锌合金压铸件过度打磨质量问题案例
XSD Precision engineering resource for Zinc Die Casting Over-Polishing Quality Problem Case Study, covering TPMS buyer checks, validation points, sourcing risk, and project.
专业判断
XSD Precision 以品牌商、服务商、方案提供商和问题解决专家的身份，为 TPMS 与汽车精密工程项目提供从需求评审、工程验证到交付准备的专业支持。
XSD Precision engineering resource for Zinc Die Casting Over-Polishing Quality Problem Case Study, covering TPMS buyer checks, validation points, sourcing risk, and project.
Problem Description
The defect shown in the production photos is typical over-polishing: the operator removes too much material around the edge and contour area. The original crisp edge, step line or parting-line visual reference becomes rounded and unclear.
For decorative zinc die cast parts, polishing is not only a surface cleaning process. It directly affects product geometry, edge definition and customer-perceived quality.
Why Over-Polishing Happens
| Cause | What Happens | Quality Risk |
|---|---|---|
| Casting defect covered by polishing | Flow marks, parting flash, dents or carbon marks are removed by grinding instead of solving the upstream cause | Edges and lines are consumed while the real casting problem remains |
| No limit sample | Operators judge by experience without a clear OK/NG boundary | Different workers create different edge shapes |
| Wrong abrasive tool | Coarse belt, hard wheel or high-speed hand tool removes material too quickly | Local flat spots, rounded corners and uneven gloss appear |
| Uncontrolled pressure and time | Polishing force and contact time are not standardized | Good parts become NG parts during finishing |
| No protected edge design | Critical edge or decorative line has no fixture protection | Feature line disappears after repeated polishing |
How to Judge the Defect
Control Plan
- Create OK, warning and NG limit samples for edge definition, contour line and surface gloss.
- Define no-polish or light-polish protected zones around decorative edges, parting lines and assembly references.
- Replace free-hand heavy grinding with fixture-guided polishing where the edge must be preserved.
- Use finer abrasive sequence and reduce single-step material removal instead of one aggressive grinding operation.
- Record abrasive type, tool speed, contact pressure and polishing time for production repeatability.
- Fix upstream casting causes such as flash, flow mark, shrinkage or carbon mark instead of relying on polishing to hide them.
Engineering Recommendation
| Stage | Required Action | Acceptance Evidence |
|---|---|---|
| Mold trial | Confirm whether the edge and parting line are already clean before polishing | Trial samples and cavity-separated photos |
| Polishing setup | Lock abrasive grade, fixture, motion direction and maximum polishing time | Process instruction and operator training record |
| First article | Compare with limit sample before batch production | Approved first article photos and measurement data |
| Mass production | Inspect contour line, edge radius, mating gap and appearance consistency | Sampling record and defect Pareto |
Conclusion: over-polishing is a process-control failure. The right solution is to reduce upstream defects, protect critical edges, define limit samples and control polishing parameters. Do not use grinding as an unlimited repair method.
如需结合具体车型、产品型号、验证目标或制造准备要求进行评估，请向 XSD Precision 提供项目资料、图纸、规格、目标市场和验证边界。
提交项目资料与 RFQ资料适用边界与项目输入
本模块用于帮助读者将公开资料转化为可评审的项目输入，同时明确官网公开信息与受控项目文件的管理边界。
适用对象
面向汽车精密工程项目的采购、工程、质量、项目管理和供应链团队：用于在 RFQ 或量产准备前建立可审查的输入基础。
项目输入
2D / 3D 图纸、材料牌号、公差、表面处理、CTQ、工装检具、检验计划、样品验证、数量和交付条件。
输出边界
官网公开资料说明工程方法、质量边界和制造准备路径；客户图纸、规格版本、工艺参数、成本模型、检测数据和批准证据按 XSD Precision 工程文件与项目资料受控管理体系执行。