Effect of Microstructure on Mechanical and Corrosion Properties of 2A14 Aluminum Alloy Wheels.

The microstructure in different regions of 2A14 aluminum alloy wheel and their effects on both mechanical properties and corrosion properties were studied by electron backscatter diffraction (EBSD), field emission scanning electron microscope ( SEM), transmission electron microscope ( TEM), room temperature tensile test, immersion test and electrochemical polarization. The results show that the grains size of the center and 1/4 layer of the 2A14 aluminum alloy wheel are 113 and 54 µm respectively, and the recrystallization fractions are 16% and 36%. The intermetallics and the aging precipitates in the 1/4 layer are larger than those of the center and the number density of the two aging precipitates (ϑ' and Q phase) is about twice that of the center. The lower quenching cooling rate of the center of the 2A14 aluminum alloy wheel reduces the number of precipitates and the dislocation resistance. Therefore it is mechanical properties are worse than 1/4 layer. The number of intergranular corrosion sites and the depth of intergranular corrosion in the center are smaller than those in the 1/4 layer due to the lower intermetallics content [ABSTRACT FROM AUTHOR]