Cast-In Hypereutectic Aluminum Liners for Engine-Blocks

A series of experimental trials was carried out to study the metallic bond produced when hypereutectic aluminum liners are cast-in hypoeutectic aluminum engine-blocks. The samples were cast in a rig that reproduces the conditions encountered during production of engine-blocks made of a type 319 aluminum alloy. The surface roughness of the liners was modified by sand blasting before casting. Some of the liners were cast after coating their surface with an amorphous carbon layer (soot) to study its effect on the metallic bond. The samples were sectioned and prepared for their examination and testing. It was found that soot does not allow the development of a metallic bond between liner and body and that the force required to remove the liners depended on such a bond; in any case, the force required to remove cast-in liners, even without bonding, was higher than that needed for removing gray iron press-in liners.