Selection of casting methods in precision casting
What are the priority principles for casting method sel […]
What are the priority principles for casting method selection in precision casting?
What we should know about this knowledge is the priority of sand casting. According to statistics, in China or internationally, 60-70% of all castings are produced in sand type, and about 70% of them are produced by clay sand. The main reason is that sand casting has lower cost, simple production process and shorter production cycle than other casting methods. Therefore, the engine cylinder block, cylinder head, crankshaft and other castings like the automobile are produced by the clay wet sand process. When the wet type does not meet the requirements, consider using a clay sand table dry sand type, dry sand type or other sand type. Clay wet sand castings can weigh from a few kilograms up to tens of kilograms, while clay dry castings can weigh up to tens of tons. Generally speaking, for medium and large castings, cast iron parts can be made of resin self-hardening sand type, and steel castings can be produced with water glass sand type, and castings with precise dimensions and smooth surface can be obtained, but the cost is high.
The casting precision, surface finish, material density, metallographic structure and mechanical properties of sand casting are often poor, so when these performance requirements of castings are higher, other casting methods should be used, such as investment casting (loss of wax). Casting, die casting, low pressure casting, etc.