Why the standard approaches to AM finishing fall short
AM components carry three properties that make conventional finishing unsuitable: extreme geometric complexity, delicate surface tolerances, and the presence of un-sintered or partially sintered powder. Each of these demands a process with genuine finesse.
vs. dry blasting: Dry blasting delivers force without control. The absence of water means no cushioning effect, no lubrication between media and surface, and a genuine risk of media embedment in the component. On titanium, it carries an additional hazard: titanium dust from dry blasting is combustible, and the static charge generated can cause ignition. For DMLS titanium components, that is not an acceptable risk. Dry blasting also cannot reliably clear internal channels. It is possible to compact loose powder further into a channel rather than remove it, creating a blockage with no visible indication of the problem.
vs. chemical etching and electrochemical polishing: These processes can achieve low Ra values on external surfaces. They cannot selectively treat specific surface regions, they require hazardous chemistry and the associated handling, storage, and disposal costs, and they provide no compressive stress benefit. For parts with complex internal geometry, uniformity of treatment is difficult to verify and difficult to achieve.
vs. mass finishing (vibratory/tumble): Effective for simple external geometries and batch processing of small polymer parts. The media flow cannot reliably reach and treat complex internal channels. It provides no peening benefit. And for high-value, low-volume metal components, batch processing introduces the risk of part-on-part contact damage.
Find out how wet blasting compares with other finishing processes
