Piece Surface Research Articles

Strong classification system for wear identification on milling processes using computer vision and ensemble learning

Metallic pieces are typically machined by continuous tool passes, which usually causes regular patterns in the form of straight edges in the surface of the pieces. An irregular pattern on the surface of the piece implies a decrease of the quality of the machined piece. In this paper, we propose an acquisition system and a machine-vision based method to describe the texture of the inner and outer surfaces of machined pieces with cylindrical holes. In order to capture images of the hole surface, we used a microscope camera connected to a rigid industrial boroscope. Considering the extracted texture descriptors, a significant correlation is shown. Consequently, the feature vector is reduced and then classified by several algorithms using an exhaustive grid search strategy with 10-fold cross validation. Best results are achieved with the Extremely Randomized Trees classifier with a mean test score on the hold out set of 92.98%, what improves previous research and meets the requirements of the field.

Safety of Concentrated Bioshell Calcium Oxide Water Application for Surface and Skin Disinfections against Pathogenic Microbes.

Immediately post-production, commercially available bioshell calcium oxide (BiSCaO) water is colorless, transparent, and strongly alkaline (pH 12.8), and is known to possess deodorizing properties and broad microbicidal activity. However, BiSCaO Water may represent a serious safety risk to the living body, given the strong alkalinity. This study aimed to investigate the safety of BiSCaO Water for use as an antiseptic/disinfectant despite concerns regarding its high alkalinity. The change over time in pH of BiSCaO Water was measured during air contact (stirring BiSCaO Water in ambient air). When sprayed on metal, plastic, wood piece, paper, and skin surfaces, the pH of BiSCaO Water decreased rapidly, providing a white powder coating upon drying. Scanning electron microscopy images, energy dispersive X-ray elemental mapping, and X-ray diffractograms showed that the dried powder residues of BiSCaO Water were composed primarily of calcium carbonate. These results suggested that BiSCaO Water is a potent reagent that may overcome the obstacles of being strongly alkaline, making this material appropriate for use in disinfection against pathogenic microbes.

An experimental study on enhancement of cutting tool properties by tool hardening and hard coating method

The cutting apparatus is a prime significant instrument required in metal expulsion activities for delivering the parts. It produces part as well as keeps up the dimensional exactnesses, geometrical tolerances and wanted surface finish of the machined part. In order to meet all the specific parameters like wear, surface finish, and hardness, etc., there are various cutting-edge technologies are evolving now a days for the betterment in achieving quality. In this paper, experimental study is carried out to identify high reliable tools with hard coated cutting tools (mix and addition of cutting material and hard coatings) where is necessary to regularize the coating and hardening procedures to test new tools at normal working conditions. Here the machining performance of cutting tool in machining SS140 material, uncoated, stellite coated, solidified hardened tools were inspected and their wear, handling time and resultant machined piece surface completion were analyzed.

Modeling and analysis of developed Thermal additive Centrifugal Abrasive Flow Machining process

In the present scenario due to manufacturing revolution there is a huge demand of mechanical components having high surface finish and a long life cycle. Demand of high surface finish, leads to development of new techniques for nano finishing of intricate shapes, such as Abrasive flow machining (AFM) and hybrid forms of it. During the abrasive flow finishing process, abrasive particles impart a huge impact force on the work piece surface to increase surface finish. This research paper discuss about a newly developed thermal additive centrifugal abrasive flow machining process (TACAFM) and also develops a mathematical model for the material removal of developed process at a given thermal energy pulse. Novelty of TACAFM process reduced the force applied by the abrasive particles and also decreased the loss of energy. In this hybrid process abrasive particles can easily remove the molten/ semi molten material from the work surface under thermal spark mechanism. The experimental results showed material removal in case of TACAFM process is almost double in comparison of conventional AFM process. The oxide layers and molten material on work surface was also observed from SEM images, which clearly indicated the domination of thermal effect over AFM. Also the parameters were optimized for the residual stress in case of TACAFM process and optimum residual stress was found as −152.21 MPa, which shows compressive stress developed on the surface due to the thermal effect. The experimental result showed current is the most significant parameter in TACAFM process and its contribution was found as 91.8%.

