Defect: Blotchy Film & Local Burning
缺陷：膜层花斑与局部烧焦
标签：花斑, 烧焦, 电流密度, 搅拌
花斑多因预处理不匀或电流密度过高局部过热"烧焦"呈黑斑。对策：降低电压/电流密度（铜建议 0.5–2 A/dm²）、加强电解液循环搅拌、保证工件与对极平行且间距一致。烧焦处膜脆易脱，须褪膜重做：用 10% 硝酸浸除后重新活化。
Blotches come from uneven prep or local overheating "burn" at excessive current density, showing black spots. Lower voltage/density (copper 0.5–2 A/dm²), improve electrolyte circulation and stirring, keep work parallel to and evenly spaced from the counter-electrode. Burnt film is brittle—strip with 10% nitric acid, reactivate, redo. ---