plating
/ˈpleɪtɪŋ; `pletɪŋ/ n[U]
1 thin covering of metal, esp silver or gold, on another metal 极薄的金属（尤指 金或银）的镀层或包层
The plating is beginning to wear off in places. 镀层有的地方已经磨掉了.
2 layer or covering esp of metal plates 层, 外层（尤指金属板）
protected with steel plating 用钢板防护的.