Microstructural evolution in hot compressed TiHy 600 titanium alloy

TiHy 600 alloy is a near alpha titanium alloy, widely used for gas turbine engine applications such as disc and blades for high pressure compressors. One drawback of this alloy is that it is susceptible to cold dwell fatigue, which is due to the presence of micro-textured zones. Thus, appropriate processing parameters (i.e. temperature, strain and strain rate) are required to reduce the size of the micro-textured region. In order to find out the optimized processing parameters, hot compression tests were performed up to 50% engineering strain at temperatures range of 900oC-1050oC and strain rate range of 10-3 to 101 s-1 using thermo-mechanical simulator (Gleeble 3800®). Flow behavior characteristics were studied from the data obtained during hot compression and processing map was developed at true strain of 0.6 using Dynamic Materials Modeling (DMM) approach. Microstructural examination of deformed TiHy 600 titanium alloy were carried out at a particular strain rate of 10-3 s-1 and temperatures of 900oC, 950oC, 975oC, 1000oC and 1050oC. Microstructural examination consists of orientation image mapping along compression direction using electron backscatter diffraction. Hot compression mostly resulted into new dynamic recrystallized (DRX) alpha grains at 900oC, mixture of deformed large alpha grains containing subgrain boundaries and transformed beta phase consisting of secondary alpha laths at 950oC and 975oC and alpha laths transformed from deformed beta grains at 1000oC and 1050oC

Effect of Ti reinforcement on the physical and mechanical properties of AZ91/Ti composites

602-607Magnesium-metal matrix composites reinforced with ceramic materials (TiO2, SiC, B4C, Al2O3) have better mechanical strength as compared to pure magnesium but their ductility is very low. On the other hand, the Mg-based composites reinforced with carbonaceous (carbon nanotubes, graphite, graphene, etc.) reinforcements have better wear resistance; however, there are chances of agglomeration of reinforcement. To overcome the limitations mentioned above; the Mg based composites reinforced with metallic reinforcements (Ti) have prepared in the present work. The physical and mechanical properties of prepared Mg/Ti composites have diagnosed experimentally. The density (green and sintered), hardness, compressive stress, and ductility have increased with the addition of Ti to the Mg matrix. Reason for increase in the density and other mechanical properties after the addition of Ti to the Mg matrix is the increased compressibility, reduced porosity and proper mechanical bonding of Mg-Ti. The maximum hardness (47.5 BHN) and ultimate compressive strength (187 MPa) has obtained for Mg + 6% Ti composite

Evaluation of nephroprotective and nephrocurative activity of Aegle marmelos on albino rats using experimental model

Background: Renal diseases are common now days because of multiple nephrotoxic drugs use like aminoglycosides, analgesic etc. Many diseases like Diabetes and Hypertension also contributing to renal diseases. One of the mechanisms for nephrotoxicity is production of free radicals. The phytochemicals obtained from some plants are claimed to be useful in prevention of nephrotoxicity. One of the good sources of these phytochemicals is leaves of Aegle marmelos (Bael) which has antioxidant property that can be useful in nephroprotection. Hence this study was designed to investigate the nephroprotective as well as nephrocurative potential of Aegle marmelos.Methods: Study was done on albino rats at LLRM Medical College as per CPCSEA guidelines after obtaining permission from IAEC. Nephrotoxicity was induced using injection gentamicin(40mg/kg). The nephroprotective and nephrocurative effect was quantified using serum markers (BUN, Serum creatinine) and histopathological changes. Statistical analysis was done using ANOVA followed by post hoc dunnet’s test.Results: When compared with gentamicin induced nephrotoxicity, rats those who received aqueous extract of Aegle marmelos leaves showed significant (p<.001) reduction in nephrotoxicity.Conclusions: It can be concluded from this study that leaves of Aegle marmelos possess siginificant nephroprotective activity.

