Which of the following is a disadvantage associated with directed energy deposition?

The selection of the disadvantage that newly deposited material may vary in microstructure from the base material highlights a critical consideration in directed energy deposition (DED). This process involves melting and fusing materials to create new structures on top of existing ones, which can lead to different thermal cycles and cooling rates compared to the parent material. As a result, the microstructural characteristics, such as grain size, phase distribution, and mechanical properties, might differ significantly from those of the base material. This variation can affect the performance and integrity of the final product, especially in applications requiring high material consistency and reliability, like aerospace and medical components.

Understanding the microstructural implications is essential for engineers and manufacturers utilizing directed energy deposition technology, as it can influence decisions in material selection, process parameters, and post-processing treatments needed to achieve desired mechanical properties. The other options, while they may contain valid points regarding DED, do not capture this significant aspect of microstructure variability that directly impacts the quality and performance of the deposited materials.