Composite Materials
Arumugam Mahamani; S Jawahar; J P Davim
Abstract
In-situ composites are gained the attention of worldwide researchers in the interest of its greater mechanical properties at the lower reinforcement ratio. Controlling the surface quality of the component is a paramount task in grinding process in order to withstand the creep and fatigue load at service ...
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In-situ composites are gained the attention of worldwide researchers in the interest of its greater mechanical properties at the lower reinforcement ratio. Controlling the surface quality of the component is a paramount task in grinding process in order to withstand the creep and fatigue load at service conditions. The current effort is intended to examine the mechanism of surface generation in grinding of AA6061-TiB2/ZrB2 in-situ composites under different reinforcement ratio, grinding parameters and wheel materials. The analysis of results indicates that the grinding of unreinforced alloy is complicated than the composites. Diamond wheel yields superior performance by generating lesser surface roughness and subsurface hardness at all grinding conditions. Among the various grinding parameters, grinding speed and grinding depth are more sensitive than other parameters. This experimental investigation helps to control the surface roughness and subsurface at various grinding conditions. Understanding of surface generation mechanism in grinding of in-situ composites helps to employ the grinding process for economic machining rate without negotiating the surface quality.
Machining
Pawan Kumar; Meenu Gupta; Vineet Kunar
Abstract
With the increased diversity of the customer demand and complexity of the product Inconel 825 is widely used to meet the actual needs especially in aerospace industry. It is difficult-to-cut material because of its high toughness and hardness. The present research attempts to optimize the process parameters ...
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With the increased diversity of the customer demand and complexity of the product Inconel 825 is widely used to meet the actual needs especially in aerospace industry. It is difficult-to-cut material because of its high toughness and hardness. The present research attempts to optimize the process parameters of wire electric discharge machining (WEDM) during cutting operation of Inconel 825. WEDM characteristics such as pulse-on time (Ton), pulse-off time (Toff), spark gap voltage (SV), peak current (IP),wire tension (WT), wire feed (WF) are taken into consideration. Performance was measured in terms of material removal rate (MRR), surface roughness (SR) and wire wear ratio (WWR). Central composite design (CCD) of response surface methodology (RSM) at α value of ± 2 was employed to establish the mathematical model between process parameters and performance measures. Multi-objective particle swarm optimization (MOPSO) algorithm has been used to find the Pareto optimal solutions. It uses the concept of dominance to find the non dominated set in the entire population and crowding distance approach to find best Pareto optimal solutions with a good diversity of objectives. The confirmation experiments of MOPSO algorithm shows the significant improvement in MRR (27.934 to 31.687 mm2/min), SR (2.689 to 2.448μm) and WWR (0.027 to 0.030). SEM micrograph studies showed the number of cracks, pockmarks, craters, and pulled out material on the workpiece and wire electrode surface. Energy Dispersive X-ray analysis is performed to investigate the presence of elements on the work surface other than base material.
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