ANALYZING THE YIELD STRENGTH OF SUPERALLOY SINGLE CRYSTAL DD407 AT 760℃ BY LCP-MODEL
Received date: 2012-10-19
Revised date: 2013-01-15
Online published: 2013-04-11
The yield strength, corresponding to 0.2% plastic deformation, of superalloy single crystal DD407 with 22 different orientations were measured at 760℃ to investigate the orientation dependence of yield strength for this superalloy. The facets of fractured specimens were observed by scanning electron microscopy and their crystallographic characters were identified with the aid of X-ray diffractometer. The results indicated that specimens near [111] were deformed by cubic slip systems,and the rests were deformed with octahedral slip systems. The orientation dependence of yield strength was established and analyzed by an LCP-model. It showed that the yield strength of DD407 specimens deformed by octahedral slip accorded with LCP-model, whereas those deformed by cubic slip, such as [111] crystals, deviated from LCP-model. A close inspection of the LCP parameters suggests that, in dual-phase γ/γ’ crystals, the effect of γ matrix must be responsible for the positive sign of b2 term which is negative in mono-phaseγ’ crystals.
ZHANG Longfei , YAN Ping , ZHAO Jingchen , HAN Fengkui , ZENG Qiang . ANALYZING THE YIELD STRENGTH OF SUPERALLOY SINGLE CRYSTAL DD407 AT 760℃ BY LCP-MODEL[J]. Acta Metall Sin, 2013 , 29(4) : 489 -494 . DOI: 10.3724/SP.J.1037.2012.00624
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