Defect Identification and Mold End Corresponding Rectification Plan for Fluorescent Penetrant Testing (PT) of Aluminum Castings | Quality Inspection Matching for Overseas Customers
Fluorescent penetration PT detected linear and point defects, with 46% traceable to mold structure, surface condition, and process parameter issues.
Continuous linear fluorescence display is mostly caused by thermal fatigue cracks in the mold cavity, and linear grain defects are replicated on the surface of the casting.
Dispersed point fluorescence display is mostly caused by aluminum peeling, mold cavity pitting, release agent carbon inclusion, and oxidation slag entrapment.
The branched diffusion fluorescence trace is mostly due to poor cold insulation fusion, and the oxide film at the front of the filling is not fused, which belongs to the mismatch between the filling flow rate and the mold temperature.
PT testing is concentrated at the root of the sprue and riser, mostly detecting shrinkage cracks, insufficient riser modulus, and premature cutting timing.
The position of fluorescent defects gradually increases with the number of molds, most likely due to the wear of the nitride layer on the mold surface and the continuous deterioration of roughness.
Low pressure die-casting molds (LPDC), reverse pressure casting molds (CPC), differential pressure casting molds for wheel hubs, low-pressure casting molds for wheel hubs, gravity casting molds, motorcycle wheel hub casting molds, structural component casting molds, aluminum alloy wheel hub molds, aluminum casting forming molds, low-pressure casting tooling molds. PT penetrant testing is mandatory for new energy orders in Europe and North America. Zhejiang Xinfeng Machinery's customer defect comparison table distinguishes mold problems, aluminum liquid raw material problems, and heat treatment problems to avoid blind mold modification. Many customers directly request to modify the cavity when PT detects defects, but in reality, it is only a matter of demolding spraying and charging timing, which can be solved by adjusting the process. Linear defects such as thermal fatigue cracks must be inspected, welded, and re nitrided on the mold; Priority should be given to adjusting the charging speed, mold temperature, and vacuum timing for cold insulation. The PT standard is graded, and the acceptance threshold varies greatly among different customers. Before accepting an order, it is necessary to confirm the customer's acceptance specifications to avoid delivery disputes. Google keyword "aluminum casting fluorescent penetrant test mold defect" accurately matches overseas factories that produce automotive parts and new energy aluminum components.
FAQ
1. Question: What is the priority for detecting linear fluorescent traces?
Answer: The thermal fatigue cracks in the mold cavity are replicated on the surface of the casting.
2. Question: What are the common causes of point fluorescence?
Answer: Sticky aluminum spots, carbon deposits, and oxide slag inclusions.
3. Question: What are the typical defects of branched fluorescent traces?
Answer: Cold insulation, insufficient fusion of oxide film at the front of aluminum liquid.
4. Question: Is there concentrated fluorescence detection at the root of the sprue?
Answer: Shrinkage cracks, check the riser module and timing of riser cutting.
5. Question: What do defects represent as the number of molds increases?
Answer: The nitride layer of the mold is worn and the surface quality continues to deteriorate.
6. Question: Do all PT defects require mold modification?
Answer: Not necessarily, some of them are related to process timing and release agent issues, which can be solved by adjusting the process.
