Options
Kamaraj M
Loading...
Preferred name
Kamaraj M
Official Name
Kamaraj M
Alternative Name
Kamaraj, Muthusamy
Kamaraj, M.
Main Affiliation
Email
ORCID
Scopus Author ID
Google Scholar ID
9 results
Now showing 1 - 9 of 9
- PublicationStructure-property correlation in austempered alloyed hypereutectic gray cast irons(15-01-2010)
;Vadiraj, Aravind ;Balachandran, G.; ;Gopalakrishna, B.Prabhakara Rao, K.The austempering behavior of a series of hypereutectic alloyed gray iron compositions with carbon equivalent from 4.37 to 5.14 was studied to understand the influence of microstructure on its mechanical and wear properties. The alloying elements in the alloys included Ni, Mo, Cr and inoculation by micro-constitution of Ti, Nb and Ce. The alloys were austempered at 360 °C and upper bainitic type feathery ferrite was observed in the matrix. While the graphite content determined by optical metallography varied between 16 and 24 vol%. The volume of austenite determined by XRD analysis showed values between 20 and 26%. The ferrite lath size was determined using XRD peak broadening. The tensile property varying between 188 and 270 MPa, showed no significant variation with volume percentage of carbon or austenite in the ausferrite. However the wear rate varying between 0.5 and 2.6 × 10-7 g/Nm, showed a decreasing trend with graphite content attributed to the higher lubricating effect of released carbon during sliding wear. The specific wear rate of hypereutectic alloys, increased with increasing ferrite lath size due to enhanced softer ferrite phase on the sliding surface. The wear rate was found to increase with volume of austenite, austenite carbon content and austenite lattice parameter, which is attributed to increased stability of austenite against strain induced martensite formation and the increased formation of bainitic carbides in the second stage tempering. The various technical aspects in correlating the microstructure with the mechanical and wear properties of hypereutectic austempered gray iron are described. © 2009 Elsevier B.V. All rights reserved. - PublicationMicrostructure and dry sliding wear behaviour of titania and alumina-titania coatings(01-01-2013)
;Vadiraj, A.; Sreenivasan, V. S.The microstructure, hardness and wear properties of atmospheric plasma spray coating of TiO2 and Al2O3-13TiO 2 with incremental hydrogen fractions (11·1-23·8%) in primary gas have been investigated in this work. TiO2 coating shows a fine bead-like surface structure, while Al2O3- 13TiO 2 predominantly exhibits a splat-like morphology. The microstructure shows a slight refinement in the structure for the highest hydrogen content possibly due to the higher specific enthalpy of the plasma plume. Both coatings show the highest hardness for samples coated with the highest hydrogen content possibly due to the refined structure. The roughness shows a mild decreasing trend for TiO2 coating, while the reverse trend is observed for Al2O3-13TiO2 coating. The wear loss and friction coefficient show a flat trend (0·4-0·6) for all the hydrogen contents. The worn tracks show a compacted mixture of ceramic, graphite and metallic particles. © 2013 Institute of Materials, Minerals and Mining. - PublicationStudies on high temperature wear and its mechanism of AlSi/graphite composite under dry sliding conditions(01-11-2010)
;Rajaram, G. ;Kumaran, S. ;Srinivasa Rao, T.Wear behaviours of aluminum silicon alloy and AlSi/graphite composite were investigated at ambient and elevated temperatures. The trend showed a decrease in wear rate with increase in temperature. The reduction in wear rate was mainly attributed to the formation of glazing layer and oxide layer at higher temperature. This was invariably observed in alloy and composites. In addition, the presence of graphite in composite offered better wear resistance for all temperatures under consideration. The wear due to oxidation was predominant during high temperature sliding. © 2010 Elsevier Ltd. - PublicationFriction and wear behavior of surface nanocrystallized aluminium alloy under dry sliding condition(15-04-2010)
;Prakash, N. Arun; One way of improving the surface properties of engineering material is by reducing the grain size at the surface. Controlled ball impact process is developed for producing surface nanocrystallization and improves the surface mechanical properties by inducing compressive residual stress on the metallic materials. Improvement in the surface mechanical properties will affect the tribological properties. This paper reports the influence of the surface nanocrystallization on the tribological properties of aluminium alloy. Tribological properties were evaluated under dry sliding conditions using a reciprocating wear test facility. The friction coefficient of the treated surface is lower than that of the untreated samples and treatment improves the wear resistance of aluminium alloys. The improvement in the friction and wear properties is due to enhancement of surface strength, due to grain refinement and induction of compressive residual stress. The worn surfaces observed using scanning electron microscope reveal the dominant adhesive nature of wear and mild abrasive wear. © 2009 Elsevier B.V. All rights reserved. - PublicationMechanical and wear behaviour of alloyed hypereutectic grey cast iron(01-07-2010)
