ISSN:
1662-9779
Source:
Scientific.Net: Materials Science & Technology / Trans Tech Publications Archiv 1984-2008
Topics:
Physics
Notes:
In this study, a newly developed duplex coating method incorporating plasmacarburization and CrN coating was applied to Ti-6Al-4V and its effects on the creep and hightemperature fatigue were investigated. The creep resistance was enhanced significantly by theduplex surface treatment. The stress exponent and the activation energy for creep of duplex-surfacetreatedTi-6Al-4V at 510~550°C were measured to be 8.0-9.5 and 230 to 280 kJ/mol, respectively.Both the stress exponent and the activation energy were not appreciably changed by surfacemodification suggesting that the creep deformation mechanism is not modified by the surfacetreatments, but rather dominated by the deformation of the Cu matrix. In the temperature range ofthe present study, the β phase acts as an athermal obstacle and increases the athermal strengtheningcomponent, which would increase the creep resistance and the stress exponent. Since the creepdeformation proceeds by overcoming thermal obstacles in the matrix, the activation energy is notappreciably modified by the presence of the β phase. The fatigue of duplex-surface-treated Ti-6Al-4V improved significantly over that its non surface-treated counterpart. The initiation of fatiguecracks is likely to be retarded more effectively by the presence of hard and strong Cr layers on thesurface, resulting in life time enhancement
Type of Medium:
Electronic Resource
URL:
http://www.tib-hannover.de/fulltexts/2011/0528/02/23/transtech_doi~10.4028%252Fwww.scientific.net%252FSSP.118.515.pdf
