The casting coating is composed of five basic components: refractory aggregate, carrier, binder, suspending agent and additives. With the development of technology, the casting coating has expanded from single sand prevention to multiple functions such as anti veining, sintering, porosity, leakage and sand hole, so as to meet the...
Coating is an important part of lost foam casting process and one of the key factors affecting the filling of liquid metal. The main functions of lost foam casting coating are as follows: (1) improve the strength and rigidity of the foam model to prevent deformation or damage during...
The composition of white corundum is α – Al2O3, its content is over 98% – 99%, the impurity is very little, the fire resistance is up to 2000 ℃ – 2050 ℃, containing Al2O3 385% – 90%, and it is brown crystal. The density of corundum is 3.85-3.9g/cm3, the...
1. Test results and analysis Four kinds of suspending agent: HB type suspending agent, Henan Xinyang bentonite, Hebei Zhangjiakou bentonite, Hubei marshan bentonite. Bentonite is the most commonly used suspension agent for water-based coatings. The most important function of bentonite is to form the structure of colloidal dispersion (coating)...
1. Refractory powder Commonly used refractory powders include zircon powder, brown steel jade powder, bauxite powder, quartz powder, mullite powder, chromite powder, magnesia powder, etc. zircon powder is an excellent refractory powder for cast steel. Zircon powder, namely zirconium decanoate powder, becomes zro267.2%, sio232.8%, melting point 2430 ± 20...
1.Properties of flow coating (1) The rheological properties meet the requirements of flow coating process. (2) Suitable coating thickness. Generally, the coating thickness difference should be ≤ 0.2mm. (3) With appropriate permeability. The diameter of sand particles with a surface depth of 1.5-2 times. Some of the following performance...
1.Flow coating equipment The flow coating equipment includes two parts: one is the gripping and rotating device of sand mold (core); the other is the flow coating machine. 2.Selection of power source for flow coating There are three methods: gravity method, air pressure method and pump pressure method. 2.1...
1. Brushing and swabbing 2. Dip coating 3. Spraying (1) The pressure of compressed air system is usually 500-600kpa. (2) The droplet velocity carried by the air flow is very high, and there are many rebound after impact on the surface, which affects the surface quality of the coating....
As an advanced casting method, lost pattern casting is paid more attention to and applied to the production of high manganese steel. At present, most coatings used by manufacturers are water-based corundum, zircon powder coatings or alcohol based magnesia powder coatings. The cost of using water-based corundum coating is...
1. Casting coating theory (1) The mechanism of anti sticking sand, including sintering stripping theory, bright carbon theory and so on. (2) In order to prevent the coating from cracking and peeling off, it is pointed out that the rapid thermal expansion of the coating and the sand mold...