;Vadiraj, A. ;Balachandran, G.; ;Gopalakrishna, B.Rao, D. V.Alloyed grey cast iron is an important automotive material used in clutch and brake applications. In order to understand the influence of microalloying additives on the graphitic morphology, mechanical and wear behaviour, a series of microalloyed cast iron melts were taken. The laboratory scale ingots made were characterised for microstructure, mechanical properties and wear behaviour. All the cast irons made were hypereutectic with a microstructure consisting of class A type graphite in a pearlitic matrix with eutectic grain boundary carbides. The microalloyed cast irons showed two- to threefold improved wear resistance over a base unalloyed material at comparable mechanical strengths. The wear loss was found to be linear with increasing sliding distance, and the wear resistance is attributed to the combined influence of dense pearlitic matrix with carbides and good distribution of graphite flakes. Cast iron microalloyed with Ni (0.62%) with Ce inoculation showed best overall properties compared to other alloys. © 2010 Maney Publishing. - PublicationEffect of sliding speed on wear behaviour of nitrided martensitic stainless steel under boric acid and MoS 2 lubrication(01-04-2012)
;Vadiraj, A.; Sreenivasan, V. S.Sliding counter bodies frequently undergo boundary lubrication at lubricant starved areas with dominated surface interaction under dry sliding condition. The effect of sliding speed (1.0- 2.5 m s -1) on the friction and wear performance of nitrided martensitic stainless steel in the presence of dry lubricants like boric acid and MoS 2 has been investigated, and the results are presented in this work. Under dry condition, wear loss increases and friction coefficient decreases with sliding speeds. The lubricant coated samples show minimal wear loss at all sliding speeds (2.5 m s -1). The friction coefficient shows a decreasing trend for the MoS2 coated sample, while the boric acid coated sample shows an increasing trend. This is possibly due to the temperature induced conversion of boric acid to boric oxide. The fine debris mixture formed during sliding may also pin the lamellar shearing of solid lubricants to increase friction. © 2012 Institute of Materials, Minerals and Mining. - PublicationA study on influence of aging treatment on sliding wear resistance of a nickel based hardfacing alloy(01-10-2011)
;Kesavan, D.In the present study, Ni-based Colmonoy 5 was deposited on Type 316L (N) stainless steel. The deposit was aged at 580 and 650°C for 5,000 h to study the influence of aging on sliding wear resistance. The aged deposits show more wear loss due to reduced hardness. However, the reduced hardness after aging was not reflected on wear test at 550°C irrespective of sliding distance. This is due to stability of microstructure as well as the generation of oxide layer during high temperature tests. Subsequently, an empirical relation was developed based on outcome experimental data using full factorial design of experiments in terms of hardness (H), test temperature (T) and sliding distance (D). Based on the empirical relation, it was found that the test temperatures (T) play a predominant role on wear loss than hardness (H) and sliding distance (D). Further, the developed relationships were validated using analysis of variance (ANOVA). © 2011 Indian Institute of Metals. - PublicationInfluence of load and sliding speed on friction and interface temperature of hypereutectic alloyed gray cast iron(01-06-2012)
;Vadiraj, Aravind; Sreenivasan, V. S.The influence of incremental sliding speeds and normal loads on friction, wear and interface temperature have been investigated on a series of hypereutectic alloyed gray cast irons. Mass loss and friction coefficient values show inverse trend with sliding speeds. The interfacial temperature increases with incremental speeds and loads while the friction coefficient decrease with the same. The alloys with higher volume of graphite show slightly lower interfacial temperature due to higher thermal transport capacity. The conjoint interaction of asperities and debris possibly predominates at lower speeds and higher mass loss predominates at higher sliding speeds. © Indian Institute of Metals 2012. - PublicationInvestigations on the temperature-dependent tribological behaviour of spark plasma sintered CNT-304 SS self-lubricating nanocomposites(01-01-2023)
;Radhamani, A. V. ;Bhaumik, Shubrajit ;Lau, Hon Chung; Ramakrishna, S.Herein, we report the tribological behaviour of CNT-304 stainless steel composites at room (28°C) and high temperatures (200°C). Nanocomposites of various CNT concentrations, namely 0.2, 0.5, 1.0, 2.0, 3.0, and 4.0 wt%, were prepared. A significant amount of grain refinement resulted in an increase in CNT loading. A tribological study was carried out at 28°C and 200°C. Wear resistance was found to enhance with an increase in CNT concentration at both temperatures. However, a slightly higher wear rate was observed at 200°C for the samples with CNT content < 3 wt% than their corresponding low-temperature values. About 86%, 91% drop-in wear rate was seen in 2.0 wt% CNT-304 SS, and 4.0 wt% CNT-304SS, respectively, as compared to pure SS at 28°C, which is 54% and 88% decrease at 200°C and is very promising. The decrease in wear volume with CNT content at both temperatures can be ascribed to the self-lubricating and reinforcing nature of CNTs in the metal matrix composites. Severe abrasive wear in the pristine SS samples was slowly changed to mild abrasive and lubricated wear in composites. A systematic study on the tribological behaviour of CNT-SS composites can shed light on the benefits and detriments of using them for various applications. Highlights Incorporation of CNTs into 304 SS matrix caused grain refinement. Wear rate decreased with CNT content and 4.0 wt% CNT-SS showed minimum wear rate while pristine gave the maximum at both 28°C and 200°C. About 86% and 54% decrease in wear rate were observed for 2.0 wt% CNT-304 SS at 28°C and 200°C respectively as compared to the pristine 304 SS sample. Wear rate at 200°C was slightly more than that of room temperature (28°C) for CNT content < 3 wt%. The 3.0 wt% CNT-304 SS and 4.0 wt% CNT-304 SS showed nearly the same wear rate at both ambient and 200°C test.