For snow on summer low altitude climbs where the snow is always soft, just about any ice axe will work. This includes aluminum heads.
If you are going up anywhere you think there will be harder ice, like say a gully on north face at a fair amount of altitude, where either due to a cold night or cold day there will be hard ice then you will need a REAL ice axe. Aluminum need not apply as its not hard enough to hold its edge. Even Steel ice axes wear away their nose fairly quickly on ice and will be dull in short order.
By real, I mean an axe with Weight as well. For instance those who go vertical ice climbing prefer an ice axe with a very heavy head, not shaft, but head. you need said weight for the ability of the pick to stick. We are talking 2+lb ice axes.
For anything say like continuous 45 degree super hard snow or ice climbing in a gully you hadn't planned on crossing or climbing you will wish you had these heavy axes as it is far more efficient to climb with them. You swing once instead of twice or thrice. You will move far faster, and be less tired with a heavy axe compared to a junky light weight axe that will simply bounce off the surface, or barely indent the surface.
Winter time I would never even contemplate taking an aluminum head ice axe into the mountains as it is quite possible to run into bullet hard ice in the winter time even though the majority is fluff on low altitude stuff. THE ONLY TIME an aluminum head ice axe is doable IMO is in the spring/summer on melting snow packs below night time freezing level.
Trying to "save weight" on your ice axe is cutting off your nose to spite your face unless its for only low altitude non north face summer flings. For instance most climbs in the PNW would be fine with a aluminum axe. Mt. Ranier or the North faces of the Pickets or say shucksan is asking for a death wish. Now if you look at the weather before hand and know with certainty you can get up and down in say 24hours and the weather is stable, sure go for it. If you get vacation on "x" days in July and don't have a choice of when you go, I personally would not even think of bringing a light weight ice axe as I would have no idea if the conditions would be favorable to such an implement.
PS. For sure there will be bullet hard ice on Denali west buttress even in the summer time. There are big sections of 45 degree stuff that always has bullet hard ice. Generally with fixed ropes though.
Personally, unless I wanted to only bring an ice axe for general hiking, I would not waste my money on a light weight ice axe as its a limited one trick pony. If I was on the PCT, I would bring an aluminum ice axe through the sierras. Not sure why else I would want one though.