This lesson focuses on ACMONITAL—a specific type of stainless steel used in 20th-century Italian coinage, particularly the 50 Lire “Vulcano” coin. We shift from examining pure iron to understanding how iron is alloyed to create durable, corrosion-resistant materials. Through this case study, students explore alloy composition and analyze the coin using XRF spectroscopy.
Objectives
- Recognize Acmonital as an example of iron-based alloy
- Identify the primary elements in Acmonital and their function
Materials
- coin 50 Lire Vulcano 1977
Lesson Plan
- Discuss the typical composition of Acmonital:
- Iron (83–85%) – base element
- Chromium (12–13%) – corrosion resistance
- Nickel (2–3%) – hardness and silvery appearance
- Interpret the XRF results: identifying Fe, Cr, and Ni peaks