Evaluation of nephroprotective and nephrocurative activity of Solanum nigrum on gentamicin induced nephrotoxicity in experimental rats

Background: Aminoglycoside antibiotics are most commonly used drugs for the prevention and treatment of gram negative infections. Nephrotoxicity is the main side effect that restricts its long duration use. Modern medicines to treat nephrotoxicity are costly and also not vary effective. Solanum nigrum fruits, having potent antioxidant property can be used for nephroprotection as well as nephrocure.Methods: The study was carried out in two phases. Nephroprotective phase, 54 rats were randomized in 3 groups named G10, G20 & G30 according to 10, 20 & 30 days of treatment. Each group was randomized in three subgroups i.e. control C group [received normal saline (2 ml/100 gm/day) daily for test duration], GT group [received normal saline (2 ml/100 gm/day) daily for test duration & intra-peritoneal gentamicin (40mg/kg) for last five days] & SNT group [received orally S.nigrum (200 mg/kg/day) daily for the test duration and intra-peritoneal gentamicin (40 mg/kg) for last five days]. Rats were sacrificed 24 hours after the last dose of gentamicin (on 11th, 21st and 31st day). In nephrocurative phase, 72 rats were randomised in two groups of 36 rats each. Group-1 received intra-peritoneal gentamicin (40 mg/dl) for five days. Group-2 received intra-peritoneal gentamicin (40 mg/dl) for five days and then S.nigrum (200 mg/kg/day) orally till the rats are sacrificed. Six rats from each group were sacrificed on 3rd, 5th, 7th, 10th, 12th and 14th day after administration of last dose of gentamicin. Blood sample were taken for evaluation of BUN and serum creatinine.Results: There was significant decrease in BUN and serum creatinine values as compared to GT group in all test duration in phase-1. In phase two there was no significant difference of these markers in two groups.Conclusions: S.nigrum fruits extract provide nephroprotection against gentamicin induced nephrotoxicity

Manufacturing and Evaluation of Mechanical Properties for Rice Husk ParticleBoard Using IoT

In recent times, different types of particleboards are being preferred in the construction of houses, partitions, furnitureetc. The production of such materials can be manufactured using rice husk, which has been obtained as waste produced inrice millers. Adhesive such as formaldehyde, when exposed to fire, causes toxic flames which are fatal in nature. The basiccondition for production of particleboards is to check the temperature and humidity content in the rice husk which has beendone by using DHT 11 sensors i.e., application of Internet of Thing (IoT) erected method. This identification helps infinding the suitable temperature through which bio-based adhesives have been prepared. In present study, two differenttypes of bio-adhesives namely tamarind with formalin and tamarind with boric acid has been used in manufacturing process.The application of IoT erected method follows a complex preparation method but will partially fulfil the job and reduceshuman involvement. Finally, when the proper temperature and moisture level has been measured, the preparation becomeseasy. After manufacturing the particleboard, the strength has been tested by a three-point bend test and have been comparedwith commercially available boards with formaldehyde base adhesive

Optimization on Manufacturing Processes at Indian Industries Using TOPSIS

Evaluation and optimization of multi-criteria with multiple alternatives have been essential activities for decision-making process. TOPSIS (Technique for order of preference by similarity to ideal solution), a multi-criteria decision-making (MCDM) technique, has been adopted in the past for research &amp; decision-making and ranking of alternatives by optimizing input parameters to get the maximum overall output from the system. This study aims to explore the context, reasons, and particular advantages of using TOPSIS in the materials science and engineering field for realizing goals of competitive supply chains (SCs). This study has reviewed and analyzed research papers from the approach of systematic review of the literature. This study has presented a conceptual framework to emphasize the antecedents and consequences of using the TOPSIS methodology for output optimization in the materials science and engineering industry that can improve the competitiveness of SCs. This study found that TOPSIS based methodologies have been used in eleven types of industries in India, indicating the prowess of TOPSIS methodology. The results of TOPSIS have compared very well with other MCDM methods that are relatively more difficult and cumbersome. This study will help the engineers, practitioners, academicians, researchers, and SC managers with the application approach of TOPSIS for output optimization in various fields

Depth Profiles of Residual Stresses in Inconel 718Machined with Uncoated and Coated Tools

567-573Inconel 718 is one of the super-alloy materials, belonging to nickel-chromium alloy family, which has major applications in aerospace sector such as engine parts and turbine components. Durability of these components during engineering performance is affected by residual stresses induced in them in the course of their manufacturing processes. The concept of the present paper is to provide an insight view of induced residual stresses in Inconel 718 work piece, when machined with coated (TiN) and uncoated tools at optimum conditions. For this purpose, turning experiments have been conducted on IN718 material through statistical approach using L9 orthogonal array. Taguchi optimization method is exercised with the emphasis on minimizing the cutting forces resulted during machining. The residual stresses generated in the work piece at the optimum conditions employed for both the tools have been evaluated using XRD method. Conditions such as cutting speed of 60 m/min, feed at 0.068 mm/rev and depth-of-cut of 0.10 mm have been optimized for achieving minimum cutting forces during machining of IN 718 using both coated and uncoated tools. However, tensile stresses on the initial surface layer and compressive stresses in the sub-surface layers are found higher in the work piece material machined with uncoated tool. Surface roughness and temperature developed on the surface of the machined bar are higher in case of uncoated tool than those with coated tool

