ISSN:
1662-9779
Source:
Scientific.Net: Materials Science & Technology / Trans Tech Publications Archiv 1984-2008
Topics:
Physics
Notes:
In the case of transient liquid phase diffusion bonding with Ni base superalloy GTD-111,the bonding temperature was sustained at 1403K ~ 1453K. Thus, the microstructure of specimensheated at 1403K ~ 1453K was examined. In the raw material, γ-γ' eutectic phases, platelet η phases,MC carbide and PFZ were clearly observed in interdendritic regions or near the grain boundary andthe size of primary γ' precipitates near the interdendritic regions were larger than the core. Theprimary γ' precipitated in the dendrite core dissolved early in the bonding process. γ' precipitatednear the interdendritic regions were partially solubilized and their shape was changed. Thedissolution rate increased with increasing temperature. Phases in the interdendritic regions or nearthe grain boundary changed continuously with time at the bonding temperature. At a bondingtemperature of 1403K, the eutectic phases remained, but η phases were transformed from a plateletshape to a needle morphology and the PFZ region widened with time. The interdendritic region andnear the grain boundary became partially liquid at 1423K and fully at 1453K by the reaction of ηphases and PFZ. The interdendritic region and near grain the boundary became liquid and newphases which were mixed with η phases, PFZ and MC carbide crystallized during cooling at 1453K.Crystalline η phases were transformed from a rod shape to a platelet shape with increasing holdingtime
Type of Medium:
Electronic Resource
URL:
http://www.tib-hannover.de/fulltexts/2011/0528/02/22/transtech_doi~10.4028%252Fwww.scientific.net%252FSSP.118.65.pdf
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