Fundamentals of optimizing aluminium-based journal bearing materials

2009 ◽  
Vol 223 (5) ◽  
pp. 777-785 ◽  
Author(s):  
F Grün ◽  
I Gódor ◽  
W Eichlseder
Keyword(s):  
Journal Bearing ◽  
Test Procedure ◽  
System Stability ◽  
Pure Aluminium ◽  
Tribological Behaviour ◽  
Soft Phase ◽  
Test Configuration ◽  
Test Methodology ◽  
The Matrix ◽  
Bearing Materials

In this article, a test methodology of model scale is used to visualize the processes taking place during operation and subsequent breakdown in the boundary layer of journal bearing materials. The investigated materials are alloys of aluminium (Al99.6, AlSn20Cu, AlSn40) and tin (SnSb7.5Cu3.5). The utilized test configuration is based on a ring-on-disc system. The employed seizure test procedure was designed in previous studies. The tribometric results clearly show differences in the tribological behaviour between the materials. A series of tests are carried out to explain the observed differences. The frictional surfaces and microsections are observed using microscopy and microindentation. Pure aluminium is characterized both by a potentially low coefficient of friction and an unforgiving overload behaviour. This is due to the fact that components based on pure aluminium tend to lose system stability spontaneously. As more of the soft-phase Sn is added to the matrix, the emergency running properties improve. The system behaves less erratically and the overload behaviour improves. However, the mechanical strength and the wear resistance drop. Tribological functional models summarize the results of tribometrics and damage analysis. These models are the key to further optimization of the materials.

scholarly journals Properties of Journal Bearing Materials That Determine Their Wear Resistance on the Example of Aluminum-Based Alloys

Materials ◽  
2021 ◽  
Vol 14 (3) ◽  
pp. 535
Author(s):  
Alexander Mironov ◽  
Iosif Gershman ◽  
Eugeniy Gershman ◽  
Pavel Podrabinnik ◽  
Ekaterina Kuznetsova ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Wear Resistance ◽  
Journal Bearing ◽  
Tribological Behavior ◽  
Secondary Structures ◽  
Magnesium Content ◽  
Wear Rates ◽  
Relative Extension ◽  
Bearing Materials ◽  
Antifriction Alloys

Potential relations of tribological characteristics of aluminum antifriction alloys with their compositions and mechanical properties were investigated. In this regard, the properties of eight aluminum alloys containing tin from 5.4% to 11% doped with lead, copper, silicon, zinc, magnesium, and titanium were studied. Mechanical properties such as hardness, strength, relative extension, and impact strength were analyzed. Within the tribological tests seizure load and wear of material were evaluated and secondary structures were studied afterwards. The absence of a definitive correlation between tribological behavior and mechanical properties was shown. It was determined that doping tin over 6% is excessive. The seizure load of the alloys increases with the magnesium content. Secondary structures of the alloys with higher wear rates contain one order less magnesium and tin.

A study on tribological behaviour and analysis of ZnO reinforced AA6061 matrix composites fabricated by stir casting route

2021 ◽  
Vol ahead-of-print (ahead-of-print) ◽  
Author(s):  
Sakthi Sadhasivam RM ◽  
Ramanathan K. ◽  
Bhuvaneswari B.V. ◽  
Raja R.
Keyword(s):  
Wear Rate ◽  
Sliding Wear ◽  
Stir Casting ◽  
Industrial Applications ◽  
Wear Behaviour ◽  
Matrix Composites ◽  
Tribological Behaviour ◽  
Content Type ◽  
Zno Particles ◽  
The Matrix

