When comparing metal and aluminum alloy, the better choice largely depends on the specific application and requirements. Generally, aluminum alloy is often considered superior due to its combination of strength, weight, and corrosion resistance. Aluminum alloys are typically stronger than pure aluminum and can be tailored to meet a wide range of mechanical properties. For instance, the addition of elements like magnesium, silicon, copper, and zinc can enhance strength, hardness, and durability.

According to a study by the Aluminum Association, aluminum alloys have a strength-to-weight ratio that is 2.5 times higher than that of steel, making them ideal for applications where weight reduction is critical, such as in the aerospace and automotive industries. Additionally, aluminum alloys are highly resistant to corrosion, which is a significant advantage in environments where exposure to moisture and chemicals is common. This corrosion resistance is due to the formation of a thin, protective oxide layer on the surface of the aluminum, which prevents further oxidation.

In contrast, pure metals like steel or copper may offer higher strength in certain forms, but they are generally heavier and more prone to corrosion. For example, steel is known for its strength but is significantly heavier than aluminum, which can be a disadvantage in applications where weight is a concern. Copper, while also corrosion-resistant, is softer and more expensive than aluminum alloys, making it less suitable for applications requiring high strength and cost-effectiveness.

Moreover, aluminum alloys are highly recyclable, with a recycling rate of over 90%, which is beneficial for the environment. This recyclability, combined with their lightweight and strength, makes aluminum alloys a preferred choice for many industries. In summary, while both metal and aluminum alloy have their merits, aluminum alloy often emerges as the better choice due to its versatility, strength, weight, and corrosion resistance.