Li C.-B.,Central South University |
Li C.-B.,The Key Laboratory of Nonferrous Metal Materials Science and Engineering of Ministry of Education |
Liu S.-D.,Central South University |
Liu S.-D.,The Key Laboratory of Nonferrous Metal Materials Science and Engineering of Ministry of Education |
And 4 more authors.
Cailiao Kexue yu Gongyi/Material Science and Technology | Year: 2012
To investigate the effect of hot rolling on hardenability of 7055 aluminum alloy, the properties and microstructure at different cooling rates determined by end-quench method, hardness test, optical microscopy and transmission electron microscopy were studied, and the results showed that the hardenability was decreased significantly after hot rolling with the hardened depth deceasing from about 100 mm to 45 mm. This is because the number and size of η equilibrium phase formed during slow quenching are changed by hot rolling. Hot rolling increases the nucleation sites for η equilibrium phase, and introduces a number of dislocations which prompt growth of η equilibrium phase. As a result, in the hot-rolled and solution treated alloy, more η equilibrium phase particles with larger size are formed during slow quenching, which decreases the number of strengthening η' precipitates after aging. Thus the drop in the hardness with the decreasing of cooling rate is increased, which decreases the hardenability.