For example steel base plated copper, nickel, chromium plating, low layer again tin bronze chrome, multi-layer nickel chrome plating nickel ferroalloy, chrome, and so on.
例如钢基上镀铜、镍层再镀铬、低锡青铜上镀铬、多层镍上镀铬、镍铁合金镀层上镀铬等等。
2
Coins made of copper, bronze and copper-nickel can change over time.
由铜,青铜和铜镍线制造的硬币可能随时改变。
3
Bronze (copper tin alloy) : its main feature is the addition of zinc nickel, corrosion resistance is very good.