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Purpose: The grain size and grain distribution mode have a significant impact on the tribological properties of Babbitt alloy. The purpose of this paper is to study the effect of differentiated SnSb grain size distribution on the improvement of tribological properties of Babbitt alloy. Design/methodology/approach: Babbitt (marked by babbitt-cr), with a differentiated SnSb grain size distribution, was fabricated using a selective zone laser surface treatment. Bare Babbitt with coarse SnSb grain was marked as babbitt-c, and Babbitt with refined SnSb grain was marked as babbitt-r. The microstructure, microhardness and wettability of specimens were tested. The tribological properties of babbitt-c, babbitt-r and babbitt-cr were evaluated under dry and lubricated conditions. Findings: The microstructure transforms from single coarse SnSb grain distribution or single refined SnSb grain distribution to differentiated SnSb grain size distribution, as a result of selective zone laser surface treatment. Among three specimens of microhardness, babbitt-cr showed the highest microhardness. The lipophilicity property of babbitt-cr was better compared to babbitt-c. A mixture of coarse and refined grain is beneficial to improve the tribological properties of Babbitt alloy under dry condition. Furthermore, compared with babbitt-c, the wear resistance of babbitt-cr was enhanced under lubricated condition. However, the anti-wear property of babbitt-cr was not significantly improved relative to babbitt-r with an increase in the loads. Originality/value: The study demonstrates that modulated different grain size alternating distribution modes can improve the tribological properties of Babbitt alloy. Peer review: The peer review history for this article is available at: https://publons.com/publon/10.1108/ILT-09-2022-0259/ [ABSTRACT FROM AUTHOR]

Purpose: This paper aims to study different morphology Cu6Sn5 effect on Babbitt alloy tribological properties. Design/methodology/approach: Different morphology Cu6Sn5 of Babbitt was conducted by different cooling modes. Bare Babbitt was marked by Babbitt-0, Babbitt modified by first cooling mode (marked by Babbitt-1) and Babbitt modified by second cooling mode (marked by Babbitt-2). The microstructure and microhardness of specimens were tested. Then, tribological properties of Babbitt-0, Babbitt-1 and Babbitt-2 were performed by reciprocating mode under lubricated condition. Findings: The results showed that shape Cu6Sn5 of Babbitt was changed from mixed needle and star-like shape to short rod-like or granular shape. The microhardness of Babbitt-1 was highest than that of Babbitt-0 and Babbitt-2. Compared with Babbitt-0 and Babbitt-2, tribological properties of Babbitt-1 were better under lubricated condition due to short rod-like and sparse distribution of Cu6Sn5. Moreover, the simulation result of strain and stress of Babbitt-1 was lowest than that of Babbitt-0 and Babbitt-2. Originality/value: Different morphology (shape and distributed) of Cu6Sn5 was obtained by different cooling modes. Modulated different forms of Cu6Sn5 around SnSb was beneficial to improve Babbitt alloy tribological properties. [ABSTRACT FROM AUTHOR]

Purpose: This study aims to improve the tribological performance of Babbitt alloy under oil lubricant condition. Thus, the surface was treated into oleophobic state by modifying with low surface energy fluorosilane (1H,1H,2H,2H-perfluorodecyltriethoxysilane). It is believed that the oleophobic surface offered excellent wear resistance of Babbitt-based tribo-pairs. Design/methodology/approach: By modifying the Babbitt alloy with low surface energy fluorosilane and measuring the oil contact angle, the wetting behavior was evaluated. Using Pin on Disk tribometer, the tribological properties of bare Babbitt and modified Babbitt were quantified. The samples after the friction test were characterized by scanning electron microscope (SEM) and the anti-wear performance was evaluated under dry and oil lubrication conditions. Findings: Results showed that oil contact angle of modified Babbitt was109° which was tripled compared to that of prime surface, which indicates the oleophobic behavior was greatly improved. Under dry conditions, the friction coefficient of the modified surface with different load conditions is slightly lower than that of the bare surface, while the friction coefficient of the modified surface under lubrication conditions is significantly decreased compared to that of the bare surface. Interestingly, under low load and high load, the wear rate of the modified Babbitt alloy surface is only 1/4 and 1/3 of that of the bare surface, respectively. Originality/value: The work proposed an effective method to improve the Babbitt tribological performances and will lighten future ideas for the Babbitt alloy bearing with high wear resistance, which is beneficial to improve the service life of sliding bearings and has huge promotion and application value in the manufacture of sliding bearings. [ABSTRACT FROM AUTHOR]

