Classification Of Forging Applications For RPM Technology
Precision forging is the most accurate of all forging methods. The precision is generally better than 0.5%, and the repeatability is good. The casting can be put into use with only a small amount of machining. Because the mold is used in a single use, it is possible to manufacture parts with complicated internal structures, and it is possible to produce parts that cannot be produced by casting or machining.
Although precision forging has many advantages, its production process is complicated and lengthy. The aluminum mold for pressing the wax mold generally takes several months depending on its complexity and size. After the aluminum mold is obtained, it takes several weeks to obtain the casting. These weeks are mainly used to make shells. In addition to time-consuming, precision forging is still very labor-intensive, and 50% to 80% of the cost is derived from labor. In addition, the amount of mold used in small batch production is spread to make the unit price expensive.
Rapid prototyping and precision forging are complementary, both of which are used in the manufacture of complex profile parts. If there is no rapid automatic forming, the production of mold is the bottleneck process of precision forging; however, without precision forging, the application of rapid automatic forming will have great limitations.
The application of rapid prototyping technology in precision forging can be divided into three types: one is the disappearing molded part (mold) process, which is used for small batch production; the other is direct shell method for small quantity production; the third is fast wax. Mold making, for mass production.
2. Fast forging
In the manufacturing industry, especially in aerospace, aerospace, defense, automotive and other key industries, the core components are generally metal parts, and most metal parts are asymmetrical in length, with irregular curved surfaces or complex structures, and the interior contains fine structures. . These parts are often produced by forging or dismantling. Fast forging is one of the most attractive methods for replicating metal parts using rapid prototyping as a master or transition mold. This is because the forging process produces parts with complex shapes.
In the forging production, the manufacture of the template, the core box, the wax type, and the die-casting mold is often performed by a machining method, and sometimes a fitter is required to perform the trimming, and the cycle is long and costly. From mold design to manufacturing is a complex process with multiple links. A slight mistake can lead to full rework. Especially for some complex castings, such as blades, impellers, engine blocks and cylinder heads, the manufacture of molds is a very difficult process. Even with the use of expensive equipment such as CNC machining, there are still major challenges in terms of processing technology and process feasibility.
The combination of RPM technology and traditional craftsmanship can enhance strengths and avoid weaknesses and achieve twice the result with half the effort. The wax mold is directly fabricated using rapid prototyping equipment, and the rapid forging process eliminates the need to open the mold, thereby greatly saving manufacturing cycle and cost. According to the traditional metal casting method, the mold manufacturing cycle takes about half a year, and the cost is several hundred thousand. With the rapid forging method, the rapid forging of the investment mold for 3 days and forging for 10 days greatly shortens the manufacturing cycle time.
3. Gypsum forging
Precision forging is often used to make steel parts from rapid prototyping. However, for low-melting metal parts, such as aluminum-magnesium alloy parts, gypsum forging, the efficiency is higher. At the same time, the quality of the casting can be effectively guaranteed, and the forging power is higher. In the gypsum forging process, the rapid prototyping is still a mold that can disappear, and the gypsum mold is thus obtained to obtain the desired metal parts.
The first step of gypsum forging is to make a lost mold by using a rapid prototyping piece, and then embedding the rapid prototyping lost mold in the gypsum slurry to obtain a gypsum mold, and then placing the gypsum mold into a cultivating furnace for burning. In this way, the rapid forming lost mold is decomposed by pyrolysis, and the whole disappears completely. At the same time, the plaster mold is dried and hardened, and the process generally takes about two days. Finally, the molten aluminum alloy is injected into the plaster mold in a special vacuum casting equipment. After cooling, the plaster mold is broken to obtain a metal piece.
This method of producing metal parts is very low in cost, and generally only 2% to 5% of the production of die-casting molds. The production cycle is very short, usually only 2 to 3 weeks. The function of gypsum castings can also be compared with precision castings, because the casting is done in a vacuum environment, so the function is even better than ordinary precision forging.