Friction and wear behavior of sintered magnesium composite reinforced with CNT-Mg2Si/MgO

In order to improve and evaluate the wear behavior of the sintered magnesium materials under dry sliding conditions, the effect of carbon nanotubes (CNTs) and Mg2Si/MgO compounds, which were reinforcements of the sintered material, on the friction coefficient and wear loss under dry conditions was discussed. One of the raw materials was amorphous and porous silica particles originated from rice husks, which were coated with CNTs and contained nanotubes in the pores. The in situ synthesis of Mg2Si and MgO via deoxidization and oxidation reaction occurred from the elemental mixture of pure magnesium and CNT-SiO2 composite particles via the spark plasma sintering process. The friction coefficient of the composite material was low and stable because of no adhesion and stick-slip phenomenon in contacting with the SUS304 stainless steel ball as a counter material. The wear rate of sintered magnesium materials decreases in increasing the content of CNTs and Mg2Si. The friction coefficient was proportional to the total wear loss of magnesium materials. These results were due to both of the defensive by hard Mg2Si dispersoids and self-lubricant effect by network nanotubes on the sliding surface.