Iron Cylinder Research Articles

Metagratings for Waterborne Sound: Various Functionalities Enabled by an Efficient Inverse-Design Approach

A controllable and steerable transport of acoustic wave signals along preferred paths with unitary efficiency is highly desired for underwater acoustic applications such as underwater communication, navigation, and tracking. Here we present a systematical study of a class of simply structured acoustic metagratings containing iron cylinders only. Through diffraction analysis and a genetic-algorithm-assisted optimization process, we propose a powerful inverse-design approach that can faithfully and promptly produce desired wave-front manipulation effects. Various interesting diffraction-engineering functionalities such as perfect beam splitting, anomalous reflection and transmission, retroreflection, and highly asymmetric transmission response are unambiguously demonstrated with unitary efficiency. These simply structured metagrating configurations, as well as the efficient inverse-design methodology behind them, are expected to be useful in the design of multifunctional acoustic planar devices for diverse underwater applications.

Tribological assessment of NiCr, Al2O3/TiO2, and Cr3C2/NiCr coatings applied on a cylinder liner of a heavy-duty diesel engine

Internal combustion engines consume about 90% of fuel refined from crude oil which supplies 30% of the annual global flow of energy. Heavy-duty diesel engines are the primary source of power used in highways, marine, railroads, and power stations. The right coating can improve the tribological properties of cylinder liners and increase the mechanical efficiency of an engine. Also, it can help to extend the maintenance periods, and enhance the reliability of the vehicles. In this research, tribological and economic evaluations were performed for coated and uncoated substrates from a cylinder liner of a heavy-duty diesel engine, aiming to lower friction, wear rate, and maintenance cost. A reciprocating friction test was conducted under dry condition using Wolfram carbide (tungsten carbide) ball applied a 10 N normal load on a ball on disk geometry. The cylinder liner was made of gray cast iron, and the substrates obtained were coated with three different coating materials (Cr3C2/NiCr, NiCr, and Al2O3/TiO2) through the thermal spray and high-velocity oxy-fuel coating process. Tribological evaluations showed that the substrates coded with Al2O3/TiO2 and Cr3C2/NiCr had the lowest friction coefficient and wear rate. The most economical coating was Al2O3/TiO2, being able to supply about 61% lower coefficient of friction and 94% less wear rate relative to the uncoated sample, for the price of one-third of the Cr3C2/NiCr coating and one half of a new gray cast iron cylinder liner.

Tribological performance of nano-diamond composites-dispersed lubricants on commercial cylinder liner mating with CrN piston ring

AbstractThis work investigated the effect of nanodiamond (ND) additives on the tribological properties of CrN-coated piston ring mating with the chromium-plated and BP alloy iron cylinder liners, which is one of the key friction pairs in the internal combustion engines. To enhance the dispersion of the NDs in the base oil, the surface of ND particles was modified with polyaniline viain situpolymerization. The friction and wear as well as the scuffing characteristics of the friction pair lubricated with different contents of ND composite-added base oil were evaluated by using the reciprocating tribotests, which are close to the actual conditions. The wear surface morphologies and elements distribution were analyzed to explore the wear behaviors and the associated mechanisms of friction pairs under the lubrication incorporated with the ND composites. The results show that the ND additive is beneficial for the pair of Cr liner and CrN-coated piston ring in the friction and wear as well as scuffing properties, and the best concentration of ND additive is expected to be around 1 wt%. But for the BP liner, the developed nanocomposite has a negative impact. The friction force and the wear loss of the pair lubricated by the ND composite-added oil are even worse than that tested with the base lubricating oil.

Tribological behavior of chrome-deposited SAE9254 grade steel top compression piston ring under lubrication starvation and mild extreme pressure lubrication

This article reports tribological studies of piston ring/cylinder liner tribo-contact to evaluate the scuffing failure under dry sliding conditions and its minimization with mild extreme pressure lubrication. The tribological conjugation tested employs a piston ring of SAE9254 grade steel substrate with plasma-sprayed chromium coating of 42 µm and ISO R185220 grade gray cast iron cylinder liner. A conformal, cylinder inscribed in cylindrical cavity contact was ensured to simulate actual dead center reciprocating between piston ring–cylinder liner interface. Tribotests were conducted under dry sliding, simulating lubrication starvation and sliding in extreme pressure additivation blend at a temperature of 200 °C with 10 mm stroke length and reciprocating velocity of 0.2 m s–1. The friction characteristics of the piston ring and cylinder liner samples in cited test conditions were studied as a function of load and continuously monitored throughout the tests. Optimal profilometry was employed for evaluating wear attributes. For surface morphology and allied surface characterization, energy-dispersive X-ray spectroscopy integrated scanning electron microscopy was used. For tribo-chemical interactions and film formation, the tribo-surfaces were further investigated with Raman spectroscopy. ASTM E-384 standard Vickers indentation microhardness and its precedence to tribological characteristics were evaluated. The extreme pressure lubrication is intended to potentially improve the scuffing résistance and optimization of coating material in achieving superior tribological characteristics. Superior lubricity, scuffing resistance and enhanced load-bearing capacity attributes were manifested by EP-PAO10 blend lubrication contrasting the surface deteriorations and scuffing failure ascribed to dry sliding.

