TUHH Open Research
 

Towards controlled processing of high-conductivity Cu alloy (CuCrZr) on Inconel (IN718) substrate through beam shaping and process control in PBF-LB/M

Journal
Journal of materials processing technology  
Volume
354
Article Number
119395
Citation
Journal of Materials Processing Technology 354: 119395 (2026)
Publisher DOI
10.1016/j.jmatprotec.2026.119395
Scopus ID
2-s2.0-105042784832
Publisher
Elsevier
Multi-material components that combine high-temperature structural performance with high thermal conductivity are of growing interest for advanced engineering applications. Laser powder bed fusion of metals (PBF-LB/M) offers unique opportunities to fabricate such components with precise control over geometry and composition, but the early stages of multi-material deposition remain poorly understood. In particular, the influence of substrate properties and process variables on interface formation, intermixing control, and defect evolution has not been systematically studied, especially for challenging alloys like copper and nickel-based superalloys. In this work, single-track experiments are conducted to investigate the deposition of a CuCrZr alloy on an IN-718 substrate, targeting the reduction of interfacial intermixing while preserving bonding integrity. The effects of laser power, scan speed, and laser beam shaping on melt pool morphology, substrate remelting, and compositional control at the interface are evaluated. Ring-dominant beam profiles achieve higher Cu retention (up to 53.9 wt% for Mode 3 and 47.5 wt% for Mode 6, versus 39.7 wt% for Gaussian), suppress keyhole formation, and substantially reduce the heat-affected zone width from 45 to 115 µm for Gaussian sources down to below 20 µm for Mode 6, which additionally decouples HAZ extent from process parameters. Liquation cracking at the HAZ, associated with Laves phase along Nb-enriched grain boundaries, was observed exclusively under core-dominant, high energy density conditions. Single-track experiments were deliberately selected as they represent the earliest and most substrate-dominated deposition stage, where thermal gradients are steepest and substrate-driven cracking mechanisms are most directly isolated. These results establish a mechanistic framework for understanding early-stage multi-material deposition, informing process parameter design in more complex geometries and guiding future studies aimed at controlling interfacial intermixing, minimizing defects, and improving the reliability of multi-material additive manufacturing.
Subjects
Beam Shaping
Cracking
Multi-material
PBF-LB/M
DDC Class
540: Chemistry