Advances in Science and Technology Vol. 106

Abstract: Wire-cut electrical discharge machining (WEDM) has emerged as the most important non-traditional machining technique in the recent years due to its exceptional accuracy and capability to produce net near shape components of electrically conductive materials. Ti-6Al-4V alloy is a hard-to-machine material and popularly used in bio-medical, aerospace, automotive, defence applications etc. due to its distinct merits. In this work, Taguchi optimization technique is applied to obtain optimum cutting conditions for material removal rate (MRR) and power consumption (PC) in WEDM of Ti6Al4V alloy. The result showed 16.38% improvement in MRR and 10.36% reduction in PC at the optimal parameter settings compared to initial cutting conditions. ANOVA result established pulse off time and current as highly significant process parameters affecting MRR (I: 56.58%, T_off: 23.57%) and PC (T_off: 43.26%, I: 31.24%). The response surface variation PC and MRR is studied using 3D plots. Surface morphology of machined component using scanning electron microscope images is also discussed.

Abstract: In present work, Aluminium 6061 was reinforced by varying the percentage of sugarcanebagasse ash (SCBA). Al-SCBA composite samples were fabricated by stir casting method. The weartest conducted on the samples using a pin on disc machine under the normal sliding condition. Basedon the testing parameters (Volume fraction ‘V’, Load ‘L’, sliding speed ‘S’) an L27 Orthogonal arraydesign was selected. According to L27 array, the wear & friction test was conducted. variance analysis(ANOVA) was performed to find out the important parameter and contribution in percentage for eachparameter on the composite material. To verify the analysis results with experimented resultconfirmation test was carried out. Further, to find the wear mechanism on the composite sampleselectron microscopy (SEM) test was used.

Abstract: An attempt is made to study the influence of dispersion of Groundnut shell ash (GSA) on the hardness and density of Aluminum Metal Matrix Composite. It is an attempt to use agricultural waste in trying to enhance the mechanical properties of the already existing materials. The work deals with the use of groundnut shell ash, mixed with aluminum using stir casting process. . The composites with varying percentage of groundnut shell ash from 0% to 6% were prepared. The prepared specimens were tested before and after the heat treatment process in terms of its hardness using a Rockwell Hardness Tester. The present work attempts to compare the hardness and density of prepared composites as compared to the alloy. The comparison is carried out before and after the heat treatment process. The results indicate the increasing hardness value and reducing density of composites.

Abstract: The current paper deals about the fabrication of composite material is to combine the desirable attributes of metals and ceramics. Aluminium 6063 used as a base material in combination with the Silicon carbide ,Boron carbide and fly-ash were used as reinforcement material. Our intention is to increased or enhanced properties of pure Aluminium 6063 by addition of Silicon Carbide ,Boron Carbide and fly-ash. The process of fabrication composite material is prepared by using stir casting method. In this paper, addition of Silicon Carbide 1% , Boron Carbide 1% and fly-ash1% with aluminium increasing percentage ratio the mechanical properties of composite material is enhanced, so it is clear that the effect of Silicon Carbide , Boron Carbide and fly-ash were helpful to increasing properties of pure Aluminium by addition. The influence of reinforced ratio of silicon carbide, Boron carbide and fly-ash particles on mechanical behavior was examined. The effect of different weight percentage of silicon carbide, Boron carbide and fly-ash in composite on tensile strength, hardness, microstructure was studied. It was observed that the hardness & tensile strength of the composites increased with increasing reinforcement elements addition in it. The distribution of silicon carbide, Boron carbide and fly-ash particles was uniform in aluminum.

Abstract: Powder mixed electric discharge machining (PMEDM) is a newly developed technology in which EDM is performed by mixing electrically conductive micro or nanoparticles with dielectric fluid. The electrically conductive tiny particles when come at the gap of electrode and work piece, they will begin to create spark by the induction of electrode voltage which enhances the material removal and surface finish of the machined surface. In this paper a brief review has been done on different aspects of powder mixed electric discharge machining. It is observed that the researches are done in three main directions. Firstly, experimental studies are done to show the effect of several input process parameters on responses mainly material removal rate (MRR), surface roughness and tool wear rate. Secondly, the metallurgical characteristics of the machined surface are analyzed to measure the white layer thickness and amount of powder material inclusion onto the surface. The third one is the investigation of thermal characteristics of the tool and work pieces during the machining process. In these three sections of researches, the results of the investigations have been discussed in this review. Keywords: powder mixed electric discharge machining, metallurgical characteristics, nano particles, material removal rate, surface roughness, tool wear rate, white layer thickness, thermal characteristics

