Drying is the process of removing the carrier from the coating. The sand core should be dried in time after coating. Otherwise, the water (carrier) will react with the cold core resin group, which will reduce the coating strength of the sand core surface and cause quality problems in...
Suspensibility refers to the ability of coating to resist stratification and precipitation of solid refractory powder. On the premise of ensuring other properties, the higher the suspensibility, the better. Good suspension, uniform coating, no flow, simple operation, easy drying, high strength and no cracking after drying. There are many...
In order to effectively solve the problem of core breaking during sintering of water jacket and oil passage of cylinder block, ZHY casting’s water jacket and oil passage sand core are mixed with a certain proportion of ceramic sand (70 / 140 mesh). The ceramic sand is smooth and...
Uniform and stable coating composition is the basis to ensure the coating process performance, which belongs to static control for the user, and the stability of incoming materials is guaranteed by the coating supplier. However, due to the change of water evaporation, refractory powder segregation, viscosity and density, it...
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...