Applied Mechanics and Materials Vols. 592-594

Abstract: Productivity is one of the major factors that affect the profit of any industry or any product. In manufacturing industries, the productivity is showing the efficiency of the production unit. It depends on many factors such as technology, machine, method, management etc. In this study, method of manufacturing is considered and analyzed how it affects the productivity. Productivity is normally expressed as the number of units produced / unit time. Sheet metal forming is one of the major manufacturing processes and used for most of the products. The proper design of die is important in sheet metal forming processes. This article discusses how the Combination Die can improve the productivity. For this study, a product “U Clamp” is considered. The Product requires piercing, bending and parting off operations. The Combination Die is designed and fabricated for the product and tested. Data on operation time, material handling time are collected, analyzed and discussed.

Abstract: In this paper, a detailed comparison between dry, wet and gas-cooled turning has been presented based on experimental study. Machining of super duplex stainless steel is considered. Cutting tool considered in this paper is uncoated carbide tool. It was observed that gas cooled machining provides a better machining performance while compared with the dry and the wet machining. Gas cooled machining is particularly needed in case of high speed machining and hard turning. In this study we investigated the chip morphology for various condition of machining and concludes that gas cooled machining is suitable for machining at higher production rate..

Abstract: An experimental study on the fracture toughness of BSCF samples were conducted at room temperature as well as elevated temperatures (upto 800°C). The results showed a typical variation of fracture toughness and fracture stress with temperature. It decreased upto 600°C and then increased to reach a comparatively higher value at 800°C. Without annealing the samples showed comparatively higher fracture toughness because of the presence of compressive residual stress.

Abstract: The corrosion behavior of AZ61 alloyed with 0.5, 1.0, 1.5 and 2.0% Ca were studied by potentiostatic polarization technique in 3.5wt. % NaCl solution and the further effect of corrosion behavior have been studied after aging at different temperature in a controlled environment.The results show that the calcium addition enhances the corrosion resistance.Simultaneously when the alloy is aged at 180°C, the corrosion resistance has improved. This study also reveals the interesting microstructural change that isresponsible for the improved corrosion resistance. Themicrostructural characterization of this alloy was studied using Optical and Scanning Electron Microscopy (SEM).

Abstract: (y) Li_0.5Ni_0.7Zn_0.05Fe₂O₄ + (1-y) Ba_0.5Sr_0.5TiO₃ magnetoelectric composites with y = 0.1, 0.3 and 0.5 were prepared by a conventional standard double sintering ceramic technique. X-ray diffraction analysis confirmed the phase formation of ferrite, ferroelectric and their composites. logρ_dc Vs 1/T graphs reveal that the dc resistivity decreases with increasing temperature exhibiting semiconductor behavior. The plots of logσ_ac Vs logω² are almost linear indicating that the conductivity increases with increase in frequency i.e. conductivity in the composites is due to small poloron hopping. Dielectric constant (έ) and dielectric loss (tan δ) were studied as a function of frequency in the range 100Hz–1MHz which reveal the normal dielectric behavior except the composite with y = 0.1and as a function of temperature at four fixed frequencies (i.e. 100Hz, 1KHz, 10KHz, 100KHz). ME voltage coefficient decreases with increase in ferrite content and was observed to be maximum of about 7.495 mV/cmOe for S₁ i.e. (0.1) Li_0.5Ni_0.7Zn_0.05Fe₂O₄ + (0.9) Ba_0.5Sr_0.5TiO₃ composite.

Abstract: The objective of the present work is to investigate the effects of various WEDM process parameters like pulse on time, pulse off time, corner servo, flushing pressure, wire feed rate, wire tension, spark gap voltage and servo feed on the material removal rate (MRR) & Surface Roughness (SR) and to obtain the optimal settings of machining parameters at which the material removal rate (MRR) is maximum and the Surface Roughness (SR) is minimum in a range. In the present investigation, Inconel 825 specimen is machined by using brass wire as electrode and the response surface methodology (RSM) is for modeling a second-order response surface to estimate the optimum machining condition to produce the best possible response within the experimental constraints.

Abstract: Additive manufacturing (AM) is one the advanced process for building up a component layer by layer, with one layer of material was bonded to the previously laid layer using a 3D design data. In the field of medical science AM is very much useful in the development of Bone Scaffolds. The bone scaffold needs the good level of porosity for the cultivation of cells. In this work, an algorithm for a novel structure with the theme of flexible porosity was introduced. Scaffold models were developed using CATIA V5 for four different porosities. The novel structures made of Poly Amide (PA 2200) material were fabricated using a commercially available Selective Laser Sintering machine (SLS). The differences in scaffold theoretical and experimental porosities were investigated and the percentage of error was discussed.

Abstract: Diamond like carbon (DLC) is a metastable form of amorphous carbon containing fraction of sp² and sp³ bonds. Their mechanical properties depend on the sp³ content as well as on the number and size of graphitic nanoclusters. It is noted that properties change significantly depending on the method of preparation of these films. These properties are also altered by the composition of the films. In view of this, the objective of present work was to deposit hydrogenated DLC films on p-type silicon substrate using inductively coupled plasma enhanced chemical vapor deposition (IC-PECVD) technique with varying bias voltage, bias frequency, gas deposition pressure and gas composition ratio. They play important role in film deposition process and are responsible for change in mechanical properties of the film such as hardness and Young's modulus. Raman spectroscopy was used to study the structural arrangement of carbon atoms. Significant change in the mechanical properties of the film was observed which can be attributed to the change in sp³ and sp² contents in the DLC film. It was observed that the process parameters considerably affect the hardness and Young's modulus of the DLC films. The films of desired mechanical properties can be deposited for various industrial and biomedical applications by maintaining suitable deposition conditions.

Abstract: Co-continuous ceramic composites were fabricated with commercially available SiC porous foams as the ceramic phase and aluminium 6021 alloy as the metallic phase using reactive metal penetration (RMP) process. Microstructure studies, compression test, microhardness test and tests to determine the impact strength were performed on the co-continuous composite. The fabricated composite was lighter and it was found to possess properties comparable to aluminium 6021 alloy.

Abstract: According to the most of the studies dealing with micro grooving, cutting, leading to lower material removal Abrasive jet machining is traditional process. Invention was made to create those needs. A number of investigation or researches were carried out by imminent personality but no detailed information and design has provided about cylindrical vibrating chamber or mixing chamber. This change in shape gives better velocity to abrasive particles and non sticking characteristic gives the better effect of erosion of material on work piece and scattering of particle towards objects. The parameter stand off distance, variable pressure, material removal rate used for this experimental study has also moderate. The work carried out with Alumina nozzle. The abrasive powder feed rate is controlled by the amplitude of mixing chamber. The root mean square value is 0.988 in linear regression model. The estimated standard error is 0.00115 which is very less. The performance of sand gives the similar better model result as given by traditional using different parameter. The taper of cut is higher with this mixing particle and better feed rate.