Lost foam casting originated in the United States. In 1956, American H.F.Shiroyer used EPS foam as wax mold material for lost wax precision casting for trial. In 1958, he made metal parts with the pattern of sand and foam sheet containing binder and published the technology in patented form. At that time, it was known as Cavitiless Casting Mold and Method of making same.
Lost foam casting was first used in the manufacture of works of art. In 1959, MIT began to study the lost foam casting technology, and applied this technology to the casting of works of art, successfully casting the Pegasus statue and nodular cast iron bell frame. It was not until 1962 that West Germany introduced technology from the United States that A. wittmoser, a professor at Aachen University of technology, developed and applied it in industry.
In the early stage of lost foam casting, molding sand containing binder was used for molding. Until the early 1960s, German H. nnellen did not use dry sand without binder for lost foam casting. American T.R. Smith obtained the patent of dry sand lost foam casting in 1964. Subsequently, R. D. hut1er, R. J. Pope in the UK and h. B. Dieter in the United States carried out systematic research on dry sand lost foam casting process. By 1967, many countries have adopted the lost foam casting process with clay sand and self hardening sand, and successfully produced thousands of tons of castings. However, the dry sand full mold casting without binder is still in the exploratory stage and has not been developed.
In 1967, a. wittmoser of Germany successfully studied the magnetic mold process by using magnetizable materials as molding sand and magnetic force as binder, and published it at the International Foundry Exhibition in 1968. Magnetic modeling method not only can not effectively solve the defects such as carburization, porosity and wrinkle of castings, but also limits the shape and size of products, and the process is complex, which is difficult to realize automatic production.
Germany’s E. kryzanowsky, Japan’s Akita Co., Ltd. and Nagano industrial testing institute invented the vacuum sealing molding method in 1967 and 1969 respectively. This method uses plastic film and vacuum negative pressure to seal and compact the mold. On this basis, the full vacuum sealed Mo1d proess was developed.
In 1970, the lost foam casting technology based on single piece production without binder dry sand realized mass production. This progress has attracted the attention of the casting industry in various countries to the lost foam casting process. The approaching patent right of lost foam casting and the improvement of casting quality requirements in the machinery industry after the oil crisis have further aroused the enthusiasm of all countries for this technology.