How can you tell cast aluminum from aluminum?

 Differentiating between cast aluminum and regular aluminum can be done through various methods, including visual inspection, material properties, and manufacturing markings. Here are several ways to tell them apart:

1. Visual Inspection: Cast aluminum often has a rougher surface texture compared to regular aluminum. Cast aluminum parts typically show signs of the casting process, such as slight irregularities, surface imperfections, or visible parting lines. Regular aluminum, on the other hand, tends to have a smoother and more uniform appearance.

2. Density and Weight: Cast aluminum parts tend to be denser and heavier than their counterparts made from regular aluminum due to the casting process, which involves pouring molten metal into molds. You can compare the weight of the object in question to known samples of cast and regular aluminum.

3. Manufacturing Markings: Look for any markings or labels on the object that might indicate its manufacturing process. Cast aluminum parts may have markings such as "CAST," "CAST ALUMINUM," or specific manufacturer codes related to casting processes.

4. Surface Finish: Cast aluminum often retains the texture of the mold used in its production, resulting in a textured or slightly rough surface finish. Regular aluminum typically has a smoother finish, especially if it has undergone processes like machining or extrusion.

5. Microstructure Examination: Under a microscope, cast aluminum typically exhibits a dendritic or grainy microstructure, reflecting the solidification process from molten metal. Regular aluminum, depending on its processing history, may show a more uniform microstructure.

6. Sound Test: When tapped or struck, cast aluminum tends to produce a duller thud compared to the sharper ringing sound of regular aluminum due to its denser structure.

7. Chemical Composition Analysis: Advanced testing methods, such as chemical analysis or spectroscopy, can determine the exact composition of the material, including trace elements and alloying agents, which might differ between cast and regular aluminum.

These methods can help in distinguishing between cast 8020 aluminum and regular aluminum, but it's essential to use a combination of techniques for accurate identification, especially in cases where visual inspection alone may not provide conclusive results.