Journal des sciences et de l'ingénierie des matériaux

Heat Treatment Effect on Microstructural, Mechanical and Tribological Properties of Nickel Aluminium Bronze Alloy Manufactured by Laser Powder-Bed Fusion Technique

Abstract

Fathia Alkelae* and Shinya Sasaki

High density nickel-aluminium bronze alloy (Cu₉Al₄Fe₃Ni) was manufactured using Laser Powder-Bed Fusion Technique (L-PBF), it was investigated regarding the effect of different heat treatment conditions on its mechanical, microstructural and tribological behaviour. Correlations between the microstructures generated (k phases) and the behaviour observed were established. Regardless the heat treatment applied (annealing, tempering, quenching and tempering), friction coefficient, wear loss and hardness have been shown to decrease with increasing heat treatment temperature, while tensile strength and the elongation improved compared to the as-built sample. On the other hand, correlations using increased precipitates content resulting from different heat treatments confirmed the improvement of the material’s mechanical properties at the expense of the tribological ones. A possible interpretation of this results maybe the role of precipitates in impeding dislocations motion leading to increased shear forces, thus deteriorating the embeddability of the soft α phase along with detachment of the hard κ phases allowing a three body abrasive wear to occur. However, in a process similar to strain hardening, hardness and tensile strength are shown to improve with increased precipitation.