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 effect of welding, heat-affected zone (HAZ) simulation, and specimen orientation onthe microstructure and fatigue properties of 2195 Al-Li alloy was studied. HAZ simulation andGTA welding with a 4043 filler alloy resulted in a significant change in the microstructure. In theHAZ the primary strengthening phase, T1 (Al2CuLi), in the base alloy in T8 temper was replaced byTB (Al7Cu4Li) phase and voids/microcracks, and the fusion zone (FZ) consisted of T (AlLiSi) phaseparticles in the matrix, which consisted mainly of the filler alloy. The yield strength and fatiguethreshold of the 2195-T8 alloy were observed to be dependent upon the specimen orientation. TheHAZ simulation and welding led to a reduction in the tensile properties and fatigue strength. Whilethe post-weld heat treatment resulted in the re-precipitation of T1 phase in the HAZ, but no increasein the fatigue strength was observed due to the presence of microcracks. Fatigue crack initiationwas observed to occur at the surface in the base alloy in T8 temper, and at the internal defects afterHAZ simulation and welding. Fatigue crack propagation exhibited characteristic striations in theT8 alloy, and brittle cleavage-like feature after HAZ simulation and welding
Type of Medium:
Electronic Resource
URL:
http://www.tib-hannover.de/fulltexts/2011/0528/02/13/transtech_doi~10.4028%252Fwww.scientific.net%252FMSF.519-521.147.pdf
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