The alloy of copper and nickel, called cupronickel, is used in low-denomination coins, often for the outer cladding. The US 5-cent coin called a nickel consists of 75% copper and 25% nickel and has a homogeneous composition. The alloy consisting of 90% copper and 10% nickel is remarkable for its resistance to corrosion and is used in various parts that are exposed to seawater. Alloys of copper with aluminium (about 7%) have a pleasant golden color and are used in decorations. Some lead-free solders consist of tin alloyed with a small proportion of copper and other metals.