Purpose The most promising replacements for the industrial applications are particle reinforced metal matrix composites because of their good and combined mechanical properties. Currently, the need of matrix materials for industrial applications is widely satisfied by aluminium alloys. The purpose of this paper is to evaluate the tribological behaviour of the zinc oxide (ZnO) particles reinforced AA6061 composites prepared by stir casting route. Design/methodology/approach In this study, AA6061 aluminium alloy matrix reinforced with varying weight percentages (3%, 4.5% and 6%) of ZnO particles, including monolithic AA6061 alloy samples, is cast by the most economical fabrication method, called stir casting. The prepared sample was subjected to X-ray photoelectron spectroscopy (XPS) analysis, experimental density measurement by Archimedian principle and theoretical density by rule of mixture and hardness test to investigate mechanical property. The dry sliding wear behaviour of the composites was investigated using pin-on-disc tribometer with various applied loads of 15 and 20 N, with constant sliding velocity and distance. The wear rate, coefficient of friction (COF) and worn surfaces of the composite specimens and their effects were also investigated in this work. Findings XPS results confirm the homogeneous distribution of ZnO microparticles in the Al matrix. The Vickers hardness result reveals that higher ZnO reinforced (6%) sample have 34.4% higher values of HV than the monolithic aluminium sample. The sliding wear tests similarly show that increasing the weight percentage of ZnO particles leads to a reduced wear rate and COF of 30.01% and 26.32% lower than unreinforced alloy for 15 N and 36.35% and 25% for 20 N applied load. From the worn surface morphological studies, it was evidently noticed that ZnO particles dispersed throughout the matrix and it had strong bonding between the reinforcement and the matrix, which significantly reduced the plastic deformation of the surfaces. Originality/value The uniqueness of this work is to use the reinforcement of ZnO particles with AA6061 matrix and preparing by stir casting route and to study and analyse the physical, hardness and tribological behaviour of the composite materials.

Friction and wear characteristics of fibre-reinforced plastic composites

2018 ◽  
Vol 33 (6) ◽  
pp. 828-850 ◽  
Author(s):  
R Vinayagamoorthy
Keyword(s):  
Friction And Wear ◽  
Wear Behaviour ◽  
Tribological Behaviour ◽  
Reinforced Plastics ◽  
Reinforced Plastic ◽  
The Matrix ◽  
Comprehensive Survey ◽  
Working Parameters ◽  
Sliding Distance ◽  
Friction And Wear Characteristics

The dominance of fibre-reinforced plastics in industries has enhanced the need for research to develop new composites and assess their properties. Among the various property analyses, tribological characteristics of the composites help to understand the friction and wear behaviour. This article presents a comprehensive survey on the tribological behaviour of polymeric composites, which includes the influence of various working parameters such as the velocity of sliding, sliding distance, pressure applied and temperature on the friction and wear. The article also addresses about the importance of the composite constituents such as fibre composition, fibre geometry and fibre orientation on the tribological behaviour. The major reasons causing the tribological failure like the debonding between the fibre and the matrix, failure of the matrix and the fibre are also extensively addressed. This review would be an insight to the industries and tribology researchers towards achieving optimum design for the components made of polymers.

Development of Novel Test Methodology to Understand the Mechanisms of Halite Inhibition and Environmentally Acceptable Halite Scale Inhibitors for High Temperature Application

2014 ◽  
Author(s):  
Kimberley Ho ◽  
Tao Chen ◽  
Ping Chen ◽  
Thomas Hagen ◽  
Harry Montgomerie ◽  
...  
Keyword(s):  
High Temperature ◽  
Test Procedure ◽  
Dynamic Test ◽  
Operation Time ◽  
Field Conditions ◽  
Dynamic Conditions ◽  
Test Methodology ◽  
Static Conditions ◽  
Batch Treatment ◽  
Nucleation Growth

