Metal Work Research Articles

Partially Dehydrated Castor Oil-Based Isoalkyl and Polyol Esters as Potential Base Stocks for Industrial Applications

Partially dehydrated castor oil (PDCO) which is of less use in the paint and furniture coating formulations has been modified to develop biolubricant base stocks. PDCO (44.1%, non-conjugated linoleic acid; 32%, conjugated linoleic acid (18:2) isomers and 15.3% ricinoleic acid) obtained from a local industry was hydrolyzed under alkaline conditions. The fatty acids obtained (PDCFAs) in 98% yields were reacted with polyols namely 2-ethyl hexanol, neopentyl glycol, trimethylol propyl, pentaerythritol to obtain respective isoalkyl erters and esters of polyol with >95% yield. The base stocks exhibited very high viscosity indices (187.288 to 187.687), excellent pour point (-25 to -40 ºC) and high flash points (212 to 317 ºC) required for a variety of industrial applications namely metal working, hydraulic, forging, cutting fluid, gear oil applications. The tribological properties of PDCO, exhibited very low WSD (0.72-0.79 mm) and WSVs (0.82-0.83 mm3) with high load carrying capacities (180-220 kg) indicating low friction and less energy losses between the sliding surfaces. This was also accompanied by very high thermo-oxidation stabilities [Oxidation stability (230-242 ºC); Onset temperature (300-381 ºC)] of the base stacks due to branching. Overall all the PDCO isoalkyl and polyol esters exhibited excellent properties suitable for a wide range of industrial applications on par with mineral oil based lubricants.

Towards the factory 4.0 Convergence and divergence of lean models in Italian automotive plants

This paper studies the interplay in terms of techno-organisational change between the adoption of I4.0 technologies and lean production systems. Leveraging on the results of two field-work analyses conducted under a collaboration with the Sabattini Foundation and the metal workers trade union FIOM in the period 2016-2018, we compare an ensemble of factories producing both high-end/highly customised and low-end products. Emerging patterns of convergence and divergence in the techno-organisational configurations of these factories confirm that this wave of technological innovation is far from leading to total automation or the digital revolution. On the contrary, it appears to be integrated into the historical trend of 'leanification' of production processes in the automotive sector, despite the organisational variety shaped by the actual implementation of this production model.

Towards Factory 4.0 Convergence and divergence of lean models in Italian automotive plants

This paper studies the interplay in terms of techno-organisational change between the adoption of I4.0 technologies and lean production systems. Leveraging on the results of two field-work analyses conducted under a collaboration with the Sabattini Foundation and the metal workers trade union FIOM in the period 2016-2018, we compare an ensemble of factories producing both high-end/highly customised and low-end products. Emerging patterns of convergence and divergence in the techno-organisational configurations of these factories confirm that this wave of technological innovation is far from leading to total automation or the digital revolution. On the contrary, it appears to be integrated into the historical trend of 'leanification' of production processes in the automotive sector, despite the organisational variety shaped by the actual implementation of this production model.

Steelmakers: The Marriage of Entrepreneurship and Finance in New Glasgow and Halifax, 1883–1904

One of the most technically advanced, fully integrated steel companies in Canada, the Nova Scotia Steel Company, began as Hope Iron Works, established in 1872 by Graham Fraser and Forrest McKay, two New Glasgow metal workers, with a small investment. In 1882, in response to the 1879 National Policy, Hope was incorporated into a new company with a board consisting mostly of New Glasgow merchants and entrepreneurs and John F. Stairs of Halifax. The Stairs' role in the development of “Scotia,” as it was called, has either been downplayed or largely ignored. From careful beginnings, the new company made rapid progress, installing new machinery and adding many new products. By the summer of 1901 the Nova Scotia Steel and Coal Co. was brimming with optimism and set about the task of becoming a fully integrated steel company. What had begun as a $4,000 investment in 1872 by two New Glasgow visionaries with their eight employees had become, by Nova Scotia standards, an industrial colossus with $4.5 million in assets and well over 1,500 employees at three locations, a triumph of inter-regional cooperation. The process of growth of this industrial giant from such humble beginnings is a tale of Maritime high finance in the era of the National Policy.

