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:
Squeeze-cast 20vol%SiCw/2024 composite was processed by rotary-die equal-channelangular pressing (RD-ECAP) and tensile-tested at elevated temperatures. RD-ECAP does notrequire billet removal and reinsertion between ECAP passes and can produce large cumulativedeformation of type A in the billet at a controlled extrusion temperature. Tensile specimens weremachined from the RD-ECAP processed billets along the longitudinal direction. 16 RD-ECAPpasses at 623 K produced an average matrix grain size of about 0.8 μm in the composite. The ECAPprocessed 20vol%SiCw/2024 composite exhibited 330% elongation to failure when tested at 783 Kand the high strain rate of 1.17×10-1 s-1. The values of strain rate sensitivity exponent of theSiCw/2024 composite determined over the strain rates between 10-2 and 1.0 s-1, was 0.39, 0.47 and0.53 at 763, 773 and 783 K, respectively. The grain sizes of the aluminum alloy matrix in thecomposite after superplastic deformation increased from 0.8 μm to be about 1.5 μm. There was nocavity found within the uniformly deformed area. The apparent activation energy for thesuperplastic deformation of the 20vol%SiCw/2024 composite was determined to be 284 kJ·mol-1
Type of Medium:
Electronic Resource
URL:
http://www.tib-hannover.de/fulltexts/2011/0528/02/15/transtech_doi~10.4028%252Fwww.scientific.net%252FMSF.539-543.2934.pdf
