The effects of different solid solution time and temperature on the structure and mechanical properties of the Al-12Si-6Cu-1.5Ni-0.3Cr-0.8Ce-0.2La cast heat-resistant aluminium alloy were investigated by OM

SEM observation and tensile test.It is found that with the increase of secondary solution temperature and time

the primary silicon phase is passivated

and eutectic silicon and reticular phase are fused into granular or massive

and the tensile properties of Al-12Si-6Cu-1.5Ni-0.3Cr-0.8Ce-0.2La alloy are increased firstly and then decreased at room temperature and high temperature

reaching the optimum level with the secondary solid solution at 530 ℃for 2 h.With artificial aging at 200 ℃ for 6 h

and the tensile tests at room temperature and high temperature（300℃）

the tensile strength of Al-12Si-6Cu-1.5Ni-0.3Cr-0.8Ce-0.2La alloy reaches 342.0 MPa at room temperature and 159.9 MPa at high temperature（300℃）after 490℃×2 h+530℃×2 hand 200℃×6 hheat treatment.