Lost foam casting process technology, usually referred to as EPC, is also called gasification mold casting or full mold casting in the industry. The basic principle of the process is to combine the wax model or foam model similar to the size and shape of the preformed casting into a model cluster, then brush the refractory coating on the outer surface of the cluster, then heat it and then dry it, then bury it in dry quartz sand to form the shape, and then pour it under negative pressure to make the preset model fast gasification, and the high temperature liquid metal occupies the prefabricated model position. It is a new casting method to form castings after solidification and cooling of high-temperature liquid.
Lost foam casting is a new casting method with high forming rate, small machining allowance and accurate blank forming. The advantages of this new casting method are that it does not need to take the prefabricated sample mold out of the mold cavity. At the same time, there is no parting line in the external view of the product, and it is not necessary to use sand core in the process of lost foam casting, Therefore, there are no casting defects such as burr, burr and draft angle on the formed products, and the dimensional deviation caused by the combination of core and sub box can be reduced.
After casting, the machining allowance can be reduced to 1.5mm to 2mm. Due to the reduction of machining allowance, the cost related to subsequent processing consumption of mechanical manufacturing can be reduced. Compared with the traditional sand casting method, the machining amount can be greatly reduced by 40% to 50%. This technology was first invented by H.F. Shroyer of the United States in 1958. Later, it was continuously improved through scientific research by relevant technicians in Germany, Japan and Italy. After the 1980s, this technology developed rapidly all over the world. In the 1980s, China also introduced lost foam casting production technology. In recent years, the rapid development of lost foam casting process in China has achieved very optimistic results. A foundry machinery factory in Luoyang, Henan, China has done well in the field of lost foam castin R & D, and its products have been exported to all over the world. In addition, Tsinghua University, Huazhong University of science and technology and other colleges and universities have made valuable contributions to the R & D of lost foam technology.