Study On Tribological Properties Of TiAl Matrix Self-lubricating Composites

Currently, solid self-lubricating composites over a wide range of temperature are significantly needed to be researched. Most common lubricants only perform within a narrow temperature range, such as C, MoS2, BaF2and Ag. Thus, the combination of two or more than two lubricants is one of the effective methods to realize lubrication over a wide temperature.The paper designs TiAl matrix self-lubricating composites applied in a wide temperature range from lubrication phase and lubricant addition amount. We prepared TiAl matrix self-lubricating composites containing Ag, Ti3SiC2and Ag+Ti3SiC2using spark plasma sintering. The structural characteristics, physical properties of TiAl matrix self-lubricating composites containing different lubricants were studied; the tribological properties of TiAl matrix self-lubricating composites containing different lubricants from25to800℃were studied; the synergetic effect of composite lubricants of Ag and Ti3SiC2were studied; the microstructures and composition were analyzed by X-ray diffraction (XRD); the worn surfaces, cross-section of wear scar, wear debris, wear mechanisms and lubrication mechanisms were analyzed by scanning electron microscopy (SEM), field emission scanning electron microscopy (FESEM), X-ray photoelectron spectroscope (XPS), electron probe microanalyzer (EPMA) and energy dispersive spectroscopy (EDS).The tribological behavior of TiAl matrix self-lubricating composites (TMSC) containing Owt.%,5wt.%,10wt.%and15wt.%Ag investigated from25to800℃at the condition of10N-0.234m/s indicated that:Ag could improve the tribological properties of TMSC at25-400℃; TMSC containing10wt.%Ag exhibited the best tribological properties over the wide temperature range.The tribological behavior of TiAl matrix self-lubricating composites (TMSC) containing Owt.%,5wt.%,10wt.%,15wt.%and20wt.%Ti3SiC2investigated from25to800℃at the condition of10N-0.234m/s indicated that:Ti3SiC2could improve the tribological properties of TMSC at above400℃; TMSC containing15wt.%Ti3SiC2exhibited the best tribological properties over the wide temperature range.The tribological behavior of TiAl matrix self-lubricating composites (TMSC) containing Owt.%Ag+Owt.%Ti3SiC2and10wt.%Ag+15wt.%Ti3SiC2investigated from25to800℃at the condition of10N-0.234m/s indicated that:at all temperatures, the friction coefficients and wear rates of TMSC containing Ag and Ti3SiC2were lower than those of TiAl alloy; the Ag and Ti3SiC2exhibited the best synergetic lubrication effect over the wide temperature range; adding Ag and Ti3SiC2into TMSC was an effective way to widen operating temperature range of high-temperature self-lubricating materials.