Effect of Si content in hot dipping aluminium bath on Al–Fe bonding layer of aluminium piston with reinforced cast iron ring

Pistons with reinforced cast iron ring are produced to meet the increasing performance requirement of internal combustion engines with high power. The intermetallic bonding between piston alloys and cast iron ring must be able to withstand the high pressure and high temperature environment of internal combustion engines. Consequently, the quality and strength of the intermetallic bonding are very important in piston manufacturing. In the present work, the effects of Si content variation in the hot dipping aluminium bath on interface reaction and the intermetallic bonding strength between the cast iron ring and the piston alloys are investigated. The results indicate that bonding strength increases with the increase in Si in the hot dipping aluminium bath to eutectic composition and decreases with excess Si. The mechanism for the variation of bonding strength is also discussed.