Microstructure evolution of semi-solid SiCp/AZ91D nanocomposite during isothermal heat treatment process

作者：Hu, Yong^*; Nan, Yu; Zhao, Longzhi; Liu, Dejia

来源：International Journal of Cast Metals Research, 2018, 31(6): 346-351.

DOI：10.1080/13640461.2018.1490066

• AZ91D
• magnesium alloy
• nano-size SiC
• nanocomposite
• semi-solid
• isothermal heat treatment
• microstructure
• mechanism

The microstructure evolution of semi-solid SiCp/AZ91D nanocomposite during isothermal heat treatment process in the mushy-zone was investigated. The results indicate that the nano-size SiC particles in composite are distributed uniformly and the grains are refined significantly by the addition of nano-size SiC particles. The semi-solid microstructure evolution experiences four stages during isothermal heat treatment process: the initial coarsening, structural separation, spheroidization and final coarsening. The grain size of the primary alpha-Mg phase decreases with the increasing of holding temperature. With the prolongation of holding time, the grain size of the primary alpha-Mg phase decreases at first and then increases. The optimum isothermal heat treatment parameter is 575 degrees C for 30min, under which the average grain diameter is 58 mu m and shape factor is 1.25.

• 出版日期2018-11-2
• 单位华东交通大学