Influence of applied plasma power on degradation of L-proline in an inductively coupled RF plasma reactor

Surface treatments such as heat treatments, paints, plasma treatments and galvanizing are important in metal working industry. In those treatments, the required adhesion characteristics can be limited if contaminants are present, so there is a need to clean these surfaces. Conventional processes can be costly, some generated waste may be environmentally hazardous and, in some cases, due to part geometry, they are not effective. Alternatively, plasma treatments which are considered to be environmentally clean, more efficient and with lower operating costs can overcome those difficulties. Due to the reactional complexity of these treatments, there are many fields to be researched, such as which reactions are due to impacts of (neutral) chemical species and which are due to excited species and radiation. The present work aims to verify the interactions between Ar-10%O2 plasma using amino acid L-proline in an inductively coupled radiofrequency plasma. This study showed that oxidative plasma promotes high degradation of the sample. A gas analyzer (quadrupole mass spectrometer) coupled to the gas outlet was used and many gaseous products are detected during treatment, such: H2, H2O, CO, NO (Nitric Oxide) and CO2 while L-proline undergoes intense degradation. The conclusions allow to state that the interaction between the Ar/O2 plasma and L-proline promotes intense degradation through the breakdown of the heterocyclic ring of the molecule.

Variants of TIG welding process for improvement of weld penetration depth - A review

This article deals with the various process modifications that occurred in the tungsten inert gas welding process over a decked of time. The conventional TIG welding process usually offers a shallow weld penetration (up to 5 mm). Due to this limited depth of penetration, the industrial applications of this process are very limited and used only for sheet metal working. This article focuses on the various modification that has been made in the conventional TIG welding process to improve the process capabilities. Mainly flux assisted TIG welding, pulse current TIG welding, keyhole TIG welding, multi-electrode TIG welding, TIP-TIG welding process, and their hypothesis responsible to improve the weld penetration were discussed. The effect of various process parameters of these process variants on weld penetration was also discussed. So, this article will help in strengthening the future research trend in TIG welding for enhancement of its industrial application and capability of the process.

Optimization of process parameters in ultrasonic machining using integrated AHP-TOPSIS method

The process by virtue of which holes and cavities are formed in a metal work piece with the help of shaped tools, high frequency mechanical motion and abrasive slurry is known as Ultrasonic Machining Process. Its working principle is completely different from the other traditional machining processes such as laser beam machining and electrical discharge devices. This is developed machine removal processes in which the work material is less damaged by the thermal energy and it also introduce significant level of residual stress which is important for survival of the work material. This character of the process makes USM more enhanced and better machine job characteristics. This characteristic is also required for determining the optimal control parameter settings of an USM process’s is a non-traditional machining process in which abrasive content in slurry are driven against work by tool oscillating at low amplitude and high frequency. In this research paper stainless steel is used as tool material in the whole process and zirconia bio ceramic plate is taken as a work piece material. The process parameters are considered as feed rate, slurry concentration, power rating and grit size. Through this work, it is found that responses highly correlated with correlation coefficient, which justifies the application of MCDM as an optimization tool. The optimization studies are carried out on an ultrasonic machining process with multi response characteristics depend on the multi criteria decision making methodology (MCDM), using technique for order preference by similarity to ideal solution (AHP-TOPSIS) approach are described in this paper. The final results of this paper indicate the effectiveness of USM using MCDM method for different USM parameters to produce high quality parts made of zirconia Bio-ceramics with excellent productivity.

On use of interlocking structures in plastic metal working

An effective method to increase the rigidity and reliability of materials and structures by choosing a rational geometry of structural elements and conditions for their interaction with each other is proposed. This method, associated with interlocking structures, has found application in the creation of new technical solutions in metallurgy.

Application of Ergonomic Principles on Metal Work Design For Global Utilization in Technical College Classrooms in Rivers State

Application of Ergonomic Principles on Metal Work Design For Global Utilization in Technical College Classrooms in Rivers State

Characterisation, Performance and Optimisation of Nanocellulose Metalworking Fluid (MWF) for Green Machining Process