Optimization of machining parameters of aluminum alloy 6026-T9 under MQL-assisted turning process

The lower lead time and increasing demand for good quality parts require the industries to produce the parts manufactured sustainably with higher precision, improved productivity, and low cost using new techniques. Minimum quantity lubricant (MQL) is one of these techniques, which is economical and eco-friendly. This paper deals with the analysis and multi-response optimization of cutting process parameters of Aluminum alloy 6026-T9 in MQL and dry conditions using an integrated approach of composite desirability function and criteria importance through inter-criteria (CRITIC). The cutting parameters considered for the study are cutting speed, feed rate, depth of cut, and positive rank angle, while the responses are surface roughness profile (Ra, Rq, Rz), tool life and material removal rate. The type of insert used was a tungsten carbide, while the coolant was minimum quantity lubricant (MQL) vegetable oil (olive oil) performed at 150mL/hr. Taguchi orthogonal array (L16) using sixteen experimental runs are designed for machining. Based on analysis of variance (ANOVA) it is identified that the most significant cutting process parameters for surface roughness profile (Ra, Rq, Rz) under both dry and MQL conditions are the feed rate, while for the tool life are cutting speed and feed rate and for material removal rate is cutting speed followed by depth of cut and feed rate. Under dry conditions the optimized levels obtained are cutting speed of 500m/min, the feed rate of 0.3mm/rev, depth of cut of 2mm, and positive rake angle of 15°. However for MQL condition are cutting speed of 500m/min, the feed rate of 0.4mm/rev, depth of cut of 2mm, and positive rake angle of 15°. Finally, the machined worked piece surface and inserts are morphologically characterized at different cutting parameters using scanning electron microscopy (SEM) and Energy Dispersive X-Ray Analysis (EDX).

Gamma radiation effect on the midgut bacteria of Plodia interpunctella and its role in organic wastes biodegradation

This paper focuses on some factors that affect the gut bacterial communities of Plodia interpunctella and their role in the removal of plastic polymer concentrations to make a clean environment. Counting of midgut bacteria from P. interpunctella reared on different diets exhibited that wheat bran gave a significantly higher number of colonies than other diets (84 × 102 CFU/gut). Histological midgut studies on control fully grown larvae showed different shapes of epithelial cells, elongated or pyramidal, and few numbers of oval regenerative cells. Various secretions are released from the apical margin of the cells. The peritrophic membrane cannot be detected and large numbers of bacteria occupied the midgut lumen. While, irradiated larvae with 250 Gy revealed sever damaged midgut cells, some cells appeared swollen and the others fused as heterogeneous mass. Besides, ruptured of peritrophic membrane and very reduction in the bacterial population were appeared in the lumen. In this respect, two bacterial isolates were isolated from the midgut larvae and identified by 16S rRNA gene sequencing with accession number NR 146667.2 and NR 112686.1, as Enterobacter tabaci strain YIM Hb-3(B1) and Bacillus subtilis subsp. Spizizenii strain NBRC 101239(B2), respectively. Scanning electron microscopy analysis revealed alterations in the polyethylene during 60 days of incubation. Two bacterial strains showed damaging effects on plastic including cavities and pits on the surface of plastic pieces increased with the time of treatment. Moreover, the formation of carbonyl groups was verified using a fourier transform infrared imaging microscope.

Generation of Biocompatible Titanium Alloy Surfaces Including Calcium and Phosphorus Elements by Laser-Induced Mist Spraying Wet Treatment

Titanium alloys are widely used for the hard tissue substitute implants. However, it is necessary to improve interfacial biocompatibility to reduce adhesion period. For improvement of biocompatibility of Ti-6Al-4V ELI alloys, texture and chemical composition on contact part with biological tissue play very important roles. In this research, micro texture was generated on the Ti-6Al-4V ELI alloy surfaces utilizing laser irradiation, in order to improve biocompatibility. The biocompatibility was evaluated by osteoblast cell culture assays. The results indicated the surface having micro texture improve biocompatibility as compared with untreated surface. This was considered in order the fact that the formed modified surface had hydrophilicity, thereby improving the cell compatibility, and the cell adhesion due to the complicated shape. In addition, mist of glycerophosphoric acid calcium aqueous solution was applied on the laser irradiated area. As result, micro texture including Ca and P elements was generated on the Ti-6Al-4V ELI alloy surfaces. When laser was irradiated, glycerophosphoric acid calcium aqueous solution was applied as mist flowed on the test pieces as droplet. The velocity of droplet fluid was relatively fast, so that laser irradiation was unhindered access to the surface of test pieces and the treatment was stable. In order to estimate biocompatibility, culture assays using osteoblast cells were conducted on the treated surface having micro texture including Ca and P elements. As results, it was clearly that biocompatibility of the specimen treated by laser with glycerophosphoric acid calcium aqueous solution mist more improved than either untreated specimen or treated specimen soaked in glycerophosphoric acid calcium aqueous solution.

