Root-cause Tree: Tearing, Wrinkling & Punctures
起凸缺陷根因树：撕裂、皱褶与锤穿
标签：开裂, 皱褶, 锤穿, 根因分析
起凸废品沿三条分支诊断：皱褶——口缘压缩失稳起皱，继续锤打会把折叠锤进壁内，必须在每两三圈后、皱褶定型前退火（紫铜与银均 600–650℃，空冷或水冷皆可）；撕裂——多因壁厚已锤至 1 mm 以下仍继续收缩口缘，或锤击点太靠边，应改为内侧加支撑成形；锤穿——锤面边缘太锐或再生铜板夹杂所致，锤面倒圆并更换合格板材。坚持记录每件的退火次数、圈数与最薄壁厚，十件数据就能分清是手法问题还是材料问题。
Diagnose raising scrap along three branches: wrinkling — compressive buckling at the rim; hammer on and folds get driven into the wall, so anneal every two or three rounds before wrinkles set (copper and silver 600–650°C, air or water cool). Tearing — usually the wall is already under 1 mm while contracting the rim, or blows land too near the edge; switch to forming with inside support. Punctures — over-sharp hammer edges or inclusions in cheap recycled sheet; radius the face and buy certified stock. Logging anneal counts, rounds and thinnest wall per piece separates technique problems from material problems within ten pieces.