Mechanical Engineering

This paper presents the characterization of solid state sintering schedule for near-net shaping of warm formed metal powder compacts. Iron ASC 100.29 powder was used as main powder constituent during this investigation.  The feedstock was prepared by mechanically mixed iron powder with 0.4 wt% zinc stearate as admixed lubricant. The powder mass was then formed as solid cylinder at 180ºC.  The defect-free green compacts were sintered in an argon gas fired furnace at different sintering schedule. The sintered products were characterized through dimensional measurement, and mechanical testing. The results revealed that sintering schedule plays an important role in manufacturing near-net shape yet high strength components.

This paper reports the effects of sintering schedule to the mechanical properties and microstructure of warm formed powder compacts. Iron powder ASC 100.29 was used as main powder constituent whereas zinc stearate was used as lubricant. The premixed powder mass was compacted at 180ºC by applying 130 kN axial loading and sintered in an inert gas fired sintering furnace at different sintering schedule. The sintered samples were characterized to evaluate their mechanical properties and microstructures. The effect of sintering schedule was studied in terms of mechanical properties, focusing in particular on the relative density, flexural strength and hardness. The microstructure analysis was performed to determine the pore shape, size and distribution. The results revealed that the mechanical properties and microstructures of sintered products were affected by the sintering temperature, holding time as well as the heating/cooling rate.

Classical reliability based design procedures require tedious calculations and time consuming. The goal of reliability of mechanical component adequately performs its intended function when operating under specified environmental conditions. Mechanical component design by safety factors using nominal values without considering uncertainties may lead to designs that are unsafe, or too conservative and thus not efficient. Design of a hollow shaft is one of complex and time consuming design procedure. This paper presents development of mathematical models to predict the outer diameter of a typical hollow shaft. This paper presents unique method to investigate engineering problem, its analysis, mathematical modeling and optimization with the help of RSM-response surface methodology and design of experiments (DOE). Response surface methodology, which is a statistical approach of design of experiments, is being applied with combined probabilistic design to optimize the design responses in the case of simultaneous variations of its design parameters. The technique is proved to be efficient and general purpose modeling a variety of components.

Tremendous heat energy waste in steel plant through ladle, but nobody think over this issue. A Heat Energy Solidification process are simulated for a continuous casting machine and the constructive shape of the liquid pool is predicted considering at different conditions. Heat energy and Solidification model is described for the C.C. of Steel Slabs. The Model has been established on the basis of the technical conditions of the slab caster in the C.C.

The Present research has focused on mechanical behaviour of aluminium oxide reinforced aluminium metal matrix composites. Aluminium metal matrix composites are fabricated using stir casting process by varying the reinforcement percentage volumes between 0 and 10, with 30 ?m particles size. To study the mechanical behaviour through the effect of weight percentage of aluminium oxide, the fabricated specimens are tested for the mechanical and physical properties such as tensile strength, hardness and density and these values are compared with theoretical values which are obtained through the rule of mixtures. The mechanical properties of the composites are found to be greatly influenced with increasing the percentage volume of the reinforcement. Also it was observed that the experimental values of mechanical behaviour of AMMCs are nearer to the theoretical values.

V-Trough solar simulator (VTSS) was designed and constructed at Measurements lab of Annamalai University and its performance was analyzed on indoor test facility. Integrating the heat pipe with V-Trough absorber plate can improve the system performance. VTSS system uses three different heat pipes such as circular, semicircular and Elliptical of same length 900 mm and diameter of 18 mm, 22 mm, 24 mm respectively. The experiment had been conducted by changing the heat pipes of the collector (VTSS). The output responses such as heat output, thermal resistance and overall efficiency has been analyzed with respect to each heat pipe experimentally by using commercial Design of Expert version DX 9 software by using Box- Behnken design of Response Surface Method (RSM). Contour diagram shows the factors effecting and thermal behaviour of the heat output, thermal resistance and overall efficiency has been shown. From the mathematical results and RSM optimization it is concluded that experimental setup integrated with circular heat pipe gives higher heat output and overall efficiency with less thermal resistance.

The cutting forces required for machining of a material are important factors in production design that need to be evaluated carefully for newly developed materials. The cutting forces directly influence the power requirement of the machine tool, tool deflection and tool wear, among other things. In this study a computational model will be developed for prediction of cutting forces in end milling of metal matrix composites. Modeling of cutting forces in milling involves evaluation of chip load, instantaneous shear angle, strain rate and temperature dependent shear stress. The computational model will be validated against experimental data from measurements of cutting forces during end milling of composites under different conditions. The validated model will then be used to conduct a parametric study on the influence of feed rate (f), depth of cutting (a), cutting speed (v), and other cutting parameters on the cutting forces generated during the end milling of composites.

In the present work the effect of heat treatment on wear behavior of AISI310, AISI253ma and AISI410 Silicon steels are investigated. The chosen materials were heat treated at 8500C and kept at this temperature for a soaking period of 60 minutes, cooled by quenching in air until the room temperature is attained. As-cast materials were also taken for tests for comparison. The wear tests were carried out on above three materials with three parameters viz., velocity, load & time by keeping two of the parameters as constant and varying the other one in each test.

Adhesive joints are used in a wide range of industrial applications due to their advantages over other joints. The crack propagation analysis in an adhesive joint is very important for its sustained performance. The Cohesive zone model (CZM) is found to be effective in this area due to its advantage over traditional methods. An overview of the CZM, usage with Finite Element Analysis (FEA), comparison with other methods, and implementation by back face strain (BFS) technique are reviewed in a proportional manner

The cohesive zone model (CZM) can be regarded as a computational model which provides valuable insights in the prediction of crack initiation and propagation. The concept behind this model considers the process of fracture as a gradual phenomenon in which separation takes place between two adjacent virtual surfaces across an extended crack tip. The role of the CZM in analyzing the crack propagation in different materials and variations in the traction separation law(TSL) are covered in a detailed manner in this paper.