A Study on the Microstructural Characterization of René 142 Deposited Atop René 125 Processed through Scanning Laser Epitaxy

Abstract:

Advancements in the design, optimization and manufacture of turbine engine hot-section components during the past few decades have contributed enormously to the improvement in power-ratings and efficiency levels of gas turbine engines. Nickel-base superalloys are extensively used to produce the hot-section components as this class of alloys offer improved creep strength and higher fatigue resistance compared to other alloys due to the presence of precipitate-strengthening γ' phases i.e. Ni₃[Ti, Al, Ta etc.] in the normally face centered cubic (FCC) structure of the solidified nickel. Although this second phase is the main reason for the improvement in properties, it also results in increased processing difficulty as these alloys are prone to crack formation. In this work, we demonstrate powder-bed additive manufacturing of René 142 onto René 125 substrates through scanning laser epitaxy (SLE). René 142 is a high strength, nickel-base directionally solidified (DS) alloy that has high rupture strength, excellent resistance to grain boundary cracking, and superior high-velocity oxidation resistance. Successful deposition of René 142 on René 125 provides an avenue to repair legacy hot-section components by depositing superior quality alloys at the damage locations. The microstructure of the deposited René 142 is observed to follow the polycrystalline or EQ morphology of the underlying René 125 substrate. The SLE processed René 142 exhibits dense and crack-free deposits, and microstructure refinement compared to the underlying cast René 125 substrate. This work is sponsored by the Office of Naval Research through grants N00014-11-1-0670 and N00014-14-1-0658.

• Periodical: Materials Science Forum (Volume 879)
• Pages: 187-192
• DOI: https://doi.org/10.4028/www.scientific.net/MSF.879.187
• Online since: November 2016
• Authors: Amrita Basak*, Suman Das
• Keywords: Additive Manufacturing, Nickel-Base, René 125, René 142, Scanning Laser Epitaxy (SLE), Single-Crystal, Superalloy

References

[1] Ross EW, O'hara KS. Rene'142- A high strength, oxidation resistant DS turbine. Superalloys 1992. 1992: 257-65.

DOI: 10.7449/1992/superalloys_1992_257_265

[2] Acharya R, Bansal R, Gambone JJ, Das S. A Coupled Thermal, Fluid Flow, and Solidification Model for the Processing of Single-Crystal Alloy CMSX-4 Through Scanning Laser Epitaxy for Turbine Engine Hot-Section Component Repair (Part I). Metallurgical and Materials Transactions B. 2014; 45: 2247-61.

DOI: 10.1007/s11663-014-0117-9

[3] Acharya R, Bansal R, Gambone JJ, Das S. A Microstructure Evolution Model for the Processing of Single-Crystal Alloy CMSX-4 Through Scanning Laser Epitaxy for Turbine Engine Hot-Section Component Repair (Part II). Metallurgical and Materials Transactions B. 2014; 45: 2279-90.

DOI: 10.1007/s11663-014-0183-z

[4] Acharya R, Bansal R, Gambone JJ, Kaplan MA, Fuchs GE, Das S, et al. Additive Manufacturing and Characterization of René 80 Superalloy Processed Through Scanning Laser Epitaxy for Turbine Engine Hot‐Section Component Repair. Advanced Engineering Materials. (2015).

DOI: 10.1002/adem.201400589

[5] Acharya R, Das S. Additive Manufacturing of IN100 Superalloy Through Scanning Laser Epitaxy for Turbine Engine Hot-Section Component Repair: Process Development, Modeling, Microstructural Characterization, and Process Control. Metallurgical and Materials Transactions A. 2015: 1-12.

DOI: 10.1007/s11661-015-2912-6

[6] Basak A, Acharya R, Bansal R, Das S. Scanning Laser Epitaxy – A Novel Metal Additive Manufacturing Process Developed for Gas Turbine Hot-Section Alloys. Materials Science and Technology. Columbus, Ohio. (2015).

[7] Gambone JJ. Quantitative metallography tracking and analysis for the scanning laser epitaxy process applied to CMSX-4 and Rene-80 nickel-based superalloys. (2012).