Abstract: Most of the sheet metals in general exhibit high an-isotropic plasticity behavior due to the ordered grain orientation that occurred during the rolling process. This results in an uneven deformation yield property that tends to develop ears in case of deep-drawing operation. The deep drawing process is used for the production of cup-shaped articles having applications in automobiles, beverages, home appliances etc. It is essential to know the formability of sheet metals for minimisation of test runs and reducingthe defects. Forming Limit Diagram (FLD) is one of the methods for assessment of formability of sheetmetals. This paper describes various deformation models, yielding and an-isotropic properties and itsdetermination. Through experimental tests, FLD constructed for aluminium alloy AA6111 sheet metalhaving 0.9 mm thickness.

Abstract: Aluminium, magnesium, copper, steels and their alloys are generally used in vast applications like automobile, ship, architecture, aerospace due their properties of high strength to weight ratio, good toughness, ease of recycling and good thermal conductivity. In practical applications, surface treatment is required to meet design requirements and also improves the long-term corrosion resistance and functionality. To enhance surface properties electro deposition, sol-gel, anodization and gas phase deposition are causally used in many industries. For achieving better results, one of the alternative coating has been developed such as black coating to modify the metal substrate properties. These black coating can be prepared by conventional method as well as other methods like micro arc oxidation, plasma electrolytic oxidation and pulse micro arc oxidation techniques. Conventional coloring method shows some disadvantages, for instance, poisonous Cr⁶⁺ ions are formed while preparing black oxide coating by conversion of chromium. To avoid such disadvantages, micro arc oxidation, plasma electrolytic oxidation and pulse micro arc oxidation are developed. Based on these techniques, surface properties like long-term corrosion resistance, wear resistance, biocompatibility and decoration are enhanced. Black coatings have high hardness, good bonding with metal substrate, light aging resistance and higher thickness of coating due to strongest absorption ability. This paper mainly focusses the generation of black oxide coating on steel, aluminum, magnesium and copper.

Abstract: Calcium Bismuth Titanate (CaBi₄Ti₄O₁₅) ceramics were prepared by conventional solid-state reaction method. X-ray diffraction patterns confirms the orthorhombic structure of CaBi₄Ti₄O₁₅ and the lattice parameters were also determined. Bulk densities of the sintered ceramics were measured by the Archimedes method with xylene as the liquid media and found to be 97~98% of X-ray density. The surface morphology of CaBi₄Ti₄O₁₅ is studied by Scanning Electron Microscope (SEM) attached with energy dispersive X-ray spectroscopy (EDS) inorder to determine the grain size as well as the chemical composition of CaBi₄Ti₄O₁₅. The dielectric constant (k) and dielectric tangent loss (tan δ) of CaBi₄Ti₄O₁₅ as a function of temperature were measured in the frequency range of 100 Hz-100 KHz. The dielectric constant, dielectric loss and ac conductivity of CaBi₄Ti₄O₁₅ increases gradually with an increase in the temperature from 303 to 573 K. The ac conductivity of the prepared sample reveals that the conduction mechanism is electronic hoping

Abstract: The heat generation and subsequent temperature rise in the cutting zone due to plastic deformation and friction at tool-chip-workpiece interface are critical parameters that have a significant impact on tool wear, tool life and surface integrity. This paper aimed to analyse the effect of cutting parameters such as, cutting speed, feed and depth of cut on the cutting temperature in turning of hardened AISI 52100 alloy steel of 58 HRC using multilayer coated carbide cutting tool insert under high velocity pulsing jet minimal cutting fluid application (MCFA) environment. Response surface methodology based central composite design (CCD) was used to investigate and optimize the cutting parameters on cutting temperature response. The quadratic regression model in terms of cutting speed, feed and depth of cut for cutting temperature was developed. The diagnostic and confirmatory tests were carried out to check its validity. The implication of the process parameters and their interactions were tested using analysis of variance (ANOVA). The results showed that the cutting speed and feed were the main significant parameters affecting the cutting temperature, while depth of cut and quadratic term of cutting speed had a moderate effect. The predictive model developed indicates the 99% desirability level in turning of AISI 52100 hardened steel under the MCFA environment. The predicted values of cutting temperature response are in close agreement with the experimental results.