Manufacturing and processing of powder metallurgy stainless steel fingerprint lock accessories

Firstly, it is necessary to determine the production process of fingerprint lock accessories: mold design and raw material determination - mold manufacturing - raw material mixing - mold installation and machine debugging production - pressing blank mesh belt furnace sintering (stainless steel materials need vacuum furnace sintering) - machining - deburring - rust prevention and oil immersion - inspection and qualified packaging.

The production and manufacturing of fingerprint lock accessories, mold design, and production process should be arranged in place. The iron based material for fingerprint lock accessories is generally FC0208 ordinary copper and carbon steel material, with a density of 6.8 or above. The other two types are FN0208 and FN0408 pre alloy powders, commonly known as AB alloy powder and AE alloy powder in the powder metallurgy industry. These two alloy materials are fully mixed by the manufacturer, and have good alloy properties, no segregation, stable composition, and can produce a pressing blank density of over 6.95. Warm pressing technology can also be used, and the pressing blank density can reach 7.2. After high-temperature sintering at 1120 degrees Celsius for 30 minutes, the metallographic bonding is strong and strong. AE alloy powder has a higher alloy content than AB alloy powder, and is widely used in labor-intensive transmission parts with high strength requirements, such as gears and ratchets. Powder metallurgy professionals must select materials appropriately based on relevant experience, material properties, and cost control.

If the fingerprint lock accessory material is made of stainless steel SS316L or SS304L, the design process and iron material are different. Firstly, the mold cannot be used interchangeably. The sintering expansion and shrinkage rate of iron based materials is usually around 3‰, while the sintering shrinkage of powder metallurgy stainless steel materials can reach about 15‰, which is quite different. Moreover, the precision of finished products made of powder metallurgy stainless steel is not easy to control due to its high shrinkage rate. Sintered billets have sufficient toughness and are easy to stick to the cutting tool, resulting in poor plasticity during secondary re pressing. Therefore, the production of powder metallurgy stainless steel has certain precision limitations. It's not a problem if it can be processed appropriately, but for those that cannot be processed (such as certain irregular parts), the accuracy must be within a controllable range before powder metallurgy can be used.

Secondly, the sintering process of seemingly simple powder metallurgy fingerprint lock accessories is also quite mysterious. When powder metallurgy pre alloy powder is sintered at a temperature below 1120 and less than 30 minutes in the high-temperature zone, the alloy properties of the product are not fully released, and its strength will be unsatisfactory. The iron-based powder metallurgy fingerprint lock accessories are basically made of FC0208 material and can be sintered normally. If it is a powder metallurgy stainless steel fingerprint lock accessory, an intermittent vacuum sintering furnace with a temperature of around 1250 degrees Celsius is required. After degreasing, heating, high-temperature sintering, cooling, and sintering, it takes at least 12 hours even if cooled by cooling gas. Vacuum sintering requires a relatively high vacuum degree, and requires a sufficient furnace of products to reduce the amount. When cooling with nitrogen gas, avoid excessive temperature, otherwise it is easy to nitride stainless steel products.

Finally, if the material of powder metallurgy fingerprint lock accessories is iron, rust prevention treatment should be done, and the surface treatment should be done with Dacromet or electroplating. Stainless steel fingerprint lock accessories are directly deburred for packaging inspection.