Abstract Halite deposition is most commonly observed in gas/gas condensate fields with low water cut, high TDS produced brines and high temperature. Halite is notoriously difficult to inhibit and there are limited studies focused on halite due to it being incredibly challenging to have an effective test methodology under laboratory conditions that reflect the field conditions. The mechanisms of halite inhibition are unclear. In the published literature, static jar testing is primarily used to evaluate the performance of halite inhibitors. It is not representative of dynamic field conditions and provides limited information of halite inhibition. A new methanol driven dynamic test methodology has been developed alongside a novel jar test procedure, which together provides an effective methodology to evaluate halite inhibition under both static and dynamic conditions and provides an insight into the understanding of the mechanisms of halite inhibition. Using these novel test methodologies, four short-listed inhibitor chemistries including environmentally acceptable inhibitors were assessed and categorised into two types based on the understanding of the mechanism. ➤ Nucleation/growth inhibitors. Inhibitors reduce the nucleation/growth of halite crystals and give good performance under both static and dynamic test conditions.➤ Dispersion inhibitors. Inhibitor doesn't stop the nucleation/growth of halite crystals and gives poor performance under static conditions, but good performance under dynamic conditions due to dispersion effect. Both types of halite inhibitors have been successfully deployed in the fields through continuous injection or batch treatment. Coreflood tests were carried out to confirm the potential risk of formation damage during downhole batch treatment. Other deployment methods have been discussed such as through methanol injection line as both inhibitors are fully methanol compatible. This paper will give a comprehensive study of halite inhibition for challenged wells, including prediction, novel methodology, program of laboratory qualification, mechanism understanding and field deployment, coupled to the development of a chemical technology toolbox to design field halite applications. The value that a fuller understanding of halite control gives the industry is the ability to reduce/eliminate water wash application to control halite formation and so improve well operation time. If halite inhibition is considered at the capex phase of field development, provisions can be made for chemical injection facilities to maintain uninterrupted production.

Stability Analysis of Two-Layered Finite Hydrodynamic Porous Journal Bearing Using Linear and Nonlinear Transient Method

2007 ◽  
Author(s):  
S. K. Kakoty ◽  
S. K. Laha ◽  
P. Mallik
Keyword(s):  
Journal Bearing ◽  
Journal Bearings ◽  
Operating Conditions ◽  
System Stability ◽  
Rigid Rotor ◽  
Transient Method ◽  
Porous Bearing ◽  
Nonlinear Transient ◽  
Linear And Nonlinear ◽  
The Stability

A theoretical analysis has been carried out to determine the stability of rigid rotor supported on two symmetrical finite two-layered porous oil journal bearings. The stability curves have been drawn for different eccentricity ratios and Sommerfeld numbers. The effect of bearing feeding parameter, L/D ratio on the stability is also investigated. This paper also deals with a theoretical investigation of stability using a non-linear transient method. This analysis gives the journal centre locus and from this the system stability can be determined. With the help of graphics, several trajectories of the journal centre have been obtained for different operating conditions. Finally a comparison between single-layered porous bearing and the two-layered porous bearing is presented here.

Numerical and Experimental Research on Periodic Solution Stability of Inclined Rotor Journal Bearing System

2011 ◽  
Author(s):  
Dashuai Qian ◽  
Zhansheng Liu ◽  
Jiajia Yan ◽  
Liquan Sun ◽  
Yongliang Wang
Keyword(s):  
Periodic Solution ◽  
Journal Bearing ◽  
Rotor System ◽  
Experimental Results ◽  
System Stability ◽  
Response Analysis ◽  
Solution Stability ◽  
Special Cases ◽  
Rotor Journal ◽  
Bearing System

Rotor bearing systems on ships usually work in inclined states when ships are swaying in wave and wind. The inclined status will affect the lubricant condition of journal bearing and bring about changes of the dynamic characteristics of the rotor system. To study the periodic solution stability of inclined rotor journal bearing system, Capone’s short bearing model is employed to describe the journal bearing support properties. Considering the inclination induced change of bearing radial load, the dynamic equation of inclined rotor system is established by using finite element method. The periodic solution stability is discussed based on bifurcation and response analysis. With the increase of rotating speed, instability of period-1 motion happens and oil whirl occurs. The motion then develops into a kind of quasi-periodic motion. Two special cases of inclined rotor system, the horizontal and the vertical cases, are compared and discussed. Both of the numerical and the experimental results show that the periodic solution unstable threshold decreases with the increase of rotor inclination angle. At last, some experimental results about influences of experiments conditions on rotor system stability are given.

SELECTION AND EVALUATION OF JOURNAL BEARING MATERIALS THAT ARE BOTH BLOOD-AND-TRIBOLOGICALLY-COMPATIBLE

ASAIO Journal ◽  
1997 ◽  
Vol 43 (2) ◽  
pp. 58 ◽  
Author(s):  
S. F. Murray ◽  
S. Malanoski ◽  
W. Smith ◽  
L. A.R. Golding
Keyword(s):  
Journal Bearing ◽  
Bearing Materials
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