In the aluminum industry, production often faces various surface defects such as false joints, scratches, mechanical lines, black lines, bumps, and severe welding seams. These issues can lead to color differences or black bands, resulting in product rejection and irreversible damage. One of the main reasons for low welding force is insufficient extrusion force, which may be caused by factors related to the mold or the extrusion process itself. The extrusion temperature and speed play a crucial role in this. High extrusion temperatures help with metal diffusion and bonding, but they also intensify the die bonding phenomenon. Additionally, high temperatures promote grain growth, which can result in thicker weld microstructures. When the extrusion speed is too high, the deformation work increases, causing the metal temperature to rise further. This, in turn, reduces the pressing force and lowers the welding strength. Another issue arises when graphite products are used as slip-out stations, as oxidation on the contact side can lead to black bands on the profile.
The failure of hot extrusion dies in aluminum alloy production is typically caused by cracking, wear, corrosion, overheating, and thermal fatigue. The lubrication conditions of the mold significantly affect its service life. During the extrusion of aluminum and its alloys, it's essential to use lubricants to reduce friction between the metal and the barrel wall, the piercing pin, and the mold surface. This helps minimize adhesion and tooling wear.
Historically, due to limitations in material development and improper lubricant usage, surface contamination was common. Lubricants could sometimes flow into the center of the product, creating a more noticeable "squeeze" effect. As a result, "lubrication-free extrusion" has been widely adopted in the extrusion of bars and profiles. For tubes and hollow profiles, only the die and piercing needle surfaces are lubricated. Recently, many countries have focused on extruding large and complex hard aluminum profiles using extruders with limited pressure while increasing extrusion speed to achieve more uniform structural properties. Significant research has been conducted in this area, and breakthroughs in tooling design and lubricant technology have led to major advancements in lubricated extrusion. Among these developments, JONYE high-temperature lubricant has emerged as a key solution.
Especially in high-temperature extrusion processes, welding quality issues and mold surface problems are common. Applying JONYE high-temperature lubricant at room temperature can prevent rust on the working surface. After prolonged preheating, the surface of the protective work belt remains free from decarburization and oxidation, maintaining its original hardness without forming soft spots or soft zones. This enhances the lubrication between the die and the profile, reducing friction and preventing die blocking or crushing. As a result, the production process becomes smoother, the welding quality improves, ripples are minimized, and the product’s surface becomes smoother. It also prevents adhesion, sticking, and aluminum buildup, reduces mold repair frequency, and extends the mold's service life.
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