Metal Additive Manufacturing Conference - MAMC 2023

Metal additive manufacturing (AM) is an essential technology in digital manufacturing and has been applied in various fields. Laser beam powder bed fusion (PBF-LB) is the most widely adopted AM technique. However, since the PBF-LB process inevitably generates internal defects in its built material, developing a real-time monitoring and feedback control technology is highly demanded for quality assurance of PBF-LB products and process reproducibility. Therefore, we investigated the correlation between surface texture parameters, built material density, and internal defects to investigate the possibility of using surface texture parameters as feedback input.
An in-situ monitoring method capable of simultaneously measuring the surface textures of the powder bed and the manufactured product was developed. It can measure the surface characteristics layer-by-layer using the fringe pattern projection method and calculate 15 surface texture parameters defined by ISO standards. Samples were prepared by varying the scanning speed and laser power, and the surface properties of each layer were measured. The relative density of the samples was measured. The spatial distribution of internal irregularities was also measured by X-CT imaging.
The results showed a strong correlation between surface texture parameters, density, and internal defects. It suggests that in-situ monitoring of specific areal surface texture parameters can be used as input variables for feedback systems to predict and prevent defect generation during the PBF-LB process.