What is silica sol precision casting?Why can silica sol be used for precision casting?

Silica sol (colloidal silica), also known as silicic acid solution, is a colloidal dispersion of amorphous silica aggregates in water.The silica sol has a wide range of water loss temperature, which will not only destroy its bonding strength, but also make its three-dimensional structure more stable, resulting in higher bonding strength.It is a good inorganic binder for precision casting.

In the 1960s, silica sol began to be used as a binder for precision casting.Since the 1990s, due to the increasing pressure of environmental protection, silica sol has gradually replaced the widely used hydrolysates of ethyl silicate, which are serious pollution and expensive.At present, polymer reinforced fast drying silica sol is widely used as binder in investment casting industry in the world.

Precision casting is the general term for the process of obtaining castings with precise dimensions.Precision casting is also known as lost wax casting.Its products are precise and complex, close to the final shape of the parts, without processing or a small amount of processing can be directly used.This is an advanced near net forming process.The process includes: the selection of appropriate investment materials (such as paraffin wax) to make investment;The steps of repeated impregnation of refractory coating (mainly silica sol) and coating of refractory sand, hardened shell and drying on investment die;The cavity is obtained by melting the inner die.Bake the shell to gain sufficient strength and burn off the remaining investment material;Metal materials needed for casting;Solidification cooling, peeling, sand clearing, get high precision finished products.machinery parts82-2


Post time: Mar-10-2021
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