T. Ramesh

Bio: T. Ramesh is an academic researcher from National Institute of Technology, Tiruchirappalli. The author has contributed to research in topics: Welding & Laser beam welding. The author has an hindex of 16, co-authored 40 publications receiving 661 citations. Previous affiliations of T. Ramesh include J. J. College of Engineering and Technology.

Some aspects on workability of aluminium–iron powder metallurgy composite during cold upsetting

Abstract: Workability is a measure of the extent of deformation that a powder metallurgy materials can withstand prior to fracture occurred in the forming or upsetting processes Ductile fracture is the most common mode of failure in bulk forming process The formability is a complicated phenomenon, dependent upon the process as well as the material parameters A complete experimental investigation on the workability behaviour of Al–Fe composite was performed under the triaxial stress state Upsetting of Al–Fe composite having different iron contents with different aspect ratios and iron particle sizes were carried out and the formability behaviour of the compacts at triaxial stress condition was determined A new true strain considering the effect of the bulging was taken in to account The curves plotted for different compacts were analyzed and concluded that there is a drastic changes in the formability behaviour of compacts because of different content of iron and its particle sizes and aspect ratios

Effect of particle size of SiC in aluminium matrix on workability and strain hardening behaviour of P/M composite

Abstract: A complete experimental investigation on workability behaviour of the Al–SiC has been carried out during cold upsetting. The present study has been performed to evaluate the effect of particle size of silicon carbide addition in P/M preforms of Al–SiC composite on workability studies. The material studied in this paper is aluminium with SiC reinforcement. SiC content has been varied from 0% to 20% with different particle sizes namely 50, 65 and 120 μm. The experimental results were analyzed for workability under triaxial stress state condition as a function of the relative density. The formability stress index ( β ), stress ratio parameters namely σ θ / σ eff and σ z / σ m , strain hardening index ( n ) value and strength coefficient ( K ) value were obtained for each percentage addition of SiC and its particle sizes. It is found that these parameters have shown tremendous variations in their values for different particle sizes and percentage content of SiC.

Optimization to develop multiple response hardness and compressive strength of zirconia reinforced alumina by using RSM and GRA

Abstract: In this work the effect of powder forming process parameters of zirconia reinforced alumina composites on micro hardness and compressive strength was studied. The weight percentages of zirconia added to alumina, compaction pressure and sintering temperature are the process parameters selected for this analysis. Using Box–Behnken technique in Response Surface Methodology (RSM), seventeen experimental runs are developed. The sintering temperature and weight percentage of zirconia added to alumina are found to influence the responses. The influencing parameters were identified by using analysis of variance and Grey Relational Analysis (GRA). The regression model for both micro hardness and compressive strength are developed. The increasing amount of zirconia added to alumina matrix is found to enhance the compressive strength of the composite and reduces the hardness of composite. Also, multi response optimization to obtain higher hardness and compressive strength are done using both RSM and GRA.

Interface design for high energy density polymer nanocomposites

Abstract: This review provides a detailed overview on the latest developments in the design and control of the interface in polymer based composite dielectrics for energy storage applications. The methods employed for interface design in composite systems are described for a variety of filler types and morphologies, along with novel approaches employed to build hierarchical interfaces for multi-scale control of properties. Efforts to achieve a close control of interfacial properties and geometry are then described, which includes the creation of either flexible or rigid polymer interfaces, the use of liquid crystals and developing ceramic and carbon-based interfaces with tailored electrical properties. The impact of the variety of interface structures on composite polarization and energy storage capability are described, along with an overview of existing models to understand the polarization mechanisms and quantitatively assess the potential benefits of different structures for energy storage. The applications and properties of such interface-controlled materials are then explored, along with an overview of existing challenges and practical limitations. Finally, a summary and future perspectives are provided to highlight future directions of research in this growing and important area.

Analysis of dry sliding wear behaviour of Al6061/SiC/Al2O3 hybrid metal matrix composites

Abstract: This paper presents the wear behaviour of Al6061-T6 discontinuously reinforced with silicon carbide (SiC) and aluminium oxide (Al2O3) composite. The test specimens are prepared and tested as per ASTM standard. The experiments are conducted by using a pin on disc wear tester. Empirical relation is established to estimate the wear using statistical regression analysis and analysis of variance (ANOVA). The results indicated that the wear resistance of the 15% hybrid composite is better than that of the 5% composite. The fracture surface of composites shows the ductile tear ridges and cracked SiC and Al2O3 particles indicating both ductile and brittle fracture mechanism.

Investigation of particle size and amount of alumina on microstructure and mechanical properties of al matrix composite made by powder metallurgy

Abstract: Al matrix composite is well known, in which Al2O3 is the most widely used reinforcement. The aim of this study is to investigate the effect of alumina particle size and its amount on the relative density, hardness, microstructure, wear resistance, yield and compressive strength and elongation in Al–Al2O3 composites. To this end, the amount of 0–20 wt.% alumina with average particle sizes 48, 12 and 3 μm was used along with pure aluminum of average particle size of 30 μm. Powder metallurgy is a method used in the fabrication of this composite in which the powders were mixed using a planetary ball mill. Consolidation was conducted by axial pressing at 440 MPa. Sintering procedure was done at 550 °C for 45 min. The results indicated that as the alumina particle size is reduced, density raises at first, then, declines. Moreover, as the alumina particle size decreases, hardness, yield strength, compressive strength and elongation increase and factors such as wear resistance, microstructure grain size and distribution homogeneity in matrix decreases. For instance, as the alumina particle size gets smaller from 48 to 3 μm at 10 wt.% alumina, hardness rises from 50 to 70 BHN, compressive strength improves from 168 to 307 MPa and wear rate rises from 0.0289 to 0.0341 mm3/m. On the other hand, as the amount of alumina increases, hardness and wear resistance increase and relative density and elongation is decreased. However, compressive and yield strength rise at first, then drop. For example, if the amount of alumina with 12 μm particle size increases from 5 to 10 wt.%, hardness increases from 47 to 62 BHN and compressive strength rises from 190 to 273 MPa. Nevertheless, erosion rate after 300 m decreases from 0.0447 to 0.0311 mm3/m.