Process Optimization and Performance Evaluation of CuCrZr Alloy Deposited by Blue–Near-Infrared Hybrid Laser Directed Energy Deposition

The high thermal conductivity and low initial near-infrared laser absorptivity of T2 pure copper hinder stable deposition of compositionally similar CuCrZr alloys. This study deposited CuCrZr on T2 copper using hybrid blue and near-infrared laser directed energy deposition, targeting 15% dilution. Single-factor experiments established the process window; Taguchi orthogonal experiments, signal-to-noise ratio analysis, and analysis of variance identified optimized parameters. Independent replicates and microstructural and performance characterization verified the optimization. FLOW-3D simulations supported analysis of deposit formation and interfacial fusion. Scanning speed and hatching distance were the main factors affecting dilution within the investigated window. The optimized near-infrared laser power, powder feed rate, scanning speed, and hatching distance were 2700 W, 12 g/min, 18 mm/s, and 0.7 mm, respectively. Validation experiments yielded 14.81% mean dilution, with complete deposit cross-sections and continuous interfaces. CT measurements indicated approximately 99.99% relative density in specimens deposited using these parameters. Compared with the substrate, mean microhardness increased by 15.90%, mean friction coefficient decreased by 20.5%, and wear volume and specific wear rate both decreased by 49.9%. This study provides a process basis for stable CuCrZr deposition and surface strengthening on pure copper.