Wear of Al-Mg-Cu composite reinforced by in situ formation of ceramics

An Al-Mg-Cu composite reinforced by ceramic phases MgAl2O4, MgO and Mg2Si was fabricated by a powder metallurgy process, in which about 20 wt.% of SiO2 content was added into Al-Mg-Cu matrix and then the reaction between them took place during a sintering process. The X-ray analysis proves that ceramic phases MgAl2O4, MgO and Mg2Si are formed in primary SiO2 grains of the composite. The sliding friction wear properties of the composite are studied, which shows that the maximum load for the composite is less than 196 N under dry wear condition, and that under lubricated wear condition the maximum volume loss is not more than 0.8 mm3 at a load of 1764 N, and the friction factor is less than 0.14. Further study on the inferior layer of wear surface for the composite shows that under dry wear condition the inferior layer appeared plastic deformation, SiO2 particles are broken, and which are synchronously moved along the direction of the plastic deformation; under lubricated sliding wear condition the above case is no appearance. The results show that the composite is applicable to lubricated sliding friction wear under heavy loads (≤1764 N).