Final answer:
Alloying is the process of combining metals to create an alloy with desired properties. In this case, alloying, usually with rhenium, increases the mechanical strength of the alloy to withstand high-speed rotation and thermal expansion and contraction. Superalloys, like stainless steel, are commonly used for such applications.
Step-by-step explanation:
Alloying is the process of combining two or more metals to create an alloy with desired properties. In this case, alloying, usually with rhenium, is used to give the alloy added mechanical strength. This is important in applications that involve high-speed rotation and repetitive thermal expansion and contraction.
Superalloys are a type of high-strength alloy that are commonly used in such applications. They are usually based on cobalt, nickel, and iron, and have complex compositions. Superalloys exhibit excellent mechanical strength, high surface stability, and resistance to high temperatures.
For example, alloying iron with other metals, such as chromium, can create stainless steel. The added chromium forms a protective oxide layer on the surface of the alloy, which helps protect the iron from corrosion.