Because the existence of Si reduces the activity coefficient of Al in the phase layer of FeSiAl 3 and decreases the number of aluminum atoms, supplied from molten Al to Fe 2Al 5 phase, the fast growth of Fe 2Al 5 phase is restrained.

• 由于Si降低了Al在FeSiAl3 相层中的活度 ,减少了从铝熔体向Fe2 Al5相供应的铝原子数 ,从而抑制了Fe2 Al5相的快速生长。