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:
Friction stir processing (FSP) has been employed for localized modification and control ofmicrostructures in NiAl bronze materials, which are widely utilized for marine components. Thethermomechanical cycle of FSP results in homogenization and refinement and the conversion ofmicrostructures from a cast to a wrought condition within stir zones in the material. However, thedirect measurement of stir zone temperatures, strains, strain rates and cooling rates is difficult due tosteep gradients and transients in these quantities, and this is an impediment in the assessment ofFSP-induced microstructures and properties. Quantitative microstructure analyses following FSP ofcast NiAl bronze materials have been used to develop estimates of stir zone thermomechanical cycles.The estimation procedures will be reviewed and the microstructure-based estimates will be comparedto results from computational models and embedded thermocouples measurements. Stir zonemicrostructures comprise a mixture of primary α grains and transformation products of the β thatformed during processing. Recrystallization in the primary α occurred due to particle-stimulatednucleation in this low stacking fault energy material. Factors that influence the distribution of strengthand ductility in the stir zone appear to include the mixture of microstructure constituents and gradientsin microstructure due to gradients in processing conditions
Type of Medium:
Electronic Resource
URL:
http://www.tib-hannover.de/fulltexts/2011/0528/02/15/transtech_doi~10.4028%252Fwww.scientific.net%252FMSF.539-543.3745.pdf
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