Evaluating Tooling Acceptance Criteria during Overseas Factory Acceptance Testing
Rigorous overseas tooling acceptance demands steady-state thermal runs, single-cavity Cpk validation, complete disassembly wear audits, and escrow-backed signoff.
Spark Spectrography
Meaning
Optical emission analysis uses an electric discharge to vaporize a small amount of material for chemical identification. During spark spectrography, the light emitted by the resulting plasma is measured to determine the exact elemental makeup of a metal sample. This technique is a standard tool in foundries and scrap yards for verifying alloy grades in seconds.
It stops being effective if the surface of the material is contaminated with paint, rust or heavy oils. The sample must be ground flat to provide a good electrical contact for the probe.
Plasma Emission
Every element in the periodic table produces a unique signature of light wavelengths when excited by high voltage. Specialized sensors in the spark spectrography equipment capture these signals and convert them into a percentage of mass for each component. This data allows metallurgists to confirm that the batch meets the strict requirements for aerospace or automotive parts.
Wavelength Detection
Portable units allow for on site inspection of raw materials without the need for a full laboratory setup. Performing spark spectrography at the receiving dock prevents the wrong grade of steel from entering the production floor. This speed is essential for maintaining a high throughput in a busy manufacturing facility.
Alloy Verification
Confirming the presence of trace elements helps ensure the long term performance of the finished product. If spark spectrography reveals high levels of sulfur or phosphorus, the batch may be rejected due to the risk of brittleness. This audit step protects the production yield by ensuring that only high quality materials reach the machining stage.