Lost Wax Casting Steps, Advantages and Disadvantages

Lost Wax Casting, also known as Full Mold Casting, or Cavityless Molding Casting, refers to a casting method that combines molding with dry sand molding. The molten metal directly fills and replaces the space occupied by the original plastic mold, and directly obtains the required casting after cooling. The casting pattern is directly vaporized during the metal casting process, so the lost wax casting does not require mold removal.

The Steps of Lost wax Casting:

1- Use molds to produce casting patterns and casting gating systems

2- Bond the patterns and runners to form a mold bundle module

3- Dip paint on the module

4- Dry the paint

5- Put the module into the sand box and fill it with dry sand

6- Vibrate molding in order to fill the cavity with dry sand and then compact the molding sand

7- Pouring molten metal , forming the desired castings

8- After the castings have cooled, clean the castings. The dry sand can be recycled

Advantages of Lost Wax Casting

1- Lost wax casting can produce castings with complex shapes and complex cavities. Compared with the resin sand casting process, the more sand cores are replaced, the greater the profit margin of lost wax casting. The core competitiveness of lost wax casting is the production of difficult castings with complex inner cavities, such as engine block, engine head and box, etc. These characteristics make the superiority and economic benefits of lost wax casting fully appear, and realize the lightweight and precise casting.

2- Lost wax casting is a near-net shape casting method. The shape of lost wax castings can be comparable to resin sand castings.

3- Lost wax casting does not require mold removal, which provides greater freedom for casting design and casting process. In terms of process design, the lost wax casting process is first broken into parts and then spliced into a whole, and then the lost wax process is used for integral casting, so that the lost wax casting has the competitive advantage with the traditional sand casting.

4- The use of lost wax casting process can greatly reduce labor intensity, reduce the generation of solid waste, and the used dry sand can be recycled. This feature meets the requirements of energy saving and emission reduction, and has changed the harsh environment of traditional sand casting.

Disadvantages of Lost wax Casting

1- The surface quality and material properties of lost wax castings are easily affected by the decomposition products produced by gasification, which can cause problems such as carbon defects on the surface of iron castings and carbon increase on the surface of steel castings. At the same time, defects such as slag holes and pores are easily formed on the surface of the casting.

2- The harmful substances produced by gasification have serious pollution to the atmosphere. Therefore, the exhaust gas recovery and cleaning equipment of the lost wax foundry is very critical.

3- When using the lost wax casting process to produce thin-walled products, the deformation of the casting size is not easy to control.