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 molybdenum alloy TZM (Mo-0.5wt%Ti-0.08wt%Zr) is a commonly used structuralmaterial for high temperature applications. For these purposes a high strength at elevatedtemperatures and also a sufficient ductility at room temperature are being aimed. Precedinginvestigations revealed the existence of subgrains in hot deformed TZM. It was observed that withproceeding primary recrystallization and therefore with disappearance of subgrains the yield strengthdrops almost to a level of pure molybdenum. It is being assumed that the existence of a dislocationsubstructure has a pronounced effect on the yield strength of TZM. The aim of the present study wasto evaluate the subgrain and texture formation and also to estimate the dislocation arrangement withinsubgrains during hot deformation. Hence, TZM rods were rolled to different degrees of deformationat a temperature above 0.5 Tm. The microstructure of the initial material was fully recrystallized.Texture formation, misorientation distributions and subgrain sizes were analyzed by electronbackscattering diffraction (EBSD). Mechanical properties were characterized by tensile tests at roomtemperature and up to 1200°C. It was revealed, that with increasing degree of deformation a distinctsubstructure forms and therefore yield strength rises. Consequently, the misorientation betweenadjacent subgrains increases, their size decreases and a 〈110〉 fibre texture develops. To estimate theinfluence of texture on strength of TZM the Taylor factors are calculated from EBSD data
Type of Medium:
Electronic Resource
URL:
http://www.tib-hannover.de/fulltexts/2011/0528/02/15/transtech_doi~10.4028%252Fwww.scientific.net%252FMSF.539-543.2725.pdf
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