Lost foam casting, also known as solid casting, is to form clusters of foam plastic models similar in size  shape to the castings, then apply paint  dry them, then bury them in binder-free dry quartz sand  vibrate tightly. When pouring under negative pressure, the model is vaporized,  the liquid metal occupies the position of the model. After it solidifies  cools, a casting is formed. This casting technology is a new type of casting technology in the 21st century  is called "green engineering in casting".

    As a new high-precision casting method, lost foam casting has the advantages of high precision, flexible design, high work efficiency,  environmental protection compared with other casting technologies. The castings obtained by the lost foam casting technology have a lower surface roughness than traditional casting technology,  the size accuracy can reach CT5 to CT7, which is close to the level of investment casting,  the machining time  remaining amount of processing are small.  because the casting has no flash burrs, it can also reduce the size error caused by the core block combination. In addition, the pattern of lost foam casting is made of foam, there is no parting surface  core, there is no drafting angle,  no drafting is required. If the components to be precision cast need to be processed  assembled  multiple parts, The foam patterns manufactured by pieces can be glued into an integral foam mold,  parts can be integrally cast.  the hole structure can be directly cast without the core, which is a great saving of time  cost in the production process  assembly process. The compact design of loose sand simplifies the production process of castings  improves labor efficiency. Dry sand has no binder  reduces the negative impact of sand processing. The high recycling rate can save costs,  it can be assembled in a box. The ability to pour multiple castings is beneficial to improve production efficiency  apply mass automated production. Then, when pouring through the lost foam casting technology, the discharge time of organic compounds is short, the location is concentrated, the discharge of organic compounds is less, it is easy to collect  handle, the noise  harmful gases are relatively small,  cleaner production can be realized.

    Worldwide, lost foam casting technology has been relatively mature in the production of cast iron, cast steel, aluminum alloy  other material parts. Lost foam casting technology can be widely used in cast iron  cast steel in my country. The current research focus is mainly on the special application of aluminum-magnesium alloy. The research on the lost foam casting of aluminum-magnesium alloys faces many technical  material problems. The first is the difficulty of filling. When the molten metal is filled  poured, the appearance will absorb a lot of heat  cause the front temperature of the alloy to drop, which is easy to form defects such as subcutaneous pores  cold barriers. Moreover, the casting temperature of the alloy is much higher than that of the ordinary cavity. The serious hydrogen absorption of aluminum alloy  the intensified oxidation  combustion of magnesium alloy can easily lead to defects such as pinholes  increased shrinkage in the casting. Secondly, use lost foam for aluminum-magnesium alloy

Casting technology requires low-temperature vaporized foam-like materials  high-strength  good-permeable coatings. This is also a key research topic. Since the 21st century, after continuous exploration  practice by scholars  all over the world, the special lost foam casting technology has made certain progress.