Abrasive wear resistance of ruthenium aluminide intermetallic and ferritic steels containing a sigma intermetallic phase

Abstract

The abrasive wear resistance of ruthenium aluminide intermetallic and ferritic steel containing an iron-chrome sigma intermetallic phase have been investigated in this study. A medium carbon wear resistant steel (MCV) was used in the study to facilitate comparison between wear resistances in the materials of interest. Specimens of ruthenium aluminide, MCV and ferritic stainless steels containing a sigma phase were produced. The MCV steel was quenched and tempered to match the bulk hardness of the as-received ruthenium aluminide. Five different grades of thermomechanically worked ferritic steels specimens were heat treated to produce different volume fractions of sigma phase. The mechanical properties of the specimens were investigated by compression testing and microhardness measurements. Abrasion testing was carried out on a pin on belt abrasion apparatus. The surface response of the specimens to abrasive wear was characterised by optical and scanning electron microscopy. Microhardness of the specimens were measured with a digital microhardness machine. The wear resistance of ruthenium aluminide was found to be higher than all materials tested in this project. The wear resistance in some of the ferritic steels containing sigma phase was comparable to that of the wear resistant medium carbon steel. The surfaces of the specimens were shown to work-harden during the abrasion process. The corresponding work-hardening results showed that ruthenium aluminide had the highest work-hardening rate. It can be concluded that the work-hardening ability of the test materials correlates with their respective wear resistance properties.