The present research attempts to develop a hybrid coolant by mixing alumina nanoparticles with cellulose nanocrystal (CNC) into ethylene glycol-water (60:40) and investigate the viability of formulated hybrid nanocoolant (CNC-Al2O3-EG-Water) towards enhancing the machining behavior. The two-step method has been adapted to develop the hybrid nanocoolant at various volume concentrations (0.1, 0.5, and 0.9%). Results indicated a significant enhancement in thermal properties and tribological behaviour of the developed hybrid coolant. The thermal conductivity improved by 20-25% compared to the metal working fluid (MWF) with thermal conductivity of 0.55 W/m℃. Besides, a reduction in wear and friction coefficient was observed with the escalation in the nanoparticle concentration. The machining performance of the developed hybrid coolant was evaluated using Minimum Quantity Lubrication (MQL) in the turning of mild steel. A regression model was developed to assess the deviations in the tool flank wear and surface roughness in terms of feed, cutting speed, depth of the cut, and nanoparticle concentration using Response Surface Methodology (RSM). The mathematical modeling shows that cutting speed has the most significant impact on surface roughness and tool wear, followed by feed rate. The depth of cut does not affect surface roughness or tool wear. Surface roughness achieved 24% reduction, 39% enhancement in tool length of cut, and 33.33% improvement in tool life span. From this, the surface roughness was primarily affected by spindle cutting speed, feed rate, and then cutting depth while utilising either conventional water or composite nanofluid as a coolant. The developed hybrid coolant manifestly improved the machining behaviour.

Numerical simulation of novel designed perovskite/silicon heterojunction solar cell

In this work, novel designed solar cell is proposed for first time for doped perovskite based silicon heterojunction solar cells where (n/p)-type doped perovskite used as ultra-thin emitter layer and (p/n)-type silicon as absorber layer. Performance of two different types of solar cells, n-type doped perovskite with p-type based crystalline silicon (p-cSi) solar cells and p-type doped perovskite with n-type based crystalline silicon (n-cSi) solar cells are studied and highest efficiency of 28.82% and 29.48% respectively are achieved by optimizing their properties. Thicknesses of silicon wafer and perovskite layer, band gap of MAPbI3 layer, doping density of ultra-thin perovskite (emitter) layer, doping density of c-Si layer, texturing of silicon wafer, metal work function of different materials at front contact and back contact & its band bending on using different metals, and role of ZnO and ITO as conducting surface layer has been studied and optimized in the present work. AFORS-HET automat simulation software is used to study the performance of these simulated solar cells.

Nanojunction Material Effect on the Photoelectric Response of Single-Wall Carbon Nanotube Rectennas.

To optimize the performance of carbon nanotube (CNT)-based rectennas, we have studied the effect of metal work function on the photodetection characteristics. Two materials of conducting nanoprobes, namely, gold (Au) and platinum (Pt), have been used to form a rectifying diode at the interface with the CNT. The electrical and optical characteristics of single-wall carbon nanotubes (SWCNTs) dispersed on top of a SiO2/Si substrate have been investigated using a conductive mode atomic force microscope (C-AFM). The I–V measurements performed for both diodes have exhibited an explicit rectification behavior with high sensitivity of a CNT-based rectenna to light. It has been observed that the lower work function metal (Au) leads to a higher on/off current ratio than the high work function metal (Pt). These experimental observations will be explained using the material characterization of the complete system along with representative energy-band diagrams.

Recent Advances in Hollow Cathode Technology for Plasma-Enhanced ALD—Plasma Surface Modifications for Aluminum and Stainless-Steel Cathodes

Recent designs have allowed hollow cathode gas plasma sources to be adopted for use in plasma-enhanced atomic layer deposition with the benefit of lower oxygen contamination for non-oxide films (a brief review of this is provided). From a design perspective, the cathode metal is of particular interest since—for a given set of conditions—the metal work function should determine the density of electron emission that drives the hollow cathode effect. However, we found that relatively rapid surface modification of the metal cathodes in the first hour or more of operation has a stronger influence. Langmuir probe measurements and hollow cathode electrical characteristics were used to study nitrogen and oxygen plasma surface modification of aluminum and stainless-steel hollow cathodes. It was found that the nitridation and oxidation of these metal cathodes resulted in higher plasma densities, in some cases by more than an order of magnitude, and a wider range of pressure operation. Moreover, it was initially thought that the use of aluminum cathodes would not be practical for gas plasma applications, as aluminum is extremely soft and susceptible to sputtering; however, it was found that oxide and nitride modification of the surface could protect the cathodes from such problems, possibly making them viable.

