Composites including foam inserts designed for combustion engine cylinder liners
Andrzej Posmyk, Jerzy Myalski
Quarterly No. 1, 2017 pages 25-29
DOI:
keywords: alumina foam, glassy carbon, cylinder liner, friction, wear, composite
abstract The paper presents the influence of the reinforcing phase form on the structure and tribological properties of composites with an aluminum alloy (AlMg5) matrix containing glassy carbon as a solid lubricant. These composites are designed to produce cylinder liners of piston machines, namely air compressors, combustion engines and pneumatic actuator cylinders. The results of comparative examination of composites containing foam inserts made of Al2O3 coated with glassy carbon and composites containing foam inserts made from glassy carbon are presented. Adding Al2O3 foam to the AlMg5 alloy increases the compressive strength, but enhances the friction and wear of the sliding cast iron. The wear of the composite containing Al2O3 when rubbing against a pin made of cast iron GJL-250 is more than twice lower than the matrix. The presence of glassy carbon foam reduces the friction and wear of both the cast iron pin (more than five times) and the matrix. The presence of the Al2O3 foam in the AlMg5 alloy deteriorates the heat dissipation, causing an increase in temperature in the friction zone during friction in air against GJL-250 cast iron. The temperature in the friction zone of the composite with Al2O3 foam is more than 20°C higher than the friction zone of the composite comprising glassy carbon foam.