Tratamiento de erosión dental con coronas preformadas de acero. Reporte de caso

La erosión dental es la pérdida crónica e indolora del tejido duro del diente que se produce por agentes ácidos o quelantes sin intervención bacteriana. El propósito de este reporte de caso es describir la rehabilitación oral integral de un paciente con erosión dental debido a reflujo gastroesofágico. El presente reporte describe el caso de una paciente en la cual se observó caries dental en caras oclusales de piezas 55 y 65; y desgaste de caras oclusales con compromiso de dentina en piezas 64, 74, 75, 84 y 85. Las piezas con caries fueron restauradas con resina compuesta y las piezas con desgaste oclusal fueron restauradas con coronas de acero inoxidable. Se realizaron controles post tratamiento. El tratamiento de rehabilitación integral tuvo un impacto positivo en la paciente ya que se mejoró el desenvolvimiento de las funciones masticatorias y estéticas.

ДОСЛІДЖЕННЯ ВПЛИВУ ТОВЩИНИ НАРІЗУВАННЯ ПЛОДІВ ТА КОРЕНЕПЛОДІВ НА ПЛОЩУ ПОВЕРХНІ ШМАТОЧКІВ

Чипси з овочево-фруктової сировини належать до продуктів здорового харчування, популярність яких серед споживачів різного віку зростає щороку. Технологія виготовлення чипсів з овочево-фруктової сировини передбачає операції нарізування плодів і коренеплодів та сушіння їх шматочків. Тривалість сушіння та витрати енергії на процес залежать від площі поверхні шматочків і їх товщини. Що більша площа поверхні шматочків та менша їх товщина, то інтенсивніше відбувається сушіння сировини. У статті викладені результати дослідження впливу товщини нарізування плодів та коренеплодів різної форми на площу поверхні шматочків. Для розрахунку площі поверхні шматочків сировини запропоновані моделі плодів та коренеплодів у формі геометричних тіл: сфера, циліндр, зрізаний конус, сплюснутий еліпсоїд обертання, витягнутий еліпсоїд обертання. У результаті моделювання одержані теоретичні залежності для розрахунку площі поверхні шматочків залежно від форми моделі плода чи коренеплоду і способу їх нарізування. За результатами розрахунків встановлено, що зі зменшенням товщини нарізування відбувається збільшення площі поверхні шматочків. Порівняння результатів теоретичного розрахунку площі поверхні шматочків, що отримані у результаті нарізування моделей яблука та груші, з результатами експериментального визначення площі поверхні шматочків вказує на адекватність запропонованих розрахункових моделей.

Optimization of Input Cutting Parameters on Cutting Force During Vortex Tube Jet Assisted Machining of Ti-6Al-4V.

Titanium alloy materials machining is difficult, expensive and leads to wear and tear of the tool. The improvement in the tool life and use of optimal process parameters during machining is necessary to obtain better work piece surface finish. Here main aims to evaluate the effect of input process parameters on cutting force in Vortex Tube Jet Assisted CNC Machining of Titanium Alloy material. Taguchi L27 orthogonal array design matrix were used for experimentations by employing a Vortex Tube Jet Assisted cooling system. The significantly affecting process parameters are identified through ANOVA, and optimal parameters were identified using Taguchi and RSM. A mathematical model is proposed to estimate cutting forces based on selected input process parameters. The result reveals that the most influencing parameter is depth of cut (d). Whereas cutting speed and feed are influences very less. The cutting force (Fc) estimated from the proposed model is in close agreement with experimental results.

Optimization of Input Cutting Parameters on Cutting Force During Vortex Tube Jet Assisted Machining of Ti-6Al-4V.

Titanium alloy materials machining is difficult, expensive and leads to wear and tear of the tool. The improvement in the tool life and use of optimal process parameters during machining is necessary to obtain better work piece surface finish. Here main aims to evaluate the effect of input process parameters on cutting force in Vortex Tube Jet Assisted CNC Machining of Titanium Alloy material. Taguchi L27 orthogonal array design matrix were used for experimentations by employing a Vortex Tube Jet Assisted cooling system. The significantly affecting process parameters are identified through ANOVA, and optimal parameters were identified using Taguchi and RSM. A mathematical model is proposed to estimate cutting forces based on selected input process parameters. The result reveals that the most influencing parameter is depth of cut (d). Whereas cutting speed and feed are influences very less. The cutting force (Fc) estimated from the proposed model is in close agreement with experimental results.

