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Abstract The potential tribological properties of load-adaptive M50-based self-lubricating composites under various loads were investigated. Pure M50 and M50 composite containing 10 wt%(50Sn40Ag10Cu) (MSAC) samples were prepared by spark plasma sintering. Besides, samples M50 and MSAC, which were all surface-scattered with C60 microparticles, were defined as M-C and MSAC-C, respectively, and the tribological tests of M50, MSAC, M-C, and MSAC-C sliding against Si 3 N 4 ball from 2 to 18N at 0.2 m/s-350 °C were performed. Results show that MSAC-C exhibits the excellent friction and wear performance within the range of loads. Analysis indicates that this phenomenon is mainly due to the formation of a composite lubricating film rich in soft metal lubricant Sn-Ag-Cu and C60 microparticles. Graphical abstract Image 1 Highlights • Sn-Ag-Cu provides excellent lubricating properties within the low loads from 2 to 12N. • C60 provides excellent lubricating properties within the high loads from 12 to 18N. • (Sn-Ag-Cu)-C60 has the merit of load-adaptive action to produce good lubrication. • Compounds of Fe 2 O 3 , CuO produced friction process can enhance lubrication capacities. [ABSTRACT FROM AUTHOR]

To overcome the poor tribological performance of titanium alloys and broaden their applications in the rapidly developing aerospace industry, this paper studies the friction and wear behaviors of TC4 alloy with surface microporous channels filled by Sn-Ag-Cu (SAC) and Al 2 O 3 nanoparticles using the dry sliding tests. Moreover, the synergistic lubricating mechanism of SAC4 and Al 2 O 3 nanoparticles is also investigated in detail. The results show that TC4 alloy with surface microporous channels filled by SAC4 (50Sn-45Ag-5Cu) and 6 wt% Al 2 O 3 nanoparticles (TC4-SACA3) presents excellent antifriction property and wear resistance over a wide range of temperatures and applied loads. Especially at 400 °C-10 N, TC4-SACA3 can obtain the smallest friction coefficients of 0.185 and the minimal wear rate of 3.6 × 10−5 mm3N−1 m−1, which is attributed to the synergistic effect of SAC4 and Al 2 O 3 nanoparticles. During the sliding process, SAC4 can precipitate from the microporous channels under the heat-force driving and then gradually form a smooth lubricating film on the friction surface. Meanwhile, some Al 2 O 3 nanoparticles wrapped by lubricant SAC4 can improve the load carrying capacity of lubricating film, and the other exposed Al 2 O 3 nanoparticles on the friction surface play a role of "micro-bearings" between the friction pairs. Unlabelled Image • TC4 alloy with surface microporous channels is prepared by LAM technology. • SAC4 has good wettability with TC4, preventing lubricating film peeling prematurely. • Pores with SAC and Al 2 O 3 nanoparticles present anti-friction and anti-wear abilities. • TC4-SACA3 maintains excellent self-lubricating property in tough friction condition. [ABSTRACT FROM AUTHOR]

M50 steel is the main material used in aircraft bearings, and its friction performance will directly affect the reliability and service life of the whole bearing. Hence, this paper focuses on the tribological behavior and self-healing function of as-prepared M50 steel-based self-lubricating material covered with surface micropores filled with Sn-Ag-Cu (MMSAC). Friction results show that MMSAC exhibits the distinguished tribological behavior. Analysis indicates that this is mainly due to the lubricating film formed on the worn surface and the self-healing behavior on the worn surface of MMSAC. Sn-Ag-Cu in micropores can precipitate onto the friction surface to form the lubricating film, while the volume expansion caused by the oxidation of Sn and Cu plays an important role in filling cracks. [ABSTRACT FROM AUTHOR]

Taking GCr15 steel as the research object, the groove-textured surfaces (GTSs) and the composite antifriction surfaces (CASs) with the grooves and Sn–Ag–Cu were prepared. Experimental researches on the tribological performance, friction-induced vibration and noise of SS (smooth surface), GTSs and CASs were conducted. The results showed that SS exhibited the obviously abrasive wear characteristics, thus the uneven surface was obtained, leading to the high-frequency scream. The fluctuation of friction force caused by the grooves on GTSs could suppress the high-frequency scream but cause the low-frequency chatter. The cooperate effect of grooves and Sn–Ag–Cu increased the fluctuation amplitude of friction force, hence CASs profile with obvious wrinkles was formed, suppressing the friction-induced vibration and noise. Image 1 • The noise is suppressed by the cooperate effect of grooves and Sn–Ag–Cu. • The grooves could suppress the scream and cause the low-frequency chatter. • The amplitude of frictional force fluctuation is increased by Sn–Ag–Cu. • CASs profile with obvious wrinkles could suppress the vibration and noise. [ABSTRACT FROM AUTHOR]

Tribological and frictional noise properties of TC4 with different sizes of surface dimples filled with Sn–Ag–Cu (SAC) and TiC are investigated using friction and noise experimental apparatus. The results show that TC4 with surface dimples of 0.6 mm diameter (TSC-0.6) has the best tribological property and frictional noise suppression capability. It is attributed to the synergistic effect of SAC and TiC, which can be easily extruded to the worn surface to form a complete lubricating layer. Meanwhile, the roughness of the worn surface is decreased. This investigation is of great significance in improving the tribological property of TC4 and suppressing the frictional noise for its wider application in aerospace and automotive fields. Image 1 • SAC and TiC filled into surface dimples can enhance tribological property of TC4. • Frictional noise is closely related to tribological property. • Lubricating layer can repair the worn surface, thus reducing the frictional noise. • TSC-0.6 obtains the best tribological and frictional noise suppression properties. [ABSTRACT FROM AUTHOR]