Although die casts made by the die casting
technology can meet operating requirements of most parts, the problem of shrinkage in the die casts is difficult to be solved. The development of extrusion casting technology has greatly improved the above problems, and there are some new technologies in recent years, including double extrusion casting technology, semi-solid extrusion casting technology and multi-extrusion casting technology.
1. Double extrusion casting technology
Double extrusion casting is also known as "secondary extrusion", and the technology can effectively solve shrinkage defects of thick and big parts. For example, a Japanese company named UBE Industries Co. Ltd. uses a VSC vertical extrusion casting machine to produce aluminum wheels. For the thick and big parts of aluminum wheels which can easily have shrinkage problems, UBE Industries Co. Ltd. adopts VSC18000kN large-scale extrusion casting machines and uses vacuum technology to discharge the air in the cavities, further reducing the occurrence of the blowhole phenomena of die casts.
2. Semi-solid extrusion casting technology
Semi-solid extrusion casting technology is also a new technology which develops rapidly at home and abroad. Japanese UBE Industries Co. Ltd. studies semi-solid extrusion casting technology of VSC and HVSC extrusion casting machines and can produce die casts
through this technology. Toshiba Corporation adds a cooling temperature control system to an extrusion cylinder and makes the whole production process of semi-solid extrusion casting come true based on DXHV and DXV extrusion casting machines.
3. Multi-extrusion casting technology
Multi-extrusion casting technology can apply pressure to the specific direction based on the requirements of the parts, which overcomes shortcomings of one way pressure in the traditional extrusion casting. This technology effectively solves great uneven wall thickness, complicated structure, overall or partial shrinkage problems of parts.
Dutch Prince Machine, French JL, American Grandville and Michigan developed the "full cylinder" extrusion casting technology and produced a lower crankcase with good performance for Ford Motor Company. These new research and technological development have greatly contributed to the improvement of die casting