What are the disadvantages and advantages of alloys?

Advantages of alloys:

-high strength-to-weight ratios

-a wide range of different alloys, to suit a range of different uses

-low density

Disadvantages of alloys:

-No fatigue limit

-prone to corrosion, so need protective finishes, particularly magnesium alloys

-Many alloys have limited strength, especially at elevated temperatures magnesium alloys have low strength