Contrastive Studies between Laser Repairing and Plasma Arc Repairing on Single-Crystal Ni-Based Superalloy

• Published in: Materials Vol. 12; no. 7; p. 1172
• Main Authors: Wang, Cheng, Li, Qiuliang, Zhou, Xin, Zhu, Wenxin, Huang, Runqiu, Pan, Zhihao, Chen, Kai, He, Chang
• Format: Journal Article
• Language: English
• Published: Switzerland MDPI AG 10.04.2019; MDPI
• Subjects: Additive manufacturing; Crack propagation; Cracks; Crystal growth; Electric arc melting; Epitaxial growth; Grain boundaries; laser repairing; Lasers; Letter; Mechanical properties; Microhardness; Microstructure; Modulus of elasticity; Ni-based superalloy; Nickel base alloys; Plasma; plasma arc repairing; Plasma jets; Precipitates; Scanning electron microscopy; single crystal; Single crystals; Solidification; Superalloys; Turbines; plasma arc repairing; Ni-based superalloy; single crystal; laser repairing
• ISSN: 1996-1944; 1996-1944
• DOI: 10.3390/ma12071172

Laser repairing and plasma arc repairing experiments on the single-crystal Ni-based superalloy DD407(Ni-7.82Cr-5.34Co-2.25Mo-4.88W-6.02Al-1.94Ti-3.49Ta in wt.%) were carried out in this paper, and the differences in microstructures and mechanical properties varying with depth between the two repairing methods were studied. Comparing the two repairing processes, both the fusion zone can maintain single-crystal epitaxial growth with no significant cracks and have similar fine γ' precipitates. Nevertheless, the columnar-to-equiaxed transition phenomenon occurred on the top of the fusion zone during the laser re-melting process but was not very obvious on the top surface of the fusion zone during the plasma arc re-melting process. In addition, both the DD407 superalloy conducted with the two repairing processes had a large microhardness and a great Young's modulus in the fusion zone.