STUDIES OF AL2O3(P)-6061A1 COMPOSITES UNDER DRY SLIDING CONDITIONS USING SCANNING ELECTRON-MICROSCOPY, ENERGY-DISPERSIVE SPECTROMETRY AND X-RAY-DIFFRACTOMETRY

The debris and the worn surface after dry sliding wear were studied by scanning electron microscopy (SEM), energy-dispersive spectrometry (EDS) and X-ray diffractometry (XRD). A pin-on-disk method, in which the pin was the 15%Al2O3(p)-6061Al composites and the disk was a 52100 steel, was used. The microstructural features for severe wear appeared to be much coarser than those for mild wear. According to the EDS and XRD results, the chemical compositions of the debris for mild wear were different from those for severe wear. The debris for mild wear mainly consisted of ferric oxide (Fe2O3), while the debris for severe wear was composed Of Al2O3, Al and alpha-Fe. Cross-sectional SEM images showed that Al2O3 particles near the composite surface did not suffer obvious deformation. Thus, it seemed to be the Al2O3 particles which make the composite more wear resistant under the mild wear conditions. However, in the severe wear conditions, many Al2O3 particles near the surface were broken off, which prevented them from resisting wear.