A geostatistical approach to estimating source apportionment in urban and peri-urban soils using the Czech Republic as an example

Unhealthy soils in peri-urban and urban areas expose individuals to potentially toxic elements (PTEs), which have a significant influence on the health of children and adults. Hundred and fifteen (n = 115) soil samples were collected from the district of Frydek Mistek at a depth of 0–20 cm and measured for PTEs content using Inductively coupled plasma—optical emission spectroscopy. The Pearson correlation matrix of the eleven relevant cross-correlations suggested that the interaction between the metal(loids) ranged from moderate (0.541) correlation to high correlation (0.91). PTEs sources were calculated using parent receptor model positive matrix factorization (PMF) and hybridized geostatistical based receptor model such as ordinary kriging-positive matrix factorization (OK-PMF) and empirical Bayesian kriging-positive matrix factorization (EBK-PMF). Based on the source apportionment, geogenic, vehicular traffic, phosphate fertilizer, steel industry, atmospheric deposits, metal works, and waste disposal are the primary sources that contribute to soil pollution in peri-urban and urban areas. The receptor models employed in the study complemented each other. Comparatively, OK-PMF identified more PTEs in the factor loadings than EBK-PMF and PMF. The receptor models performance via support vector machine regression (SVMR) and multiple linear regression (MLR) using root mean square error (RMSE), R square (R2) and mean square error (MAE) suggested that EBK-PMF was optimal. The hybridized receptor model increased prediction efficiency and reduced error significantly. EBK-PMF is a robust receptor model that can assess environmental risks and controls to mitigate ecological performance.

High efficiency performance of eco-friendly C2N/FASnI3 double-absorber solar cell probed by numerical analysis

In this paper, the double-absorber solar cell based on C2N and FASnI3 as echo-friendly absorber materials has been modelled and simulated. Numerical simulations were performed by utilizing the one-dimensional solar cell capacitance simulator (SCAPS-1D). The study shows that optimizing the parameters of the solar cell layers is vital to achieving high device performance. Decreasing the thickness of the buffer layer (IGZO) and C2N to 10 nm and increasing the thickness of FASnI3 to 1000 nm paved the device toward high performance. Increasing the electron affinity of FASnI3 showed a positive impact on the device performance, reflecting its rule as a key parameter in bands alignement of the absorber layer. In the electron affinity range, 4.3 eV–4.6 eV, the power conversion efficiency of 25.32% is obtained. This value is higher than that of a single absorber layer solar cell using the same absorber materials quoted in previous studies. Additionally, the heavy doping density of both absorber layers deteriorates the device performance. The optimal performance is achieved with a doping density of less than 1×1018 cm−3 in C2N and 1×1017 cm−3 in FASnI3. Furthermore, the influence of the back contact work function is explored by using different metals as a back contact. The results show that high metal work function is essential for enhancing solar cell performance, and nickel is the most promising material for the solar cell industry. Finally, the simulations show that the device operates optimally at 300 K, and increasing the temperature opposes the solar cell performance.

Prediction of weldment mechanical properties in GMAW with robot-assisted using fuzzy logic systems

Welding operation decides the quality of product standards in all metal work products like automobiles, aerospace vehicles, and many more. The quality of the welding process is more reliable by automating the process with robots. In this research work, the GMAW operation is automated with the ‘Fanuc Robot Arc mate 100iC/12’ robot. The material characteristics such as ultimate tensile strength, hardness, and impact strength of weldments are predicted using a fuzzy system using triangular membership function (TrMF) and trapezoidal membership function (TMF). The simulated results are validated by comparing with experimental work, the experiments are designed using orthogonal array L18, and material characteristics are studied using fractography test. The fuzzy system is trained with experimental results using the IF-Then rule base with the help of the L18 orthogonal array. The inference system has predicted the accuracy rate of weldment mechanical properties, showing a lower error rate.

Two-terminal vertical thyristor using Schottky contact emitter to improve thermal instability

In a two-terminal-electrode vertical thyristor, the latch-up and latch-down voltages are decreased when the memory operation temperature of the memory cells increases, resulting in a severe reliability issue (i.e. thermal instability). This study fundamentally solves the thermal instability of a vertical-thyristor by achieving a cross-point memory-cell array using a vertical-thyristor with a structure of vertical n++-emitter, p+-base, n+-base, and p++-emitter. The vertical-thyristor using a Schottky contact metal emitter instead of an n++-Si emitter significantly improves the thermal stability between 293 K and 373 K. Particularly, the improvement degree of the thermal stability is increased significantly with the use of the Schottky contact metal work function. Because the thermal instability (i.e. degree of latch-up voltage decrement vs. memory operation temperature) decreases with an increase in the Schottky contact metal work function, the dependency of the forward current density between the Schottky contact metal and p+-Si based on the memory operation temperature reduces with increase in the Schottky contact metal work function. Consequently, a higher Schottky contact metal work function produces a higher degree of improvement in the thermal stability, i.e. W (4.50 eV), Ti (4.33 eV), Ta (4.25 eV), and Al (4.12 eV). Further research on the fabrication process of a Schottky contact metal emitter vertical-thyristor is essential for the fabrication of a 3D cross-point memory-cell.

