(1) Development history of foreign FMC casting
The first place where the research onbegan was the United States. In 1956, the American H.F.Shiroyer applied for a patent. The casting method he invented was solid casting, that is, making parts with foam pattern, then making sand with adhesive sand. At the beginning, this method is more suitable for the casting of handicrafts and large pieces in small batches. The most typical example of this casting method is the alloy steel stamping die cast by Ford, which weighs 15000 pounds and belongs to commercial castings. Professor a. wittmoser of Aachen University of technology in Germany introduced this technology from the United States in 1961, and Professor a. wittmoser then applied the full mold casting to industrial production and cooperated with Hartman company.
(2) Development history of LFC casting abroad
Foreign LFC method was initiated by M. Flemings and H.F. Taylor, professors of MIT, an artist and A. Duca and others. They use foaming resin to make art models, then bury the models in bonded sand, compact the bonded sand, and finally pour various alloys to obtain various works of art. Therefore, M.C. Flemings and others have become the inventors of this casting method. This method is called lost foam casting, that is, lost foam casting, or LFC for short. Then, based on the casting method of M.C. Flemings and others, T.R. Smith proposed to use sand without binder to replace sand with adhesive. This casting method was patented in the United States and began to use this method to produce castings in large quantities in 1964. Because the above casting method uses dry sand without adhesive, it often leads to box collapse. Therefore, due to the emergence of these phenomena, Professor a. wittmoser used a new material to replace dry sand as molding material in 1967. This new material is magnetized iron shot, which also needs to use magnetic field, With the action of magnetic field, iron pellets can stick together. This method is called magnetic mold casting, but the application of this method has requirements for the size of castings, so it has great limitations.
(3) Development history of V casting abroad
In 1971, V method obtained the invention patent in Japan. V method is the vacuum film sealing molding method, so Japan is the birthplace of V method casting. V method casting is to replace the role of adhesive with pressure difference on the basis of LFC method casting. This pressure difference is to seal the sand box with plastic film, and then extract the gas in the sand box with true gas system, so that the sand mold is not easy to collapse.
(4) Development history of replica CS shell casting abroad
The origin of the foreign replica CS shell casting method is the UK. This method is mainly combined with the shell making technology replica ceramic shell process. We know that the process of investment casting is to make the casting model with wax, then coat it with mud and bake it to form the ceramic mold. The difference between this process and the investment mold is that, Instead of using the foam pattern to replace the wax model in the investment, the foam pattern is removed by the principle of investment casting, and finally the lost foam casting is formed.