Which expands faster, cast aluminum or cast iron alloy?

Cast aluminum expands faster than cast iron alloy due to its lower density and different material properties. When materials are subjected to temperature changes, their molecules gain kinetic energy, causing them to vibrate more and occupy a larger volume, resulting in thermal expansion.

Aluminum, being a lightweight metal with a higher coefficient of thermal expansion compared to iron, will experience more significant dimensional changes as temperature increases. This property is crucial for applications involving heat management and structural integrity in engines and other mechanical systems where thermal fluctuations occur frequently.

On the other hand, cast iron has a higher density and lower thermal expansion rate, making it more stable in terms of dimensional changes under heat exposure. This characteristic of cast iron is beneficial in applications where strength and durability are prioritized over weight.

Understanding these properties is critical in engineering design, especially when choosing materials for components that will undergo varying temperature conditions, ensuring compatibility and performance over the product's lifecycle.