19 research outputs found

    Optimal flank wear in turning of Inconel 625 super-alloy using ceramic tool

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    Rapid tool wear is one of the major machinability aspects of nickel-based super alloys. In this article, the effect of cutting parameters on material removal rate and tool wear of a whisker ceramic insert in turning of Inconel 625 was examined. Optical microscope and scanning electron microscope were applied to measure and study tool wear mechanism. Response surface method was used to develop a mathematical model which confirmed by experimental tests. The statistical analysis done by analysis of variance showed that depth of cut is the most effective factor on the tool wear. Experiments showed that increment of feed rate had an insignificant effect on the progress of flank wear, and it is an important controlling factor when material removal rate is considered as a desired output. Finally, optimized cutting condition is presented in this work

    Wear estimation of ceramic and coated carbide tools in turning of Inconel 625: 3D FE analysis

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    Examination of cutting tool wear by experimental approaches is too costly. The main objective of this work is to develop an accurate 3D finite element model to predict the tool wear of PVD-TiAlN coated carbide and ceramic inserts in turning of Inconel 625. Thus, the cutting tools with complex geometries are modeled. Usui wear rate model is used to estimate wear rate where its constant parameters are achieved based on the cutting tools and workpiece material. The verification tests showed that the predicted values are in good agreement with the experiments. Moreover, among the cutting parameters, the increase of depth of cut were found as the most effective factor on the generation of temperature and stresses on the tool faces

    Optimization of workpiece elastic deflection in machining operations using ant colony system

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    The three principal machining processes are classified as turning, drilling and milling. Other operations falling into miscellaneous categories include shaping, planing, boring, broaching and sawing

    Characterization of various coatings on wear suppression in turning of Inconel 625: A three-dimensional numerical simulation

    No full text
    Applying cutting tool with longer functioning time is a vital issue in machining of the nickel-based super alloys. However, the experimental analysis of this problem is quite expensive. Thus, three-dimensional numerical simulation of tool wear propagation in turning of Inconel 625 super alloy is taken into account, in this study. The cutting insert with complex geometry is modeled by using a reverse engineering method. Based on the cutting tool and workpiece material, Usui wear rate model is exerted to estimate the tool wear rate. In the first section, characterization of TiAlN-coated carbide tool, which is suggested by catalogue, on wear resistance is evaluated and then simulation results are validated with experiments. As a result, increment of depth of cut is the most effective factor on the generation of temperature and stresses on the tool faces resulting in wear rate acceleration. In the second section, different commercial coatings with multicompositions are applied in the simulation to find the best performance against wear. Finally, TiCN coating outperformed other coatings in turning of Inconel 625

    Characterization of various coatings on wear suppression in turning of Inconel 625: a three-dimensional numerical simulation

    No full text
    Applying cutting tool with longer functioning time is a vital issue in machining of the nickel-based super alloys. However, the experimental analysis of this problem is quite expensive. Thus, three-dimensional numerical simulation of tool wear propagation in turning of Inconel 625 super alloy is taken into account, in this study. The cutting insert with complex geometry is modeled by using a reverse engineering method. Based on the cutting tool and workpiece material, Usui wear rate model is exerted to estimate the tool wear rate. In the first section, characterization of TiAlN-coated carbide tool, which is suggested by catalogue, on wear resistance is evaluated and then simulation results are validated with experiments. As a result, increment of depth of cut is the most effective factor on the generation of temperature and stresses on the tool faces resulting in wear rate acceleration. In the second section, different commercial coatings with multicompositions are applied in the simulation to find the best performance against wear. Finally, TiCN coating outperformed other coatings in turning of Inconel 625

    Preparation and characterization of polylactic-co-glycolic acid/insulin nanoparticles encapsulated in methacrylate coated gelatin with sustained release for specific medical applications

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    This study aimed to examine the possibility of using insulin orally with gelatin encapsulation to enhance the usefulness of the drug and increase the lifespan of insulin in the body using polylactic-co-glycolic acid (PLGA) nanoparticles alongside gelatin encapsulation. In this regard, PLGA was synthesized via ring opening polymerization, and PLGA/insulin nanoparticles were prepared by a modified emulsification�diffusion process. The resulting nanoparticles with various amounts of insulin were fully characterized using FTIR, DSC, DLS, zeta potential, SEM, and glucose uptake methods, with results indicating the interaction between the insulin and PLGA. The process efficiency of encapsulation was higher than 92, while the encapsulation efficiency of nanoparticles, based on an insulin content of 20 to 40, was optimized at 93. According to the thermal studies, the PLGA encapsulation increases the thermal stability of the insulin. The morphological studies showed the fine dispersion of insulin in the PLGA matrix, which we further confirmed by the Kjeldahl method. According to the release studies and kinetics, in-vitro degradation, and particle size analysis, the sample loaded with 30 insulin showed optimum overall properties, and thus it was encapsulated with gelatin followed by coating with aqueous methacrylate coating. Release studies at pH values of 3 and 7.4, alongside the Kjeldahl method and standard dissolution test at pH 5.5, and glucose uptake assay tests clearly showed the capsules featured 3�4 h biodegradation resistance at a lower pH along with the sustained release, making these gelatin-encapsulated nanoparticles promising alternatives for oral applications. (Figure presented.). © 2020, © 2020 Informa UK Limited, trading as Taylor & Francis Group
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