A synergistic impact of LPBF process parameters on attaining a defect-free Cu-Cr-Zr alloy parts: an analytical and experimental study

The Cu-Cr-Zr alloy has an important role in the domain of thermonuclear fusion and electronic applications. But due to their higher thermal conductivity and reflectivity, the laser powder bed fusion (LPBF) manufacturer faces many defect formations such as balling effects, spattering effects, and un-melted powders during the fabrication of Cu-Cr-Zr alloy. However, these defect formations can be reduced by analyzing and evaluating the interactions of parameters. In this research, a correlation of LPBF process parameters such as laser power (250, 350, and 450 W), scan speed (750, 850, and 950 mm/s), and hatching distance (0.05, 0.07, and 0.09 mm) was investigated to achieve defect-free Cu-Cr-Zr parts with reduced porosity and surface roughness with maximum nanohardness. The combined analytical approach based on integrated entropy and Deng’s similarity validated the experimental study. Major defects such as cavity formation, lack of fusion between the layers, and improper melting of Cu-Cr-Zr powder particles were evident during the reduced energy density of around 100 to 200 J/mm³ during the adoption of a minimum laser power of around 250 to 300 W. The outcome shows that defect-free parts with reduced porosity of 0.88%, reduced surface roughness of 23.24 µm, and maximum nanohardness of 5.2 GPa were achieved during the optimal setting of 450 W laser power, 850 mm/s scan speed, and 0.05 mm hatching distance. LPBF Cu-Cr-Zr alloy with optimal combination offers 278.92 MPa in ultimate tensile strength and 11.69% in ductility. The optimal settings obtained from the experimental study are in greater agreement with the integrated entropy and Deng’s similarity approach.