Electrical Discharge Coating a Potential Surface Engineering Technique: A State of the Art

Electrical discharge coating (EDC) process is used to deposit material on workpiece surface from sacrificial or green compact tool electrode in an electrical discharge machine. The paper presents the mechanism of EDC using green compact electrode and powder mixed dielectric methods. The tool electrode material, electrode size, process parameters, and type of dielectrics can directly affect the surface integrity of workpiece. Here, a process map of EDC as a function of process parameters, its classification, advantages, and applications for a wide range of engineering materials offers a proper template for the evaluation of coating phenomena. This study shows that EDC is an economic process as compared to other costlier techniques. Additionally, the effect of various EDM and EDC parameters on surface integrity and tribological behavior of deposited coatings is studied with their pros and cons. Finally, the current research trends of EDC and its challenges are elaborated.info:eu-repo/semantics/publishedVersio

Experimental and Finite Element Studies of Stretch Forming Process for ASS 316L at Elevated Temperature

Austenitic stainless steel 316 L grade is a material having extraordinary mechanical properties, low cost and easily available. This is the reason it was used in various industrial and nuclear applications. In the present work, ASS 316L nakazima specimens are stretched under hot forming conditions (750°C, 825°C and 900°C) at a constant strain rate (0.1s-1) along with three different orientations. These six types of nakazima specimens were used to know the formability behaviour of the material with the help of forming limit diagrams (FLD) obtained by the stretch forming process. A smaller change in Punch load and an increase in displacement were observed, which indicates the formability improvement of ASS 316L sheet metal with the increase in temperature. In addition, ABAQUS 6.13 computer code was applied for the prediction of formability from 750°C to 900°C.To improve the accuracy of the simulation, a number of integration points were accrued within the thickness direction, limiting dome height (LDH).The ductile fracture was observed from SEM images for all the temperatures. A close agreement was found between experimental and simulated results

Understanding the Mechanism of Abrasive-Based Finishing Processes Using Mathematical Modeling and Numerical Simulation

Recent advances in technology and refinement of available computational resources paved the way for the extensive use of computers to model and simulate complex real-world problems difficult to solve analytically. The appeal of simulations lies in the ability to predict the significance of a change to the system under study. The simulated results can be of great benefit in predicting various behaviors, such as the wind pattern in a particular region, the ability of a material to withstand a dynamic load, or even the behavior of a workpiece under a particular type of machining. This paper deals with the mathematical modeling and simulation techniques used in abrasive-based machining processes such as abrasive flow machining (AFM), magnetic-based finishing processes, i.e., magnetic abrasive finishing (MAF) process, magnetorheological finishing (MRF) process, and ball-end type magnetorheological finishing process (BEMRF). The paper also aims to highlight the advances and obstacles associated with these techniques and their applications in flow machining. This study contributes the better understanding by examining the available modeling and simulation techniques such as Molecular Dynamic Simulation (MDS), Computational Fluid Dynamics (CFD), Finite Element Method (FEM), Discrete Element Method (DEM), Multivariable Regression Analysis (MVRA), Artificial Neural Network (ANN), Response Surface Analysis (RSA), Stochastic Modeling and Simulation by Data Dependent System (DDS). Among these methods, CFD and FEM can be performed with the available commercial software, while DEM and MDS performed using the computer programming-based platform, i.e., "LAMMPS Molecular Dynamics Simulator," or C, C++, or Python programming, and these methods seem more promising techniques for modeling and simulation of loose abrasive-based machining processes. The other four methods (MVRA, ANN, RSA, and DDS) are experimental and based on statistical approaches that can be used for mathematical modeling of loose abrasive-based machining processes. Additionally, it suggests areas for further investigation and offers a priceless bibliography of earlier studies on the modeling and simulation techniques for abrasive-based machining processes. Researchers studying mathematical modeling of various micro- and nanofinishing techniques for different applications may find this review article to be of great help