THE EFFECT OF CUTTING TOOL WEAR ON THE RATE OF CORROSION WEAR OF A MACHINED MATERIAL

A possible variant for calculated estimation of the degree of the impact of the cutting tool wear on the value of the part’s surface layer wear obtained during processing with the edge tool, due to atmospheric corrosion, is presented. The feature is the evaluation of the wear rate and its numerical value depending on the tool wear, roughness parameters of the work piece surface, and the degree of cold hardening of the surface layer, as well as parameters of the technological machining conditions (cutting conditions, geometry of the tool cutting part, properties of the machined and the tool materials).

Low Environmental Impact Cleaning Technology with Ozone Micro-Bubbles Generated by a Venturi Tube

Cleaning technology is widely used to remove oil or resist from metal and semiconductor and soon. However, it causes high cost and severe environmental impacts because of the sewage disposal. Owing to strong oxidizing ability and self-decomposing power, ozone micro-bubbles generated by a Venturi tube was proposed. The purpose of this study is to research the capability of ozone micro-bubbles and improve the cleaning mechanism. In this study, we focus on the microbubble generator with a Venturi tube. We visualized the Venturi Tube by a high-speed camera to measure the bubble diameter. We also measure the shear stress near the test piece surface by using PIV. And by titration with Potassium iodide, ozonated water and ozone gas concentration are measured. Ozone gas is well dissolved after passing through the Venturi tube. Also, brass test pieces applied with cutting oil and latex resin are washed by using bubbly flow with ozone micro-bubbles. It has been confirmed that ozone micro-bubbles are able to clean the test pieces efficiently.

Simple Discriminatory Methodology for Wear Analysis of Cutting Tools: Impact on Work Piece Surface Morphology in Case of Differently Milled Kinetics Steel H13.

Recently, there is growing interest in optimisation of finishing process thanks to the technologies to follow online the wear of cutting tools. In the present paper, one of the cheapest and simplest non-contact methodologies is described in detail and investigated with robustness evaluation. To simulate the finishing operation of a die, in this study, two cavities were designed in AISI H13 steel. Different inserts corresponding to PVD-(Ti,Al)N coated cemented carbide tool were tested. The described methodology is easy to be applied in manufacturing cutting machining with the opportunity to be implemented on machining processes to follow reasonably wear process of cutting tools.

Influences of Horizontal and Vertical Build Orientations and Post-Fabrication Processes on the Fatigue Behavior of Stainless Steel 316L Produced by Selective Laser Melting.

In this paper, the influences of build orientation and post-fabrication processes, including stress-relief, machining, and shot-peening, on the fatigue behavior of stainless steel (SS) 316L manufactured using selective laser melting (SLM) are studied. It was found that horizontally-built (XY) and machined (M) test pieces, which had not been previously studied in the literature, in both stress-relieved (SR) or non-stress-relieved (NSR) conditions show superior fatigue behavior compared to vertically-built (ZX) and conventionally-manufactured SS 316L. The XY, M, and SR (XY-M-SR) test pieces displayed fatigue behavior similar to the XY-M-NSR test pieces, implying that SR does not have a considerable effect on the fatigue behavior of XY and M test pieces. ZX-M-SR test pieces, due to their considerably lower ductility, exhibited significantly larger scatter and a lower fatigue strength compared to ZX-M-NSR samples. Shot-peening (SP) displayed a positive effect on improving the fatigue behavior of the ZX-NSR test pieces due to a compressive stress of 58 MPa induced on the surface of the test pieces. Fractography of the tensile and fatigue test pieces revealed a deeper understanding of the relationships between the process parameters, microstructure, and mechanical properties for SS 316L produced by laser systems. For example, fish-eye fracture pattern or spherical stair features were not previously observed or explained for cyclically-loaded SLM-printed parts in the literature. This study provides comprehensive insight into the anisotropy of the static and fatigue properties of SLM-printed parts, as well as the pre- and post-fabrication parameters that can be employed to improve the fatigue behavior of steel alloys manufactured using laser systems.

Genetic algorithm-based drilling burr minimization using adaptive neuro-fuzzy inference system and support vector regression

Burrs are undesirable materials beyond the work piece surface during drilling or other machining processes, thus this should be as less as possible during manufacturing. The experimental study has been conducted according to the full factorial design method. A total of 27 experiments were conducted by drilling on an Aluminum 6061T6 plate by choosing three factors and three levels of process parameters like drill diameter, point angle and spindle speed. In this research article, two predictive models, namely, adaptive neuro-fuzzy inference system and support vector regression, are developed using experimental data to estimate burr height and burr thickness. Then, these predictive models have been used to find out optimum process parameters for minimum burr height and burr thickness using genetic algorithm. It has been found that both the models are able to predict burr size and thickness with good accuracy, while the adaptive neuro-fuzzy inference system performs better than support vector regression.

