As is well-known, the piston for the internal combustion engine has a number of rigid and yet
diverse requirements. That is, the piston is should be light in weight and yet also high in
strength.
By adding silicon, the ability to cast the piston can be improved since the melting point is
lowered and the flow of molten material is facilitated. Also, the silicon resists deformation at
high temperature by lowering the coefficient of thermal expansion. In addition, resistance
against wear and fatigue under high speed sliding action is improved.
However, silicon has a considerably lower thermal conductivity than aluminum. Thus, aluminum
alloys having large amounts of silicon have low thermal conductivity. Therefore, heat
dissipation is deteriorated and thus, overheating particularly in the head area results.
Turn these blocks of aluminium "called the billets" into pistons.
The lubricant is graphite-based lube.
The billet is first heated to 460 degrees C to make the alloy malleable enough to be forged.
Paint the graphite-based lube on the billet which stops everything from sticking onto the tool.
The hydraulic forge press has squeezed up with the equivalent on the preheat aluminium billet,
creating the basic shape of the piston. Compare to Alcoa forged the wheel of Lamborghini. Basically, it is the same principle.
Quick visual check everything is OK!!
The pistons are dropped into the secret solution, as they cool would increase strength.
Acid to remove the graphite lubricant. Place in the acid for four minutes and washed off.
The left is after acid. This right is not.
Push into the oven.
CNC Machine to post-process.
Note that the video jumped over several steps of pistons manufacturing.
Piston Ring: Compression Ring and Oil Ring Wrist Pin Hole
The cylinder is the engine liner.
Reference :
1. How to Build a Super Car. BBC
2. Aluminum Alloy for Piston and Method for Producing Method. US Patent
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