Predicting cracks during laser-directed energy deposition of ceramics

In laser-directed energy deposition (LDED), an additive manufacturing process, a laser melts and deposits a material layer by layer. This efficient and cost-effective process could fabricate ceramic components for defense, aerospace, and biomedical applications. However, LDED often leads to performance-degrading cracks in brittle ceramics.

Researchers lack practical methods to predict and prevent the formation of these cracks. Li et al. developed an approach that combines thermal feature analysis and machine learning to accurately predict crack formation during LDED of ceramics. This method eliminates the need for measuring internal residual stress, a key contributor to crack formation that is challenging to measure directly and in real time.

The rapid heating and cooling in LDED drive the buildup of residual stress. Traditional methods, which try to predict crack formation using fixed-point temperature sampling, fail to take into account the dynamic behavior of the melt pool, where the material is molten. In contrast, the authors introduced a strategy that extracts stable, frequency-domain thermal features directly from dynamic contour points, which outline the evolving melt pool.

They found that this framework enables a more robust and mechanistic correlation between melt-pool thermal dynamics and resultant crack formation, improving the accuracy and interpretability of crack-rate prediction.

“This work establishes a data-driven and physically interpretable framework for predicting crack-rate in ceramic additive manufacturing,” said author Haiying Wei. “The proposed method enhances the reliability and accuracy of defect prediction and supports the future development of process monitoring and control strategies in laser-directed energy deposition.”

Next, the authors will extend this approach to monitor other features of a material during LDED.

Source: “Physically interpretable crack prediction using dynamic contour point-based frequency-domain gray-level features in laser-directed energy deposition of alumina ceramics,” by Bin Li, Haiying Wei, Yi Zhang, Yuchao Lei, Xuni Yin, and Shiyu Cao, Journal of Laser Applications (2025). The article can be accessed at https://doi.org/10.2351/7.0001969 .