Volume 15, Issue 4 -

The paper focuses on the effect of various process parameters like spindle speed, feed, depth of cut, nose radius and machining condition on the Tool tip temperature and surface roughness in step turning process is investigated by using Factorial Technique. Five factors- Two levels are used and total 32 experiments are performed. The coefficients are calculated by using regression analysis and the model is constructed. The adequacy of the developed model is checked using Analysis of Variance (ANOVA) technique. By using the mathematical model the main and interaction effect of various process parameters on tool tip temperature and surface roughness are studied.

In recent days, the silicon carbide particulate reinforced aluminium metal matrix composites are most promising material in various engineering applications due to their strength to weight ratio, wear resistance and thermal resistance over the non-reinforced alloys. However, these materials are very difficult to cut by conventional machining methods due to the presence of silicon carbide particles. To overcome this limitation, the wire electrical discharge machining (WEDM) is employed to machine these composites. The aim of this study is to optimize the process parameters in wire electrical discharge machining (WEDM) of Al6061/SiCp composite using AHP-TOPSIS method. Al 6061/2% SiCp/3 µm particulate metal matrix composite is fabricated by using stir casting method and the uniformity of particle distribution was analyzed by SEM. Taguchi L 18 orthogonal array is designed by considering various process parameters viz. Wire Type (WT), Pulse ON Time (T ON), Pulse OFF Time (T OFF), Wire Feed rate (WF) and Sensitivity (S) for conducting WEDM experiments. The obtained experimental results were analyzed and the results revealed that Sensitivity (S) is the prevailing factor on the response characteristics of WEDM followed by pulse ON time (T ON), wire feed rate (WF), Wire Type (WT) and pulse OFF time (T OFF).

The results of an experimental investigation of the mechanical properties of boron carbide (B 4 C) and molybdenum disulphide (MoS 2 ) reinforced aluminium alloy (AA2024) hybrid composite samples, processed by stir casting process are reported in this paper. Based on the previous studies, it was concluded that for 4% of weight of the B 4 C powders reinforced in AA2024 metal matrix have better mechanical properties like tensile strength and hardness than the base alloy. Also the 4% of MoS 2 reinforced in AA2024 metal matrix exhibited good mechanical properties than the matrix metal. Hence an attempt has been made to further improve the properties of the composite using both B 4 C and MoS 2 as reinforcement particles in the AA2024 matrix. in the present study hybrid composite specimen were developed varying the weight% of B 4 C and MoS 2 , viz., 1%+3%, 2%+2%, 3%+1% B 4 C and MoS 2 respectively in the AA2024 matrix. The prepared samples were subjected to a series of mechanical tests like tensile and hardness tests. Further, SEM & XRD analyses were performed on the prepared samples to study the microstructure and to ensure the proper dispersion of the reinforced particles in the metal matrix.

Experimental and numerical investigations were carried out on synthesis of Si from SiO 2 using thermal plasma reactor. Temperature profile and gas flow distribution in the thermal plasma reactor were developed by the computational fluid dynamics (CFD) with ANSYS Fluent. The predicted temperatures are in good agreement with the experimentally measured temperatures in the reactor. Experiments were carried out at power 22.5 kw, SiO 2 feed rate of 4 g/min, molar ratio of SiO 2 to methane varied from 1 to 4:1. Samples from different sections of the reactor are collected and characterized using SEM and XRD. Effect of molar ratio of SiO 2 to methane on the yield of Si showed that increase in molar ratio increased the Si yield. Based on the analysis of experimental and numerical results, a mechanism of thermal plasma synthesis of Si from SiO 2 is proposed.