Abstract:The constituent of precipitations phases of aged melt-spun AlMgCu ribbons was characterized by high-resolution transmission electron microscopy and microhardness test. The cooling rate of as melt-spun ribbon was estimated to be 1.60×10⁵ K/s from the empirical relation. The samples were aged at 200 °C for 16 h after solution treatment. Two precipitation phases, i.e. Al₂CuMg and abnormal amorphous SiO₂ were identified in the T6 melt-spun AlMgCu ribbon. The crystal structure and stoichiometric composition of Al₂CuMg phase are in good agreement with the reference results [WANG et al (2007; 2005)]. The combined experiments show that the formation of abnormal amorphous SiO₂ appears to be associated with the higher cooling rate in melt-spinning process and has no significant effect on the peak hardness.

Key words: AlCuMg alloy; melt spinning; precipitation; amorphous