Purpose: Babbitt bush is easy to cause severe adhesive wear due to unexpected journal fall. This paper aims to improve wear resistance of Babbitt bush. Design/methodology/approach: A soft/hard hybrid surface mircoprofile of Babbitt alloy/steel was fabricated by a technology of laser texture combined with hot-pressing. The friction and wear performances of bare steel (steel-h), Babbitt bush on steel (steel-s) and Babbitt filled in dimples of steel (steel-hs) were conducted on a ball-on-disc tester under dry and lubricated conditions. Findings: The results showed that wettability of steel-hs was enhanced by forming soft/hard hybrid surface. Compared with steel-s, the stability of friction coefficient curve of steel-hs was improved without increasing coefficient friction. The wear resistance of steel-hs was remarkably enhanced under dry and lubricated conditions. Originality/value: The originality of this paper is as following: to improve the tribological properties and to prolong service life of steel-s, soft/hard hybrid surface of Babbitt filled in dimples of steel substrate was successfully fabricated by laser texturing combined with hot-pressing. This paper showed that the lipophilicity of steel-hs was best among those of steel-s and steel-h. Babbitt alloy as a soft filler on dimples of steel substrate improved anti-wear of steel-s remarkably. It provides a new way to fabricate Babbitt as bushing on steel substrate. [ABSTRACT FROM AUTHOR]

Carbon fabric reinforced phenolic-based composites (CF/PF composites) often act a potential alternative to traditional materials which currently used in machine elements such as self-lubricating bearing, high-performance gears, and movable sealed. In the present study, the CNTs@MoS2 hybrids were synthesized by hydrothermal method, which were used as additives for their optimal wear resistance and lubricating properties in order to enhance the tribological properties of CF/PF composites. We found that the CF/PF composites with varying contents of CNTs@MoS2 hybrids showed improved self-lubricating properties under different sliding conditions, and the friction coefficient decreased as the content of additives increased. Nevertheless, the doping of 1 wt% hybrids decreased the wear resistance of CF/PF composites due to the occurrence of severe abrasive wear caused by peeling off of matrix in relatively large volume. However, with the contents of hybrids increased to 2 wt% and 4 wt%, the CF/PF composites exhibited improved wear resistance. The mechanism of wear resistance could be attributed to the excellent mechanical properties of CNTs and strong interfacial bonding force between hybrids and matrix as well as the formation of MoS2 transfer film on the surface of counterpart. [ABSTRACT FROM AUTHOR]

Babbitt alloy is a widely used bearing material. In order to improve its thermal and anti-fatigue performance, the combined effect of additive La and heat treatment of tin-Babbitt were studied. The microhardness, wettability, and tribological performances of the Babbitt were first considered. The Babbitt alloy modified with La element (0.1 wt%) was prepared and then heat treatment was carried out (marked by the modified Babbitt). The friction and wear performances of the bare Babbitt, heated Babbitt, and modified Babbitt were conducted by a ball-on-disc tester under oil lubricated condition. The results showed that the microstructure of the modified Babbitt alloy was homogeneous. The cubic phase of SnSb intermetallic was refined and the SnSb cubes were also passivated. The microhardness of the modified Babbitt increased from 24.67 Hv to 37.84 Hv and wettability was improved with the addition La and heat treatment. Therefore, the anti-wear performance of the Babbitt was improved. The modified Babbitt alloy is observed to resist the instant scratching from the journal. [ABSTRACT FROM AUTHOR]

In this paper, an unbalanced Jeffcott rotor supported by the roller bearings is modelled, and the dynamic differential equations are obtained by the Lagrange’s equations. The fourth order Runge–Kutta method is employed to simulate this system in two cases. Simulation results show the combined effect of the coupled lateral and torsional vibrations and the variable compliance vibration of the rotor. In the case of that only a large and constant radial force is applied, the sum and difference between variable compliance and rotational frequency components of the torsional vibrations of the disk are induced because of the roller bearings’ rotation. And when they are near to the natural frequency of the torsional vibration, the resonance peaks appear. In the case of that a large and constant radial force and a harmonic torque are simultaneously applied, the two components, the sum and difference between rotational frequency and the frequency of the external torque, of the lateral vibrations of the disk are induced. When the frequency of the external harmonic torque approximatively equal to a special value, the two frequency band lines, variable compliance and the sum of rotational frequency and the frequency of external torque, intersect near the natural frequency of the lateral vibration, and the vibration may aggravate. [ABSTRACT FROM AUTHOR]