Root-cause Check of Bubbles, Pinholes & Cracks
珐琅气泡、针孔与裂纹的根因排查
标签：气泡, 针孔, 裂纹, 烧成曲线, 排查顺序
三类缺陷按层次排查：气泡圆大且集中于底釉——胎体本身气孔或酸洗残酸未冲净，补烧一次底釉封孔；气泡细密于面釉——釉浆气泡未消（喷一层雾化酒精再入窑）或升温过快（780℃ 前控制 3–5℃/min）；针孔多为有机物污染（指纹、油雾）或过火；裂纹则查三处：釉与胎 CTE 失配、出炉骤冷、单层釉厚超过 1 mm（应分层烧）。排查纪律：先底釉后面釉逐层排除，每次只改一个变量；以 30 倍放大镜看气泡破口形态可判断气泡发生在哪一层。
Work defects layer by layer. Large round bubbles in the ground coat point to porous metal or trapped acid—refire a sealing ground coat. Fine bubbles in cover coats mean slip bubbles (mist with atomized alcohol before firing) or over-fast ramp (hold 3–5℃/min below 780℃). Pinholes track organic contamination (fingerprints, oil mist) or over-firing. Cracks implicate CTE mismatch, quenching on withdrawal, or single coats over 1 mm (build in layers). Discipline: eliminate ground coat first, change one variable at a time; a 30× loupe on bubble mouths reveals which layer outgassed.