Core-shell structure in situ reinforced aluminum matrix composites: Microstructure, mechanical and tribological properties

Aluminum matrix composites with in situ core-shell structure were successfully prepared by powder metallurgy. And the microstructure, mechanical properties and tribological behavior of core-shell structure reinforced aluminum matrix composites were investigated in detail. The results indicate that double core-shells of Al3Ni and NiAl are formed between the Al matrix and Ni3Al reinforcements. The combined effect of Ni3Al reinforcements and the in situ core-shell structure enhance the mechanical and tribological properties of the composites, which is due to the improved strength of the composites and bonding strength between the reinforcements and matrix. Moreover, the serious adhesive wear is significantly alleviated for the composites. Overall, the N15 composite reinforced with 15 vol% Ni3Al exhibits good comprehensive properties, which shows the highest compressive strength of 248 MPa with a strain of 10%, and the optimal friction coefficient and wear rate of 0.74 and 6.45 × 10−5 mm3/(N m), respectively.