Precautions for aluminum stamping and sheet metal stamping
Aluminum is a softer material that is easily deformed under pressure and is one of the most suitable metal materials for stamping. Some aluminum alloy products require secondary or subsequent processing after stamping, such as polishing, wire drawing, and anodizing.
However, aluminum stampings are prone to tipping, crushing, scratching, deformation, etc. during stamping, requiring special attention and man-made protection measures.
1. In the manufacture of dies for aluminum stamping parts, special attention should be paid to the following points:
- The punching process is completed as much as possible without affecting the number of projects. For products with a large number of punched holes, even if you add one more process or station, you should put the punching holes behind.
- The aluminum material is soft and the mold is easy to block. Therefore, when designing the mold, it is necessary to reserve a gap of 10% of the material thickness on both sides. The straight edge of the knife edge is more suitable for 2mm, and the taper is suitable for 0.8-1°.
- When bending and forming, the aluminum material is prone to aluminum chips, causing spotting and indentation. It is preferable to apply a PE film on the aluminum material. In the case of a roller and plating, the forming block is preferably polished and hard chrome plated.
- Aluminum stamping parts that need anodized processing, if they are flattened or flattened by 180°. The product can not be completely pressed, and a 0.2-0.3mm seam is required to allow the acid to flow smoothly and in time. Therefore, a limit block must be made in this process, and the calibration die is higher than the mold.
- Aluminum material is brittle, easy to crack, especially in the case of reverse folding. Therefore, try not to do the pressing line. Even if you have to do the pressing line, you should make the pressure line wider and shallower.
- All the edges of the aluminum parts are required to be cut with a slow wire to prevent burrs and unloading. Aluminum parts are prone to high temperatures, so the hardness of the punch is required to be 60° or more, at least with SKD11 or higher, and low hardness punches such as D2 are not suitable.
2. The following points should be made during sheet metal stamping:
- If you want to stamp aluminum parts and reduce the defect rate, you must first do stamping quality of 5S:
- sort (Seiri)
- Set In Order (Seiton)
- Shine (Seiso)
- Standardize (Seiketsu)
- Sustain/Self-discipline (Shitsuke)
- Of particular note is the cleanliness. Molds, punching tables, lines and packaging materials must be free of sharp objects and dirt. Regular cleaning and rectification.
- If the product is found to have a large burr, it must be sent to the mold for repair and promptly to the result.
- aluminum parts are more prone to heat, and then accumulated together to become hard. Therefore, when punching and unloading, it is necessary to use the stamping oil to dissipate heat and help to blank the material, and then press it.
- Products with more punching need to be designed with cleaning tools (such as blowing, spraying or wiping) on the surface of the abrasive tool to keep the mold and product clean and not to be damaged by debris. If there is a top injury, the mold can be solved immediately to continue production.
- The flat block of the flattening die will produce aluminum chips, and the aluminum chips under the push block should be removed and cleaned every day after production.
(1) It takes 3-7 days to clean the punch or grind the punching edge to prevent the aluminum chip from affecting the quality of the product or affecting the efficiency. Damaged punches or edges should be replaced in time.
(2) For 180° bending and flattening products, the PE film must be torn open every 10-30 to check whether it is broken. Because there may be uneven composition during the discharge, especially when replacing the stamping material manufacturer, the first inspection must be strictly carried out.
Artical from: https://sipxmach.com/precautions-for-aluminum-stamping-and-sheet-metal-stamping/