Dry sliding wear mechanism for P/M austenitic stainless steels and their composites containing Al2O3 and Y2O3 particles

Austenitic stainless steels are used in applications demanding general corrosion resistance at room or moderate operating temperatures. However, their use is often limited by the relative softness of these materials and their suceptibility to wear and galling. The present investigation deals with the dry sliding wear behaviour of two P/M austenitic stainless steels (AISI 304L and 316L) and their composites containing two different ceramic particles (Al₂O₃ and Y₂O₃) and two different sintering activators (BN and B₂Cr). Unlubricated pin-on-disc wear tests were carried out. Wear mechanisms were analysed by means of scanning electron microscopy and X-ray diffraction. A plastic deformation and particle detachment wear mechanism was revealed. Plasticity during sliding induced an austenite to martensite transformation. The presence of ceramic particles (Al₂O₃ and Y₂O₃) and sintering activators (B₂Cr, BN) improved significantly the wear resistance (especially the combination Al₂O₃ and B₂Cr). Ceramic particles limited plastic deformation while sintering activators decreased final porosity.