Sand blasting and matter finishing are all widely used surface treatment processes for investment castings. They will be applied according to different requirements.
Below are brief instroductions of sand blasting finishing and matter finisning process. You can See the main difference between them.
1.Sand blasting treatment
By spraying wear materials(such as Carborundum, white corundum, glass bead) to investment rough casting surface with high speed, we can clear the oxided layer or rust surface of the rough investment castings, thus to improve and better the surface quality of the castings.
2. Matter finishing
Matter finishing is a kind of surface treatment process by dipping investment castings inside the mixture of pollution free pickling passivation paste and Inorganic Additives cleaning water. Then, to form a white layer to protect the investment castings from rust or corrosion. Such process is widely used for surface treatment of big and complex stainless steel investment castings. Such treatment can increase the non-corrosibility by 2 to 3 times. The anti rust property of stainless steel is mainly controlled by components of Chrome and Nickel. Matter finishing treatment can help to clean the surface of the casting surface, and also can concentrate the Chrome and Nickel components on the surface of the castings to improve the non-corrosibility of the castings.
According to the requirements of special castings, some customers also require to do the sand blasting process first, then do the matter finishing again. Just to better the surface property of castings.