If you cut aluminum with your saw blade it is best if you use some kind of lubrication on the blade. This keeps the blade cool and also helps reduce aluminum buildup on the sides of the blade. A triple chip tooth style is used for cutting aluminum.
Wood cutting saw blades typically use a 4+1 style tooth form. this means a (left-right-left-right-flat) tooth pattern. Not good for cutting aluminum.
The triple chip blades will cut both, but if you cut aluminum and there is lube on the blade and then you go to cut wood, the dust will clog on the sides of the blades an act as though it is dull.
If you want the combo type blade make sure to clean the blades between wood and aluminum cutting.