The forging process begins from the solid aluminum rod type 2618 or 4032. The 4032 is the material with higher silicon content with 12%. The addition of silicon greatly reduces aluminum’s expansion rate which quite similar to the casting piston. It also means that the piston can now run with tighter cold clearances. We usually suggest customers to use 4032 alloy with performance and even competition applications. However, its reduced ductility does make the alloy less resistant to cracking with extreme impact loads compare to 2618 alloy. The 2618 alloy, on the other hand, has very low silicon content. This makes a 2618 piston much more flexible, which offers advantages during high-load, high-stress applications and suitable for extreme motor sports like drag racing. However, this lower silicon content also means the piston has a greater thermal expansion rate which means the clearance during cold start will be greater compare to 4032. A 2618 piston will expand 15 percent more than a 4032 version. So during cold start the 2618 piston can be slightly noisier when cold as opposed to a comparable 4032 forging.

As for the forged production, we start from cutting the rod into smaller pieces after heated up to 150~200 degree Celsius. The punch is purposed to heat up to 426 degree Celsius and applies 500 to 1000 tons of hydraulic pressure onto the slug.

After the press process, the crucial step which is heat treatment will be performed. TIK Piston Taiwan is the only factory knows how to treat 2618 material with proper heat treatment. Without knowing how to do so, the stress cannot be released properly which will leads piston deform during engine operation and will kill the engine.

The last step is the similar process like traditional piston machining process. The main difference is that we use 4+1 axis CNC machine to decorate special areas of piston like piston crown, piston pin bore, piston side window and even piston chamfer. It brings the piston into art pieces.