Recognizing of Performed Process

[MetalEng]

How can one recognize existing condition between following conditions:
* as-cast aluminum billet
* as-extruded aluminum billet
* as-forged aluminum billet
Please describe about apparent signs.

 

[trytrue]

I do not remember very well the surface of as-forged aluminum billet but these are my observations about these billets. I hope it help.
As-cast aluminum billet, it can be continuous casting or batch mold casting. The surface of the continuous casting has parallel lines like wrinkles and of course rough surface; these wrinkle lines are perpendicular to the exit direction of the billet. Batch mold billet has a smoother surface, it has the replica of the mold paint.

As-extruded aluminum billet has parallel lines some times very fine and others not. These lines are parallel to the exit direction of the billet.

As-forged aluminum billet has the surface really smooth no mold paint marks, no lines or wrinkle lines.

However, if they are machined the only way to determine the process is by metallographic analysis. The microstructure is quite different for the same alloy made by these three different processes.

 

[arunmrao]

Visual identification of the ingots may need a very experienced eye.. However, macro etching of the samples can reveal the differences.