Tribological Behavior of Bronze Alloys with Solid Lubricants

2012 ◽  
Vol 527 ◽  
pp. 205-210 ◽  
Author(s):  
Marke Kallio ◽  
Petri Vuorinen ◽  
Elena Fuentes ◽  
Oscar Maraña ◽  
Viivi Ruusila ◽  
...  

Lead containing bronzes are widely used as bearings, bushings and sliding plates. Lead is a heavy metal and known to be harmful to people and environment, but currently no feasible substitute material exists in many engineering applications. The ecological considerations in recent years have led to restrictions by the European Commission on the use of lead for example in the bearings used in cars (The Directive on the end-of-life of vehicles). However, due to the lack of substitutes for lead in many application areas, the ban has been given an exemption. The aim of the ECOBEARINGS project was to evaluate, whether any metallic or composite bearing material has similar tribological and mechanical properties as the currently used standard lead bronzes. In heavy machine engineering, lead bronze alloys containing up to 10-20 % of Pb are commonly used as sliding bearings such as thrust and journal bearings. In lead bronzes, lead has a function of a solid lubricant especially during the start of the operation of the bearing. Additionally, lead bronzes form a soft sliding surface where small contamination particles can be embedded in the material without causing an abrasive effect. A variety of different lead-free bearing solutions are already commercially available, but there are many applications where the emergency lubricating properties of lead cannot be substituted yet. It has been proposed that other solid lubricants such as graphite or bismuth could possibly have similar tribological characteristics as lead in bronze bearing materials. In this work, bronze alloys containing solid lubricants such as bismuth and graphite were produced by casting and spray forming. The alloys were characterized and tribologically tested in boundary lubricated and dry sliding conditions. The results were compared with the testing results of lead bronze. On the basis of the results, it was noted that different solid lubricants have very special tribological characteristics. This information can be used in the further development of ecologically sound bearing materials.

1965 ◽  
Vol 87 (3) ◽  
pp. 791-804
Author(s):  
M. B. Peterson ◽  
T. E. Timkens ◽  
R. D. Brown ◽  
R. A. Burton ◽  
E. E. Klaus ◽  
...  

In this review the developments in the fields of lubricants, friction, and bearing materials have been summarized by various authorities in each particular field. The review covers the period from June to December, 1963. The developments in bearings and gears will be published at a later date. Much of the published work is concerned with high temperature and vacuum conditions. However, it is of interest to note the large increase in the published work in solid lubricants over that of previous years.


Author(s):  
Kevin Jupe ◽  
Roger Gorges ◽  
Anil Rathod ◽  
John Carey ◽  
John Stearns

The move to lead-free bearing materials is well known and upcoming legislation, such as the Restriction of Hazardous Substances (RoHS), is increasing the drive to extend this trend towards heavy duty diesel truck and off-highway applications. During the development of lead-free systems, new electroplated overlays and bronze-based substrates have been developed by various suppliers, but little attention has been given to the interlayer or diffusion barrier between the overlay and substrate materials. This interlayer is particularly necessary for tin-based solutions as it prevents the rapid diffusion of overlay species into the bronze substrate. The present development focuses on improving this often overlooked element in the system and provides a further robustness that could even be adapted to lead-based systems where increased performance is required. The incorporation of hexagonal boron nitride as a solid lubricant in the nickel interlayer changes dramatically the interlayer properties and provides more typical bearing-like behavior for seizure resistance scuff performance compared to nickel alone. The paper details findings of respective rig tests as well as an actual engine test supporting the change in material characteristics and the associated improvement in seizure resistance.


2021 ◽  
pp. 435-444
Author(s):  
Harish Hirani

Abstract A mechanical part, which supports the moving part, is termed a mechanical bearing and can be classified into rolling (ball or roller) bearings and sliding bearings. This article discusses the failures of sliding bearings. It first describes the geometry of sliding bearings, next provides an overview of bearing materials, and then presents the various lubrication mechanisms: hydrostatic, hydrodynamic, boundary lubrication, elastohydrodynamic, and squeeze-film lubrication. The article describes the effect of debris and contaminant particles in bearings. The steps involved in failure analysis of sliding bearings are also covered. Finally, the article discusses wear-damage mechanisms from the standpoint of bearing design.


2012 ◽  
Vol 496 ◽  
pp. 355-358 ◽  
Author(s):  
You Qiang Wang ◽  
Li Jing Zhang

Thordon is a new liner material used widely in water-lubricated bearings in virtue of its shockproof characteristic, high load and wear resistance. The category of materials used in water-lubricated bearings was briefly outlined and tribological characteristics of most of the materials were compared in the paper. The defects of the traditional water-lubricated bearing materials were listed and the advantage of the Thordon bearing was presented. The development status and the tribological characteristics of the water-lubricated Thordon bearings were studied. The application prospects of the water-lubricated Thordon bearings were introduced in the end of the paper.


1977 ◽  
Vol 16 (1) ◽  
pp. 67-70 ◽  
Author(s):  
I. M. Fedorchenko ◽  
V. A. Konchakovskii ◽  
V. N. Miroshnikov ◽  
V. I. Kiryukhin ◽  
I. D. Yampol'skii

Sign in / Sign up

Export Citation Format

Share Document