Photomicrograph Gallery II:

Color Etching in Foundry Metallography . . .







Following are some examples of color etching in foundry metallography, working with aluminum silicon alloys.

Click a photomicrograph to open a larger, close up view.

Figure 1.  In an aluminum-silicon alloy, the precipitates of the silicon phase in the Al-7Si alloy are stained blue.

Figure 2.   When semi-solid forming aluminum-silicon alloys, alpha-phase primary dendrites were frozen, and were then deformed at the mold wall.

Figure 3.   In a study of Al-Si alloys, dendrites of rather regular shape were formed in the middle region of the casting.

Figure 4.   Weck's reagent helped to reveal the microstructure of the while layer in Ti-6-Al-4V cast in a ceramic mold. Figure 5.   Weck's reagent also revealed the alpha-beta microstructure of Ti-6Al-4V cast in a ceramic mold. Figure 6.   Microstructure of the white layer in Ti-6Al-4V cast in a graphite mold. The white layer was thinner than in the ceramic mold.