The semi-solid slurry of 7075 aluminum alloy was prepared with an inverted cone channel.The experimental results indicate that the semi-solid 7075 aluminum alloy slurry with satisfied quality can be produced with the inverted cone pouring pipe

and there exhibits only a thin layer on solidified shell inside the pipe with the pouring temperature of 660 ℃～690 ℃ and the inner wall conicity of 2°～6°.With a fixed conicity

the equivalent size of the primary α-Al grains is decreased and the shape factor is increased with decreasing in pouring temperature.With a given pouring temperature

the equivalent size of the primary α-Al grains is decreased and the shape factor is increased with the increase of conicity.The experimental results also show that a large number of nuclei of primary α-Al grains are formed on the inner surface of the inverted cone pipe

and most of them can be separated from the inner surface as well as grain ripen in the containing crucible during the slurry preparation

which is responsible for the generation of fine spherical primary α-Al grains.