Aluminum-based sliding alloy and casting apparatus for the same

1. An aluminum-based sliding alloy containing

1 to 15 mass % of Si,

wherein Si precipitates in a form of particles in an observation field of the alloy, the Si particles having a maximum diameter of 0.01 to 7.5 μm and a total area of the Si particles having a diameter of not larger than 5.5 μm accounting for not less than 95% of a total area of the Si particles in the observation field,

wherein the alloy has an average regional area of all areas of the Si particles when measured by a region splitting method, the average regional area being not greater than 10 μm 2 .

2. The aluminum-based sliding alloy according to claim 1 , wherein the alloy has an average regional area of all areas of the Si particles when measured by a region splitting method, the average regional area being 5 to 10 μm 2 .

3. An aluminum-based sliding alloy comprising

1 to 15 mass % Si,

the Si being precipitated as particles in an observation field of the alloy wherein the Si particles have a maximum diameter of 0.01 to 7.5 μm, and

wherein the Si particles having a diameter of not larger than 5.5 μm account for not less than 95% of the total area of the Si particles in the observation field, and

wherein the alloy has an average regional area of all areas of the Si particles when measured by a region splitting method with the average regional area being not greater than 10 μm 2 .

4. The aluminum-based sliding alloy of claim 3 wherein the aluminum-based sliding alloy is a product of cooling a melt of Al or an Al alloy containing said 1-15 mass % of Si at a rate of 80 to 130° C. per second to a temperature of 550° C., and solidified.