Automatic Pneumatic Sheet Metal Feeding and Cutting Machine

Abstract: Today in the rapid competition of the industries to get the best quality of the product in the minimum required time is the main aim of industries. To get the best quality and maximum production most advanced machines are used. But there are no facts that use only the advanced machines, to maintain their performance is real requirement of the industries, also to give proper facilities to the workers with good environmental condition and to reduce their efforts is one of the objects to achieve the best quality and high production. Sheet metal is simply a metal formed into thin and flat pieces. It is one of the fundamental forms used in metal working and can be cut and bent into a variety of different shapes. Countless everyday objects are constructed of the material. Thicknesses can vary significantly, although extremely thin thicknesses are considered foil or leaf, and pieces thicker than 6 mm (0.25 in) are considered plate. Sheet metal also has applications in car bodies, airplane wings, medical tables, roofs for buildings (Architectural) and many other things. Sheet metal of iron and other materials with high magnetic permeability, also known as laminated steel cores, has applications in transformers and electric machines. There are three primary procedures in Layout. They are Parallel, Radial, and Triangulation. The major aim to our experiment is to study about pneumatic control system, study about double acting cylinder, study about the advantage of pneumatic hand operated valve and study about high speed blade. We are using scissors for simple sheet metal cutting. It is a manual method so that sheet metals are to be wasted sometimes because of mistakes happened such as wrong dimensions etc., and also even a simple cutting may take long time. We are using a pneumatic system for sheet metal cutting in an easy way. It is operated by a pneumatic hand lever of two ways control valve. Control valve is operated by a compressor. Keywords: Pneumatic, Automation, Sheet Metal, Pneumatic, Valve, Cutting Machine

Numerical optimization of (FTO/ZnO/CdS/CH3NH3SnI3/GaAs/Au) perovskite solar cell using solar capacitance simulator with efficiency above 23% predicted

The presented study deals with the investigations of the methyl ammonium tin halide (CH3NH3SnI3) based perovskite solar cells for optimized device performance using solar capacitance simulations software. Several necessary parameters such as metal work functions, thickness of structural layers, charge carrier’s mobility and defect density have been explored to evaluate the device performance. Calculations reveal that for the best efficiency of device the maximum thickness of the perovskite (CH3NH3SnI3) absorber layer must be 4.2 μm. The thickness values of 0.01 μm for ZnO electron transport layer (ETL), 0.871 μm for GaAs hole transport layer and 0.001 μm for CdS buffer layer have been found which proved to be optimum for maximum power conversion efficiency (PCE) of 23.80% for the device. The variation of open circuit voltage (Voc), Short circuit current (Jsc), Fill Factor (FF %), quantum efficiency (QE) against thickness of all layers and interface defect densities in FTO/ZnO/CdS/CH3NH3SnI3/GaAs/Au composition have been critically explored and their crucial role for the device performance has been reported. Heterojunctions between ZnO-ETL and CdS buffer layers have shown improved device performance and PCE. Current investigations may prove to be useful for designing and fabrication of climate friendly, non-toxic and highly efficient solar cells.

Optimization of Hole Transport Layer Materials for a Lead‐Free Perovskite Solar Cell Based on Formamidinium Tin Iodide

Recently, lead‐based perovskite solar cells have been mainly studied; however, these cells suffer from two main problems: the toxicity of lead and the instability of the devices, which limit their commercialization. Herein, a theoretical investigation of a lead‐free perovskite solar cell based on formamidinium tin iodide (HC(NH2)2SnI3) with the general architecture: glass/FTO/WS2/HC(NH2)2SnI3/HTL/Au is reported. All calculations are performed with the SCAPS‐1D solar cell simulator. Two inorganic (CuSCN and Cu2O) and two organic (P3HT and D‐PBTTT‐14) hole transport layer (HTL) materials are tested in this model. The effect of the external operating temperature and different metal work functions of the back contact of the cell on the overall performance of the devices is also studied. Simulations showed that, with the introduction of CuSCN, Cu2O, and P3HT as HTLs, the device can attain a remarkable efficiency of ≈21%. All the modeled devices showed remarkable performance of above 20% at higher temperatures of 380–420 K but degraded slightly when this range is exceeded. Relatively cheaper Pt, Ni, and Pd metals perform better, thus, can replace gold. These simulation results can provide avenues and directions for future advancement of the performance of lead‐free perovskite solar cells.