Influence Of Fe On Microstructures And Wear Behaviors Of A High-aluminum Bronze

A new kind of Cu-14Al-X high-Al bronze was developed by the researchers in our laboratory, which can be used as die material and applied in drawing and extruding stainless steel of plate heat exchanger. Fe element plays an important role in wear behaviors and mechanical properties of the aluminum bronze. Major researches were focusing on aluminum bronzes which have a ferrous content from 2 % to 4 %, and few were done on aluminum bronzes which have a ferrous content of over 4 %. This article probes into influences of Fe on as-cast and past heat treatment microstructures, and wear behaviors of the high-Al bronze.As-cast and past heat treatment microstructures of the high-Al bronze with different mass fraction of Fe element were observed and analyzed by MEF3, XRD and EPMA. Results indicated that, to the different contents of Fe element of as-cast alloys, microstructure of all the alloys consist ofγ₂,β',K and a phases, heat treatment only changes the phase contents. With increase of Fe content, the grain of the high-Al bronze refined and precipitation surface topography of k phases and distribution of the eutectoid phases have been also changed, the content of the eutectoid phase raised too. Through solution treatment, content of K and a phases reduced, content of (3' phase increased. Past aging heat-treatment, the size of k phases reduced and the distribution of K phases and eutectoid phases present a diffusive trend. The alloy with a 4 % Fe content has more homogeneous microstructure and higher hardness.Dry wear behaviors of this high-Al bronze with different mass fraction of Fe were examined in pin-on-bar reciprocating device. Surface topographies of grinding crack and the grindings on/in the alloys were observed by SEM, results shown that the alloy performs an abrasive wear behavior. The bronze with 4 % ferrous content has higher wear resistance and lower friction coefficient.