Effect of Yb Additions on Microstructures and Properties of High Strength Al-Zn-Mg-Cu-Zr Alloys
The effect of 0.30 Yb (mass fraction,%) additions on the microstructure and properties of high strength Al-Zn-Mg-Cu-Zr aluminum alloys has been investigated by TEM, optical microscopy, hardness and electric conductivity measurement, tensile test, stress corrosion cracking test. The results show that the ytterbium additions to high strength Al-Zn-Mg-Cu-Zr aluminum alloys significantly inhibited recrystallization during solution treatment. The tensile and yield strengths, elongation, hardness, electric conductivity and stress corrosion cracking resistance of the Yb-containing alloys are improved compared to the alloys without Yb additions. By Yb additions, the critical stress intensity (KISCC) is enhanced from 7 MPa·m1/2 up to 14.5 MPa·m1/2 with the improvement of the strength and ductility. The mechanism for the property improvement from Yb additions has been discussed.
Yafang Han et al.
K.H. Chen et al., "Effect of Yb Additions on Microstructures and Properties of High Strength Al-Zn-Mg-Cu-Zr Alloys", Materials Science Forum, Vols. 546-549, pp. 1021-1026, 2007