Comparative analysis of low-temperature PVD-based TiN nano-thin-film-coated and -uncoated TNMG inserts in dry machining

ABSTRACTTitanium nitride (TiN) is a hard-ceramic material having excellent wear and corrosion resistance properties. In this study, TiN coating has been deposited on carbide cutting inserts by a low-temperature cathodic arc phsical vapor deposition (PVD) system. Comparative analysis of machining performance, based on tool life and work piece surface roughness, has been done between the TiN-coated carbide cutting inserts and uncoated carbide cutting inserts in dry machining of medium carbon AISI 1045 steel. Design of experiments (DOE) technique along with response surface regression has been used for the optimization of machining parameters. The most significant factor affecting the surface roughness of the work piece in dry machining was found to be the feed rate. TiN-coated carbide cutting inserts showed 15% improvement in the surface roughness of work piece and 60% improvement in tool life as compared to uncoated carbide cutting inserts.

Effectiveness of edible coating based on chitosan and Natamycin on biological, physico-chemical and organoleptic attributes of Iranian ultra-filtrated cheese

Edible coatings can be applied on the surface of fruits and food pieces to improve their nutritional and sensory qualities. Present study focuses on the effects of applied edible coating formulation containing 1.6% W/V chitosan and 18.5 ppm Natamycin, on the surface of Iranian Ultra-filtrated (UF) cheese and evaluates biological, physico-chemical and organoleptic attributes of the coated cheeses as compared to those of the control samples, during 6 weeks of storage at temperature of 4 ± 2 °C. Coated and control samples were analyzed for bacterial total count, molds and yeasts population, coliform count and starter populations, as biological characteristics. pH, acidity, firmness, and salt, moisture, dry mater, fat and fat in dry mater contents were evaluated for both samples, as their physico-chemical properties. Appearance, odor and flavor, taste, texture and overall acceptability were evaluated for both coated and control cheese samples at weeks 3 and 6 of storage, as their sensorial attributes. Sensorial analysis indicated that, however there were insignificant differences between the values of sensory parameters for both samples at week 6, but, provided coating could significantly maintained sensory attributes of the coated cheese as compared to those of the control samples, at week 6 of storage.

Anti-CD34-Grafted Magnetic Nanoparticles Promote Endothelial Progenitor Cell Adhesion on an Iron Stent for Rapid Endothelialization.

Iron stents, with superior mechanical properties and controllable degradation behavior, have potential for use as feasible substitutes for nondegradable stents in the treatment of coronary artery occlusion. However, corrosion renders the iron surface hard to modify with biological molecules to accelerate endothelialization and solve restenosis. The objective of this study is to demonstrate the feasibility of using endothelial progenitor cells (EPCs) to rapidly adhere onto iron surfaces with the assistance of anti-CD34-modified magnetic nanoparticles. Transmission electron microscopy, Fourier transform infrared spectroscopy, Thermogravimetric analysis, XRD, and anti-CD34 immunofluorescence suggested that anti-CD34 and citric acid were successfully modified onto Fe3O4, and Prussian blue staining demonstrated the selectivity of the as-prepared nanoparticles for EPCs. Under an external magnetic field (EMF), numerous nanoparticles or EPCs attached onto the surface of iron pieces, particularly the side of the iron pieces exposed to flow conditions, because iron could be magnetized under the EMF, and the magnetized iron has an edge effect. However, the uniform adhesion of EPCs on the iron stent was completed because of the weakening edge effect, and the sum of adherent EPCs was closely linked with the magnetic field (MF) intensity, which was validated by the complete covering of EPCs on the iron stent upon exposure to a 300 mT EMF within 3 h, whereas almost no cells were observed on the iron stent without an EMF. These results verify that this method can efficiently promote EPC capture and endothelialization of iron stents.

Determination of the allowable minimum thickness of protective coating for welding in carbon dioxide

Among industrial technologies, carbon dioxide welding occupies a leading position. However, this welding method is characterized by increased spattering of metal and splashing it on the welded piece of work. A protective coating layer applied to metal is effective means of preventing the consequences of this disadvantage. The paper developed the method for determining the minimum allowable thickness of the coating, sufficient to prevent the interaction of molten metal drops with the surface of the welded pieces of work.