DOI: 10.3390/ma19194169 ISSN: 1996-1944

Multi-Factor Prediction of Cumulative Deposited Height in CMT Wire Arc Additive Manufacturing Using an Improved Temporal Convolutional Network

Yuwen Wang, Qikuan Zhao, Haocheng Wu, Longjian Zhou, Hao Deng, Yu Fan, Xue Li, Jie Xu, Zheng Chen, Lin Wang

Cold Metal Transfer wire arc additive manufacturing (CMT-WAAM) efficiently fabricates medium and large metallic components, yet deposited wall cumulative height varies spatially along the build direction and deposition path due to heat accumulation, inter-layer cooling, travel direction and inherited layer geometry. This study establishes a multi-factor prediction framework for single-bead multi-layer walls and evaluates CAFi-TCN, a temporal convolutional network enhanced with feature-wise linear modulation and causal attention. Height profiles were extracted from registered point clouds under 2–4 mininter-layerr cooling; the model uses deposition position, layer number, cooling time, travel direction, prior height increment and cumulative height to predict current-layer cumulative height. On the tenth-layer test set, CAFi-TCN achieved the lowest mean absolute error (MAE = 0.1836 mm) among the evaluated direct-height models, reducing MAE by 74.3%, 40.4% and 53.9% versus standard TCN, polynomial ridge regression and MLP, respectively. A Random Forest model trained on the height-increment target (RF-Δ) produced slightly higher MAE but lower RMSE and maximum absolute error, showing a trade-off between average-error control and extreme-error suppression. Additional no-PreDH, simple increment-baseline, path-block bootstrap and rolling-layer analyses show that prediction performance depends on both process-state variables and inherited geometry rather than simple copying of the previous layer. The results support bounded, layer-wise height forecasting for single-bead WAAM walls and provide a basis for pre-adjustment error identification.