Research on the Grain Boundary Liquation Mechanism in Heat Affected Zones of Laser Forming Repaired K465 Nickel-Based SuperalloyReport as inadecuate




Research on the Grain Boundary Liquation Mechanism in Heat Affected Zones of Laser Forming Repaired K465 Nickel-Based Superalloy - Download this document for free, or read online. Document in PDF available to download.

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State Key Laboratory of Solidification Processing, Northwestern Polytechnical University, Xi’an 710072, China

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Luoyang Ship Material Research Institute, Luoyang 471023, China





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Academic Editor: Johan Moverare

Abstract The damaged K465 nickel-based superalloy parts were repaired by laser forming repair technology. The cracking characteristics and grain boundary liquation in heat affected zones were investigated by optical microscopy OM, scanning electron microscopy SEM, and transmission electron microscopy TEM. It was found that the cracks originated from the heat-affected zone and extended to the repaired zone. The calculation by Thermol-Cale software showed that the larger γ′ particles at grain boundaries partly dissolved in the γ phase, which made the solutes’ concentration at the γ′-γ interface meet the eutectic-type liquation reaction condition of γ + γ′ → L. Then, grain boundaries liquation occurred and liquid films appeared with the temperature increasing in a rapid heating process. However, the intragranular γ′ phase completely dissolved into the γ phase with no devotion to the liquid film. The dissolution of M5B3 borides at grain boundaries could promote grain boundary liquation. View Full-Text

Keywords: laser forming repairing; K465 nickel-based superalloy; cracking; grain boundary liquation; γ′ phase laser forming repairing; K465 nickel-based superalloy; cracking; grain boundary liquation; γ′ phase





Author: Qiuge Li 1, Xin Lin 1,* , Xinghua Wang 2, Haiou Yang 1, Menghua Song 1 and Weidong Huang 1

Source: http://mdpi.com/



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