Compensation for Uneven Surfaces When Building Laser Deposited Structures 471
MetadataShow full item record
Direct Laser Deposition (DLD) is a blown-powder laser deposition process that can be used to quickly produce, modify or repair fully-dense metallic parts by a layered manufacturing method. However, uneven substrate surfaces often cause variation in the deposited layer which is magnified by succeeding layers. Research carried out at the University of Liverpool has resulted in a non-feedback layer height controlling process based on controlling the shape of the powder streams emitted from a four-port side feed nozzle. This method limits deposited layer height by causing a sharp reduction of catchment efficiency in the vertical plane at a fixed distance from the powder feed nozzle, and is therefore capable of depositing a consistent layer height in spite of power, powder flow or process velocity variation. This paper demonstrates how this method of layer height control can compensate for irregular substrate surfaces in the production of accurate DLD parts.