Powder removal is one of the most overlooked aspects of designing internal channels and cavities for metal additive manufacturing. Unlike traditional machining, powder bed fusion leaves unused powder trapped inside hollow features. Without careful design, this powder can remain stuck, adding weight, blocking flow paths, or compromising functionality.
Adding small draft angles, typically between 2° and 5°, creates a natural pathway for powder to flow out during depowdering. This subtle design change significantly improves cleanability without affecting part performance. It’s a simple example of how DfAM principles can prevent costly post-processing challenges.
Straight vertical walls or sharp corners often create dead zones where powder accumulates. Over time, trapped powder can sinter slightly during printing, making removal even more difficult. Draft angles reduce these risks by encouraging smooth material flow and minimizing powder buildup in blind cavities.
In production environments, small design decisions can have a large impact on repeatability and efficiency. Incorporating draft angles early in the design process helps ensure lighter parts, faster cleaning, and more reliable performance across multiple builds.