FOSECO launched a new range of coatings for producing cylinder liners by the centrifugal casting process. Centrifugal casting uses centripetal force to distribute molten metal in mold, typically metered into the mold or die. Proponents recommend the process for producing castings with high material soundness — cylinder liners, for example.
The SPUNCOTE SP coatings were especially developed by Foseco to influence the cast surface texture of a cylinder liner so that it can be cast directly into an aluminum cylinder block without the need for external machining.
Specific formulations are available to achieve surface textures that range from a fine roughness through a spine-like structure, to a novel, wormlike appearance.
“When casting around a gray iron cylinder liner it is essential that an intimate physical bond is created between the aluminum and iron after solidification,” Foseco notes, “as the creation of voids will lead to poor thermal transfer and the risk of slight movements in operation, reducing the life expectancy of the block.
“Through the use of SPUNCOTE SP coating and the associated application technology, surface textures can be created that minimize the creation of voids regardless of the aluminum casting technology,” the developer continued; “cylinder liners can be produced that can be effectively used for sand casting, high-pressure, low-pressure or gravity diecasting.”
Other advantages credited to the new coating include:
• The refractory filler is highly resistant to the high temperature of the liquid iron and has good insulating properties;
• The coating has optimal drying properties when applied to the hot die, without spalling or the formation of craters or blisters, ensuring the cast surface is free from pin-holes, blemishes, or entrapped coating material;
• Excellent releasing properties help to avoid problems during the removal of the cylinder liners from the die. The release properties are not only important for productivity but also extending the in-service life of the die;
• The coating is ready for use, which means that no further additions (such as soap) are needed before application.
Learn more at www.foseco.com