Search results

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.

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.

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.

The study demonstrates that modulated different grain size alternating distribution modes can improve the tribological properties of Babbitt alloy.

The peer review history for this article is available at: https://publons.com/publon/10.1108/ILT-09-2022-0259/

This paper aims to study different morphology Cu₆Sn₅ effect on Babbitt alloy tribological properties.

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.

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.

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.

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.

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.

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.

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.

Babbitt bush is easy to cause severe adhesive wear due to unexpected journal fall. This paper aims to improve wear resistance of Babbitt bush.

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.

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.

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.

Low friction polymer coatings able to withstand high loadings and many years of continuous operation are difficult to formulate at low cost, but could find many applications in industry. This study aims to analyze and compare friction and wear performance of novel polydopamine/polytetrafluoroethylene (PDA/PTFE) and traditional tin Babbitt coatings applied to an industrial journal bearing.

This paper tested PTFE based coating, co-deposited with PDA, a biopolymer allowing sea mussels to adhere to ocean rocks. This coating was deposited on flat steel substrates and on a curved cast iron hydrodynamic journal bearing surface. The flat substrates were analyzed with a tribometer and an optical microscope, while the coated bearing liners were tested in an industrial laboratory setting at different speeds and different radial loads.

PDA/PTFE coating showed 2-3 times lower friction compared to traditional tin Babbitt for flat substrates, but higher friction in the bearing liners. PDA/PTFE also showed considerable wear through coating delamination and abrasion in the bearing liners.

Five future modifications to mitigate coating flaws are provided, which include modifications to coating thickness and its surface finish.

While the novel coating showed excellent results on flat substrates, coating performance in a large scale bearing was found to be poor. This study shows that coating preparation needs to be improved to avoid frictional losses and unwanted damage to bearings. We provide several routes that could improve coating performance in industrial applications.

A self-lubricant surface composite including Al matrix and Babbitt alloy 11 reinforcement has been fabricated via friction stir processing (FSP).

The optimum processing condition is estimated by statistical analysis of a L9 Taguchi design of experiment. The results of Taguchi analysis suggested four passes of FSP, traverse speed of 40 mm/min and rotational speeds of 1,250 rpm as the optimum parameters to achieve higher hardness and wear resistance.

The needle-shaped particles are fragmented into the finer particles after FSP. There is uniform distribution of precipitations after FSP. The microhardness of manufactured surface bearings has been increased. Finer particles, smaller grains and in situ formed intermetallic precipitations (AlSb) can be responsible for hardness enhancement. Wear resistance of base metal also has been remarkably enhanced after FSP.

The originality of this paper lies in the following: new self-lubricating surface composite; a tough and resistant to wear sheets; and using a solid-state method to fabricate a surface bearing.

In the last few years bearing research has begun to open a new field of information on the effects of solids in the oil to sleeve bearings. Actually, we are just beginning to evaluate some of the design conditions that have existed for years. It is, therefore, no longer sufficient merely to state that a given solid is good or bad for bearing lubrication—we also must know how good or how bad the effects of the solid will be on a certain bearing material. A series of tests on babbitt bearings was reported in June, 1952. Continued research on copper‐lead and aluminium operating with particles of molybdenum sulphide, rouge, and corundum has shown some very significant effects on the bearing's friction and load‐carrying capacity. The authors are respectively Associate Professor, Dept.Mech.Eng., and Research Engineer, Defence Research laboratory, University of Texas, and this paper was presented at a Joint Session of the Machine Design Division and Lubrication Activity at the September, 1954, Meeting of the American Society of Mechanical Engineers.

For oil film thickness measurement using ultrasonic spring model, obtaining the isolated reflection from the oil film layer is the key point. While for oil film thickness measurement in thrust bearings with thin liner, the reflection from the substrate-Babbitt interface will overlap with the reflection from the oil film layer. This overlapping will render the ultrasonic spring model invalid. To obtain the isolated reflected signal from the oil film layer accurately, an adaptive method was developed to recover the overlapping echoes.

A genetic-algorithm-based support matching pursuit (GA-based SMP) was developed to provide the optimal echo number and initial parameters guesses automatically and efficiently. Then, the traditional expectation maximization (EM) model was used to fine tune the accurate results.

The developed method was tested using both simulated echoes and the overlapping echoes encountered in the ultrasonic oil film thickness measurement of thrust bearings. The results demonstrated that the developed method performed well on recovering overlapping echoes adaptively.

The work shows an adaptive method to recover the ultrasonic overlapping echoes. When used in ultrasonic oil film thickness measurement, it can help extend the application of traditional ultrasonic spring model to objects with four or more layers.

Bearings and exhaust valves are components of vital importance to the engine of a motor‐car. They operate under conditions which favour corrosive attack, and the problem of mitigating this attack is made more difficult, in the case of the bearings, by the tendency towards increasing engine power and, in the case of the exhaust valves, by the use of petrols containing tetra‐ethyl lead. Previous articles by Mr. Michalewicz in this series have appeared in CORROSION TECHNOLOGY in the issues of August 1954 (‘Corrosive Wear of Piston Rings and Cylinders’), November 1954 (‘The Cooling System’) and March 1955 (‘The Bodywork’).

This study aims to introduce moral re-armament’s (MRA) role as a mediator in several labor/management disputes in industries primarily in the 1940s and 1950s. In this study, MRA was guided by a social responsibility framed in language that was a precursor to corporate social responsibility (CSR). This study features the case of the Miami-based airlines serving Latin America, who had experienced the longest airline labor strike to that date.

In this study, both artifacts and literary interpretations are used to inform an institutional-theory-based approach to a broad social movement, one player in that movement and its impact on an industry. Actions at one time can be shown to relate to activity and behavior at another time (Wadhwani and Bucheli, 2014). Thus, this paper has combined these perspectives in the approach to historically examine a precursor phenomenon of CSR.

MRA’s approach shared some methods, such as story-telling, with modern change management. This paper proposes that other methods that were important for that historical context played a significant role in MRA’s success. Today, these methods are no longer used. These include “intimacy” (MRA employees lived with members of labor and management while they were mediating), “theater” (they showed plays to all of those involved) and confessional sharing (their training was mostly a series of testimonies by those who previously were combative, but became collaborative when they accepted MRA’s principles).

This historical case may inspire those promoting CSR to expand their methods to have even greater success today.