Microstructure and aging precipitation behavior of non-equilibrium solidified Al-4.73Mg-0.71Sc-0.33Zr alloy
The solidification microstructure evolution and precipitation behavior of Al-4.73Mg-0.71Sc-0.33Zr alloy under different cooling rates were studied using a combination of vacuum induction melting,copper mold spraying and aging treatment.The results show that the microstructure of the as cast alloy is composed of coarse α-Al matrix and Al3(Sc,Zr)micron-scale particles.After being sprayed into a copper mold,the average grain size of the non-equilibrium solidified(rapidly cooled)alloy decreases from 250 μm for as cast alloy to 7.5 μm,and the growth of Al3(Sc,Zr)particle phase is inhibited.After aging at 300℃for 45 min,a large amount of nano-scale Al3(Sc,Zr)phase is precipitated in the rapidly cooled alloy,and the micro hardness of the alloy increases from 79.86 HV0.2 to 121.95 HV0.2 which is 52.70%higher than the original rapidly cooled alloy.
NETL
NSTL
万方数据