Rotational Eddy Current Speed Sensor

A novel eddy current speed sensor is developed to measure the rotational speed of conductive objects. The sensor consists of one excitation coil and two pick-up coils around a rotating cylinder or rod. The sensor does not use magnetic yoke. For the analysis and experimental verification, we used 30 mm diameter non-magnetic aluminum and also magnetic solid iron cylinders. The calculated and measured speed ranges are up to 1200 r/min. A 2-D analytical method is developed to calculate sensor performance. A 2-D finite element is also used for simulations to compare results with the 2-D analytical method. A 3-D finite-element analysis is required to take into account significant 3-D effects due to the air coil configuration. The experimental results are presented at different steady-state speeds. The calculation results are compared with measurements to validate theoretical models and sensor performance. The eddy current speed sensor shows high linearity even at low speeds. For ferromagnetic rods, we suggest a novel double-layer configuration: non-magnetic conductive ring or shell on top of the iron rod minimizes the influence of the permeability changes. The main advantage of the novel sensor is that it has neither mechanical nor electrical contact to the rotating rod.

Investigation of using pumpkin seed oil methyl ester as a fuel in a boron coated diesel engine

In this study, pumpkin seed oil was converted into biodiesel using alkali-catalyzed transesterification. Physicochemical properties were examined based on ASTM standards and compared with commercial diesel fuel (D-2). To improve the performance of engine, combustion chamber components like piston head, cylinder liner, intake and exhaust valves were thermally coated. Boronizing method was applied for the first time in the coating of conventional cast iron cylinder liner surface to reduce heat transfer. 150 μm thick Fe2B layer was deposited on the surfaces. So, the conventional engine was converted into low heat rejection engine. In order to determine the insulation affect of Fe2B layer, 3-D finite element transient-state analyses were done to the both coated and standard cylinders. D-2 and PSME fuel blends were used as test fuels. Emission and performance of the coated engine (CE) have been investigated for both fuels. CE showed lower emission and higher performance. For D-2 and B-20 fuels; results showed that, CO decreased by 13–15%, HC decreased by 53–36%, smoke density decreased by 15–36%, respectively. But NOx emission increased by 11–37% for D-2/B-20 fuels, respectively. Besides, BTE for D-2/B-20 fuel increased by 10-10% while BSEC decreased by 3–9%, respectively.

Development of Residual Stresses in Al–Si Engine Blocks Subjected to Different Metallurgical Parameters

Light aluminum alloy engine blocks have successfully replaced heavy ferrous materials in order to enhance automobile fuel efficiency. Aluminum engine blocks with gray iron cylinder liners are prone to tensile residual stresses along the cylinder bridges, which may cause distortion and reduce engine efficiency. In this study, the sectioning technique was used as a means for measuring average residual stresses in critical regions in engine blocks subjected to different metallurgical parameters. It was found that the stresses could be higher than 100 MPa in tension after casting. Relaxation of residual stresses was observed after solution heat treatment, freezing treatment, and aging compared to the initial stage, depending on the geometry and size of the workpiece. Relaxation rate was found to be affected by the size of the workpiece.

On the use of heterogeneous thermomechanical and thermophysical material properties in finite element analyses of cast components

Cast components generally show a heterogeneous distribution of material properties, caused by variations in the microstructure that forms during solidification. Variations caused by the casting process are not commonly considered in structural analyses, which might result in manufacturing of sub-optimised components with unexpected in-use behaviour. In this paper, we present a methodology which can be used to consider both thermomechanical and thermophysical variations using finite element analyses in cast components. The methodology is based on process simulations including microstructure modelling and correlations between microstructural features and material properties. Local material data are generated from the process simulation results, which are integrated into subsequent structural analyses. In order to demonstrate the methodology, it is applied to a cast iron cylinder head. The heterogeneous distribution of material properties in this component is investigated using experimental methods, demonstrating local variations in both mechanical and physical behaviour. In addition, the strength-differential effect on tensile and compressive behaviour of cast iron is considered in the modelling. The integrated simulation methodology presented in this work is relevant to both design engineers, production engineers as well as material scientists, in order to study and better understand how local variations in microstructure might influence the performance and behaviour of cast components under in-use conditions.

