What is the allowance of the dewaxing casting process?
- 2020-01-03-

  Lost wax castingThe craft is developed from the ancient casting craft. In the late Neolithic period more than 5,000 years ago, ancient Chinese craftsmen widely used the lost wax casting process in the production of bronzes. According to the characteristics of plasticity and thermal evaporation of beeswax, the craftsmen at that time first carved the beeswax into a wax mold of the required shape, then wrapped the clay outside the wax mold and reserved a small hole, and baked it after drying to vaporize the wax mold. At the same time, the clay becomes a ceramic shell, and the female mold of the wax mold is left on the inner wall of the shell. At this time, the molten metal is injected into the shell along the small hole, and the shell is broken after cooling to obtain the required metal casting billet. The basic principles of modern lost wax casting skills are the same, but they are becoming more complicated and sophisticated. This is mainly reflected in the stricter requirements for the precise position of the wax model. In modern technology, the acquisition of wax mold is not only the direct carving of wax, but also the female mold can be obtained by molding the metal original mold (plate) with silica gel, and then the wax mold can be obtained by injecting wax from the silicone female mold. The casting material is no longer clay, but instead cast plaster. Such products are much more precise than ancient castings.

  Guangdong Stainless Steel CastingProcess allowance: In order to ensure the sequential condensation of castings, sometimes it is necessary to increase the allowance of a certain part of the casting. This kind of excess beyond the rated part of the machining allowance is called the process allowance.

Dewaxing casting casting size service: see GB/T6414-1999

Dewaxing casting fillet: The casting fillet radius R (mm) can generally be calculated according to the following formula: where, 'is the thickness of the adjacent wall of the casting. ) Can be calculated as follows:

Dewaxing casting slope: The size of the casting slope of the casting is related to the relative position between the surface of the casting and the metal mold. When the casting is cooled, the surface that has a tendency to separate from the surface of the metal mold should be given a smaller casting slope, and the stone row is dewaxed casting. When the casting is cooled, the surface of the metal mold or core tends to be tight, and the bridge head is dewaxed. Should be given a larger slope. example:Coffee machine accessoriesFor the holes and recesses, the casting slope should be larger, generally 2°-7°, 2°-3° for the unmachined surface, 3°-7° for the machined surface