Alloys

Name the two types of alloys illustrated above.

How is an alloy different from a pure metal?

Consider the two types of alloys. Based on the diagrams, define “substitutional” and “interstitial” in your own words.

One of the alloys in Model 1 tends to form when elements with similar sized atoms are melted

together and allowed to cool. The other type forms when elements with very different sized atoms

are combined. Match the descriptions below with each type of alloy.

Explain why an interstitial alloy would not form a stable crystal structure if the component

atoms were of similar size.

Sketch a diagram to illustrate your answer for question 5.

Explain why a substitutional alloy would not form a stable crystal structure if the component

atoms were different sizes.

Sketch a diagram to illustrate your answer for question 7.

Would substitutional alloys tend to have a density similar to, significantly greater than or

significantly less than the pure metal?

Would interstitial alloys tend to have a density similar to, significantly greater than or

significantly less than the pure metal?

Metals are malleable because of weak bonds between atoms. This allows planes of atoms to slide

past one another and into new positions. Some alloys retain their malleability while others become

more rigid. Consider the diagrams above. Predict which type of alloy would result in a more

rigid substance. Justify your reasoning.