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 extrusion rate and ratio on the Al3Zr induced dynamic recrystallization(DRX) that occurs during hot extrusion of RS-P/M Al-Zn-Mg-Cu-Zr alloys was investigated. Anincrease in the logarithm of extrusion rate promoted DRX and lead to a monotonic increase in thenumber of fine grains. Although DRX was also promoted and the grain size reduced by an increase inextrusion ratio from 10 to 20, the DRX behavior hardly changed, even when the extrusion ratioexceeded 20. However, with increasing extrusion ratio, the width of fibrous grain, i.e., theunrecrystallized region, decreased and the tensile strength increased to 879 MPa.When the extrusion rate and ratio exceeded 54 mm/min and 20, respectively, a marked graincoarsening occurred upon solution treatment, and the tensile strength tended to decrease, because ofthe high dislocation density induced by hot extrusion. By annealing at 563 K before solutiontreatment, it was possible to prevent grain coarsening, and thus prevent the strength decrease
Type of Medium:
Electronic Resource
URL:
http://www.tib-hannover.de/fulltexts/2011/0528/02/13/transtech_doi~10.4028%252Fwww.scientific.net%252FMSF.519-521.1479.pdf
