Publication Date:
2019-07-20
Description:
Correlative high resolution transmission electron microscopy and energy dispersive X-ray spectroscopy are used to study deformation-induced planar faults in the single crystal superalloy MD2 crept at 800C and 650 MPa. Segregation of Cr and Co at microtwins, APBs, CISFs/SISFs and CESFs/SESFs is confirmed and quantified. The extent of this is found to depend upon the fault type, being most pronounced for the APB. The CESF/SESF is studied in detail due to its role as a precursor of the microtwins causing the majority of plasticity under these conditions. Quantitative modelling is carried out to rationalize the findings; the experimental results are consistent with a greater predicted velocity for the lengthening of the CESF/SESF { compared with the other types of fault { and hence confirm its role in the diffusion-assisted plasticity needed for the microtwinning mechanism to be operative.
Keywords:
Metals and Metallic Materials
Type:
GRC-E-DAA-TN57666
,
European Symposium on Superalloys (Superalloys 2018); Sep 09, 2018 - Sep 13, 2018; Oxford, England; United Kingdom
Format:
application/pdf
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