Brass is a Copper-Zinc alloy which is harder than copper and less hard compare to bronze.
Copper Nickel alloys as name suggests Nickel, major alloying element, is added to the Copper.
Gunmetal Gunmetal is a Copper-Tin-Zinc alloy.
Bronze Bronze is a Copper-Tin alloy. The casting alloy has tin content between 9-12%. Increasing Tin content decreases conductivity but increases the hardness.
Leaded Bronze Leaded Bronze is a Bronze alloy with a higher Lead contents.
Aluminium Bronze Aluminium Bronze is Copper-Aluminium alloy where Aluminium (5-11%) is the main alloying element added to Copper.