Microstructure, Mechanical and Tribological Properties of (CuMnNi)_100-xAl_x High Entropy Bronzes

In view of the demand for new metallic materials with high strength and good wear resistance in the industrial field, a series of (CuMnNi)_100-xAl_x (x = 0, 5, 10, 15) high entropy bronzes were prepared. The phase constitution, microstructure, mechanical and tribological properties of the high entropy bronzes were investigated systematically. The results indicated that the CuMnNi high entropy alloy was composed of a solid solution phase with a face-centered cubic structure (FCC). The addition of Al produced a high solid solution strengthening effect on the FCC phase of the alloy and promoted the formation of the body-centered cubic (BCC) phase. The FCC phase had good plasticity and toughness, while the BCC phase had high strength and hardness. The combined effect of the FCC+BCC phases increased the strength of the (CuMnNi)_100-xAl_x high entropy bronzes by increasing of Al content, while the plasticity and the toughness decreased. The content ratio of the FCC phase and the BCC phase in the (CuMnNi)₉₀Al₁₀ high entropy bronze reached the best combination, i.e. the alloy had excellent comprehensive mechanical properties. At room temperature, due to the good mechanical properties and good abrasion resistance of the hard BCC phase, (CuMnNi)₉₀Al₁₀ high entropy bronze showed better wear resistance than conventional wear-resistant aluminum bronze C6161, and abrasive wear was the main wear mechanism.