AISiGr-A Dream Alloy for IC Engine Cylinders?

Cylinder liners made of AlSi alloy graphite composite using UPAL process have worked satisfactorily in a two-stroke petrol engine. Results of standard engine tests and field trials indicate that, compared to standard cast iron liners. AISiGr liners lead to (a) considerable improvement in the power output as a result of reduced frictional losses, (b) appreciable reduction in the specific fuel consumption and wear of the tribo components and (c) marked improvements in the resistance to seizure of the piston-liner assembly. It was also observed that the problem of cold start which is inherent in uncoated AlSi alloy liners did not exist with AISiGr liners. However, this observation could not be quantified in the present investigation.

SEM and ESCA studies on the tribological surface of the liners were carried out and the results also support the above findings.