻS6U. Particular attention was paid to determination of phase transitions temperatures during heating and cooling. The samples were heated to a temperature of 1500°C with a rate of 10°C⋅min-1 and then held at this temperature for 5 min. After a complete melting, the samples were cooled with the same rate. Argon with a purity of 99.99% constituted the protective atmosphere. The sample was placed in an alundum crucible with a capacity of 0.45 cm3. Temperature and heat calibration was carried out based on the melting point of high-purity Ni. The tests were carried out by the differential scanning calorimetry (DSC) using a Multi HTC high-temperature calorimeter from Setaram. Based on the DSC curves, the following temperatures were determined: solidus and liquidus, dissolution and precipitation of the γ’ phase, MC carbides and melting of the γ’/γ eutectic. In the temperature range of 100-1100°C, specific heat capacity of the investigated superalloys was determined. It was found that the IN713C and IN100 alloys exhibit a higher specific heat while compared to the Mar-M247 and ŻS6U alloys.

[1] Sims, S.T., Stoloff, N.S., Hagel, W.C. (1987). Superalloys II. New York: Ed. John Wiley & Sons.

[2] Mikułowski, B. (1997). High temperature cast alloys and Nikel-based superalloys. Cracow: Publication AGH.

[3] Zrnik, J., Strunz, P., Vrchovinsky, V., Muransky, O., Novy, Z. & Widenmann, A. (2004). Degradation of creep properties in a long-term thermally exposed nickel base superalloy. Materials Science and Engineering. A 387-389, 728-733.

[4] Lee, S.H., Kim, S.W. & Kang, K.H. (2006). Effect of heat treatment on the specific heat capacity of nickel-based alloys. Journal of Thermophysic. 27(1), 282-292.

[5] Liu, L.R., Jin, T., Zhao, N.R., Zhang, Z.H., Shun, X.F., Guan, H.R. & Hu, Z. Q. (2003). Microstructural evolution of a single crystal nickel-base superalloy during thermal exposure. Material Letters. 57, 4540-4546.

[6] Balikci, E. & Raman, A., (2004). Characteristics of the γ’ precipitates at high temperatures in Ni-base polycrystalline superalloy IN738 LC. Journal of Materials Chemistry. and Physics. 84, 284-290.

[7] Suwardiea, J.H., Artiagab, R. & Mierb, J.L. (2002). Thermal characterization of a Ni-based superalloy. Thermochemica Acta. 392-393, 295-298.

[8] D’Souzaa, N. & Dongb, H.B. (2007). Solidification path in third-generation Ni-based superalloys, with an emphasis on last stage solidification. Scripta Materialia. 56, 41-44.

[9] Bhambri, A.K., Kattamis, T.Z. & Morral, J.E. (1975). Cast microstructure Inconel 713C and its dependence on solidification variables. Metallurgical Tranactions. B 6B, 523-537.

[10] Zupanic, F., Boncina, T., Krizman, A. & Tichelaar, F.D. (2001). Structure of continuously cast Ni-based superalloy Inconel 713C. Journal of Alloys and Compounds. 329, 290-297.

[11] Przeliorz, R. & Piątkowski, J. (2015) Thermophysical Properties of Nickel-Based Cast Superalloys. Metalurgija. 54(3), 543-546.

Archives of Foundry Engineering

The Journal of Polish Academy of Sciences

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CiteScore 2016: 0.42

SCImago Journal Rank (SJR) 2016: 0.192
Source Normalized Impact per Paper (SNIP) 2016: 0.316

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