Sintered steels containing molybdenum di sulphide powders were developed for application as bearings, gears, connecting rods, etc. Abrasive wear characteristics of these materials are investigated as the machine elements also need to have a good abrasive wear resistance. Materials with base composition Fe-C-Cu and Fe-C-Cu-Ni containing varying levels of MoS2 were developed from elemental powders. Compressive strength, hardness and density are influenced by the addition of MoS2. Abrasive wear tests were conducted by sliding against the SiC abrasive sheet at room temperature. MoS2 added material exhibited a high coefficient of friction and good wear resistance compared to the base composition. The artificial neural network model developed predicts the wear volumes, which are in agreement with the experimentally measured data. © 2006 Elsevier B.V. All rights reserved.

Rajappa Gnanamoorthy

Department of Mechanical Engineering

S. Dhanasekaran

Abrasion

Hardness

Mathematical models

Neural Networks

Sintering

Wear of materials

Wear resistance

abrasive wear

MOS2 ADDITION

SINTERED STEELS

Steel

IIT Madras is a public technical and research university located in Chennai, Tamil Nadu. Founded in 1959, it is recognised as an Institute of National Importance.

IIT Madras has been ranked as the top engineering institute in India for four years in a row by the National Institutional Ranking Framework of the MHRD

It currently offers undergraduate, postgraduate and research degrees across 16 disciplines in Engineering, Sciences, Humanities and Management. About 596 faculty belonging to science and engineering departments and centres of the Institute are engaged in teaching, research and industrial consultancy.

IIT Madras

Wear

In this study, a wear prediction methodology for spur gears is employed to investigate the influence of material properties on gear tooth wear under unlubricated conditions. The methodology employs a single point observation-based gear contact mechanics in conjunction with the Archard's wear formulation to predict the tooth wear and wear pattern in spur gears. A MATLAB program is developed to account the changes in the gear contact per mesh cycle as the wear occurs. The material containing 3% MoS2 is found beneficial in improving the wear resistance. Wear is more both in addendum and dedendum tooth surfaces, and that the highest wear occurs at the dedendum of tooth surface. Results of the experimental study are presented for validation of wear prediction methodology. © 2007 Elsevier B.V. All rights reserved.

Gear tooth wear in sintered spur gears under dry running conditions

Components subject to relative motion induces wear on mating surfaces. The wear characteristic of porous materials is entirely different from the wrought materials and is mainly influenced by the pores present in the materials. In this context, study on wear characteristic of P/M alloy steels having wide applications in automotive, manufacturing industries, and subject to relative motion with another is a prime important. Addition of alloying elements play significant role on changing wear characteristic of base material. Titanium is one of the alloying elements, which forms hard secondary phase in microstructure. The present work aims to study the influence of titanium addition on dry sliding wear characteristic of sintered/forged plain carbon steel (Fe-1%C). The Ti alloyed steel offers greater wear resistance compared to plain carbon steel. Wear loss increases with increase in normal applied load irrespective of the P/M alloy steels. Delamination is a common wear mechanism found in both the alloy steels. It is observed from the wear pattern and Scanning Electron Microscope (SEM) images that the presence of hard phase micro-element of the alloying element are embedded in the soft ferritic matrix of Fe-C attributes to non-uniform wear for the Ti alloyed P/M plain carbon steel. © 2017 Elsevier Ltd. All rights reserved.

Materials Today: Proceedings

Experimental study on dry sliding wear characteristics of sintered/forged plain carbon steel (Fe-1%C) with the addition of Titanium

Sintered steels find increasing application as bearings and gears due to economical and technical reasons. Materials used for making these machine elements need to have high strength, good wear resistance and low coefficient of friction. An attempt is made to develop molybdenum di sulphide added iron-copper-carbon sintered steels using simple single stage compaction and sintering elemental powders. Friction and wear characteristics of the developed materials were evaluated using cylindrical specimens in a pin-on-disc sliding apparatus. Addition of molybdenum di sulphide increases the compressibility and increases the part density. Strength and hardness of the molybdenum di sulphide added compositions are better than the base composition. Addition of the 3% molybdenum di sulphide is found to be beneficial in improving friction and wear characteristics. Higher amount of brittle phases in the 5% molybdenum di sulphide added sample contributes to the reduction in the wear resistance. © 2006.

Materials and Design

Dry sliding friction and wear characteristics of Fe-C-Cu alloy containing molybdenum di sulphide

Powder metal processing permits development of new composites with specific properties required for demanding applications. Complex shaped machine elements like gears and bearings are made of powder metallurgy technique economically. In many applications these machine elements operate under unlubricated conditions and there is a need for materials with good friction and wear characteristics, strength and modulus. In the present study, Fe-C-Cu-Ni alloys with solid lubricant, MoS2, were developed using a simple single stage compaction and sintering. The microstructure, strength, hardness and tribo behavior of the composites were evaluated. The friction and wear characteristics were evaluated using pin-on-disc type tribo test machine. Addition of solid lubricant improved the compressibility and thereby the density of the compacts. Presence of the secondary sulphide phases in the as-sintered compacts improves the hardness and strength. The coefficient of friction and wear loss decreased with addition of MoS2. A simple wear model is proposed to predict the wear loss in these composites. The model predicts wear loss values that are in agreement with the experimental data. © Springer Science+Business Media, LLC 2007.

Journal of Materials Science

Microstructure, strength and tribological behavior of Fe-C-Cu-Ni sintered steels prepared with MoS2 addition

Polymer nanocomposites are particle-filled polymers in which at least one dimension of the dispersed particles is in the nanometer range. Dispersing nanosize particles in a polymer matrix induces superior mechanical properties compared to traditional macro fillers. Nanolevel reinforcement also affects the tribological properties and needs to be clearly understood before using in practical applications. Friction and wear characteristics of Nylon 6 nanocomposites under dry sliding conditions are reported in this paper. Nylon 6 with 5% organoclay was prepared by melt intercalation technique. The tensile behaviour is evaluated according to ASTM standards. A pin-on-disc type tribometer is used for evaluating the friction and wear behaviour. It is found that the Nylon 6 nanocomposites have superior tribological properties than unfilled polymer. Formation of uniform tenacious transfer layer by Nylon 6 nanocomposite on the counterface contributes to the reduction in coefficient of friction and specific wear rate. Nylon Nancomposites exhibited high wear resistance compared with the neat Nylon. © 2005 Springer Science + Business Media, Inc.

Effect of nanoclay reinforcement on tensile and tribo behaviour of Nylon 6

Powder metal processed gears and bearings find increasing application in automotive and other engineering industries. Failure of these machine elements is mostly due to the presence of sliding action in addition to the prevailing rolling action during transmission of motion and power. This rolling-sliding contact fatigue behavior of sintered and hardened steel rollers was investigated using a test machine designed and developed in the laboratory. Sintered and hardened steel rollers were mated against the hardened wrought tool steel roller at different slide-roll ratios and contact stresses. Contact stress versus number of cycles-to-failure data was generated under drop lubrication conditions. An increase in slideroll ratio significantly affected the life of the rollers at all contact stress levels investigated. Failed surfaces were analyzed using the optical microscope. Significant peeling-type failure was observed in the specimens tested, but no marked difference in the failure appearance was noted due to the introduction of traction forces. © ASM International.

Journal	Wear
ISSN	00431648
Open Access	No