What is one disadvantage of powder metallurgy methods?

The correct choice highlights a notable disadvantage of powder metallurgy methods, which is the potential for variations in density in the components produced. In this manufacturing process, metallic powders are compacted and then sintered to create solid parts. However, the distribution of the powder can lead to inconsistent densities within the finished components. Variations in density can affect the mechanical properties of the final product, leading to performance issues in applications where uniformity is critical.

In contrast, the other options present benefits rather than disadvantages. Low tooling costs and low expense of metal powders suggest economic advantages, making the powder metallurgy process accessible for various applications. Additionally, the ease of storing metal powders implies an operational benefit that allows for flexibility in production scheduling and material handling. Understanding this distinction helps to appreciate the specific challenges associated with powder metallurgy, particularly in achieving consistent quality across production batches.