Microstructural and Tribological Characterization of Aluminium Bronzes with Additions of Si and Cr.

The article presents the investigation results of the crystallization (performed by means of the TDA method) and the microstructure of complex aluminium bronzes with the content of 6% Al, 4% Fe and 4% Ni, as well as Si additions in the scope of 1-2% and Cr additions in the scope of 0.1-0.3%, which have not been simultaneously applied before. For the examined bronze, the following tests were performed: hardness HB, impact strength (KU₂). For bronze CuAl6Fe4Ni4Si2Cr0.3, characterizing in the highest hardness, wear tests were conducted with dry friction and the dry friction coefficient. The investigations carried out by means of the X-ray phase analysis demonstrated the following phases in the microstructure of this bronze: αCu, γ² and complex intermetallic phases based on iron silicide type Fe₃Si (M₃Si M={Fe,Cr,...}). Compared to the normalized aluminium bronzes (µ=0.18-0.23), the examined bronze characterizes in relatively low wear and lower friction coefficient during dry friction (µ=0.147±0.016). [ABSTRACT FROM AUTHOR]