To give higher durability, ice axes are constructed of steel alloys. As for the shaft, the ones made of steel are more robust but with extra weight.
Nevertheless, if you’re starting and haven’t yet mastered your swing, the extra weight of an ice tool can be beneficial for penetrating hard ice.
On the other hand, lightweight shafts, which are aluminum made, are ideal for winter sports like ski climbing, glacier travel, and regular winter hiking, where being as light as possible is an important consideration.
Carbon composite shafts are used in more specialized ice axes and other ice equipment.
The material makes them extraordinarily light and versatile, but that comes with additional cost. Ice, steel, or aluminum tools are generally the best choices unless you want to cut weight on your trip.