Essentials Of Lost Foam Casting

- Apr 06, 2017 -

Essentials of lost foam casting

EPC casting (lost form casting) is a process of precision forming without allowance. It is characterized by the use of metal foam do disappear in appearance, neither type nor type core. The shape of the utility model is not provided with the die inclination, the casting has no flying edge burr, and the dimension error caused by the combination of the core blocks is reduced. The dimension precision and surface roughness of the casting can reach IT5 - IT7, Ra=6.3~12.5 m, close to the level of investment casting. Because of the dry sand, eliminated due to moisture, binder and additives have defects, casting rejection rate decreased significantly, significantly improve the quality of castings.

In the design of the new casting process, should be based on the characteristics of the casting, casting system with similar characteristics of the casting system for calculation. Each casting process has its own specific characteristics, and differ in thousands of ways. All these factors directly affect the accuracy of the design results of the gating system. To this end, the casting can be classified in some way. Model cluster combination can basically reflect the characteristics of castings, as well as the form of shrinkage of the casting. The section size of pouring system and casting size, model and each box combination of cluster number have relations.

The model exists in the casting process model of gasification need to absorb heat, so the disappearance of the pouring temperature casting process should be slightly higher than the sand casting. For the alloy of different materials, compared with sand casting, lost control in general is higher than that of sand casting casting pouring temperature of 30~50 DEG C. The heat of the metal liquid, which is higher than 30~50, can meet the requirement of model gasification. Pouring temperature is too low casting prone to casting defects, cold insulation, wrinkle skin and other defects. Casting temperature is too high to produce sticky sand and other defects.