ISSN:
1662-9752
Source:
Scientific.Net: Materials Science & Technology / Trans Tech Publications Archiv 1984-2008
Topics:
Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics
Notes:
The titanium affinity by oxygen is one of main factors that limit the application oftheir alloys as structural materials at high temperatures. Notables advances have beenobeserved in the development of titanium alloys with the objective of improving the specifichigh temperature strength and creep-resistance properties. However, the surface oxidationlimits the use of these alloys in temperatures up to 600ºC. The objective of this work wasestimate the influence of the plasma-sprayed coatings for oxidation protection on creep of theTi-6Al-4V alloy, focusing on the determination of the experimental parameters related to theprimary and secondary creep states. Constant load creep tests were conducted with Ti-6Al-4Valloy in air for coated and uncoated samples and in nitrogen atmosphere for uncoated samplesat 500°C to evaluate the oxidation protection on creep of the Ti-6Al-4V alloy. Yttria (8 wt.%)stabilized zirconia (YSZ) with a CoNiCrAlY bond coat was atmospherically plasma sprayedon Ti-6Al-4V specimens. Results indicated the creep resistance of the coated alloy was greaterthan uncoated in air, but nitrogen atmosphere was more efficient in oxidation protection.Previously reported results about the activation energies and the stress exponents valuesindicate that the primary and stationary creep, for both test conditions, was probablycontrolled by dislocation climb. Occurred a decreasing of steady state creep in function of thereduction of oxidation process, showing that Ti-6Al-4V alloy lifetime was strongly affectedby the atmosphere due the oxidation suffered by the material
Type of Medium:
Electronic Resource
URL:
http://www.tib-hannover.de/fulltexts/2011/0528/02/14/transtech_doi~10.4028%252Fwww.scientific.net%252FMSF.530-531.690.pdf
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