Drying of paper: A review 2000–2018

Drying of paper during 2000–2018 is reviewed. The review includes new drying processes, multi-cylinder dryers, tissue and impingement drying, TAD-drying, infrared drying and energy use for drying of paper. It includes general aspects of infrared dryers but not drying of coated papers. Paper quality aspects, paper shrinkage and paper isotherms are not included. Impingement drying has been the most successful new technology with several applications while others such as impulse drying has not been commercialized mainly due to problems with paper quality parameters. One promising development is the introduction of steel instead of cast iron cylinders with increased heat transfer reducing the number of cylinders. Future research should focus on modeling the internal transport phenomena and to couple these phenomena to paper shrinkage and quality parameters. The influence of the fabric for the drying process needs more attention, understanding the drying process for new components such as microfibrillar cellulose in the stock and reducing energy use and increasing the amount of renewable energies for drying of paper.

Effect of additives on a surface textured piston ring–cylinder liner system

ABSTRACTLaser texturing of the surface is a known approach to improve the tribological performance of mechanical systems. Many studies focused on optimising surface texture parameters for the piston-ring cylinder liner (PRCL) system. However, little attention is given to explore the effect of the textured surface on additive film formation. In the present work, the effect of a laser textured surface on the formation of additives tribochemical films and its impact on the tribological performance of PRCL system is studied. Commercially available steel piston ring and grey cast iron cylinder liner are used as samples to carry out the experiments using linear reciprocating tribometer. Experiments are carried out at 75 N load, 0.1 Hz frequency and 80°C temperature, using polyalphaolefin as base oil mixed with different additives. It is found that dimples are interfering in the formation of tribo-chemical films. However, the hydrodynamic effect of dimples is contributing to the improvement of lubrication performance even in the presence of additives.

Wear Behavior of CuSn Coated Piston Ring Sliding against Nodular Cast Iron Cylinder Liner under Heavy-Duty Conditions

In order to investigate the friction and wear behavior between the nodular cast iron cylinder liner (Fe) and CuSn coated piston ring under heavy-duty conditions, piston rings with chromium(Cr) coating and CuSn-Cr coating were tested using the piston ring reciprocating liner test rig at the simulated working conditions of 56 MPa, 200 r/min, 190 °C. Compared with the Cr/Fe pair, the CuSn coating consumption of the CuSn-Cr/Fe pair made friction coefficient and cylinder wear loss decrease by 2.8% and 51.5%, respectively. Different size Sn patches worn from the CuSn coated piston ring were embedded into the cylinder liner surface based on the surface topography. This process was shown to reduce the surface roughness of a cylinder liner and form flatter plateau structures. Chemical elements analysis indicated that plateau structures on the cylinder liner surface matched with CuSn-Cr coated ring are helpful to promote the tribo-chemical reaction and generate the reactive products to protect the mutually contacted asperities.

Vibration control of a circular plate using parametric controller with phase shift adjustment

The article presents a vibration control method of a circular plate based on a controller with phase shift adjustment in the feedback loop (PSAF). The proposed controller combines the structures of the positive position feedback and strain rate feedback controllers, which are often used in vibration reduction systems. Additionally, the PSAF controller allows the adjustment of the phase shift of the controller to the object changes by tuning its parameters. An analytical model of bending vibration of the thin plate as well as the estimated model based on the autoregressive identification method with exogenous terms (ARX) is introduced. These two methods of obtaining the mathematical model are applied to develop the control algorithm for vibration cancellation. Vibrations of the plate are measured using a noncontact method – laser vibrometer. This method renders it easy to change the position of the beam on the test surface and ensures the high precision of the measurements. The control input is applied to the plate by an MFC disk that is attached to the plate at its center. The plate vibrations were excited by a loudspeaker located inside a cast iron cylinder. The designed controller was implemented and tested on a realtime platform - PowerDAQ with xPC Target environment. This article presents the concept, results of simulation tests, and implementation for the PSAF controller. Finally, the obtained results confirm the possibility of using the proposed solution to reduce the vibration of plates, indicating significant suppression of the targeted modes.

Experimental study on repairing of damaged cast iron cylinder heads by 3D printing arc welding system

To realize repairing of damaged cast iron cylinder heads by 3D printing arc welding system mainly composed of an industrial robot and an arc welding machine, the remanufacturing process flow of 3D printing arc welding system was introduced, and a single straight wall stacking experiment was designed. The effects of process parameters on the appearance quality and mechanical properties of welding pieces were studied. The forming laws of welding piece were obtained. The main conclusions include: The higher the preheating temperature, and interlayer temperature, the more obvious the effects of process parameters on the hardness of welding pieces, and the effects of preheating temperature are more evident than that of interlayer temperature. With the increase of layer number, the hardness of welding pieces decreases gradually. When welding piece is lower than eight layers, the rise of width and height of the welding piece is approximately proportional to the increase of layers. Those conclusions of this paper provide general guidance and technical support for the repairing of cast iron cylinder heads and welding of other cast iron parts.

Spreading Corrosion-Model of Self-Potential Methods, Case Study of Buried Metal Laboratory Scale

Self-potential is a geophysical method as an inexpensive, practical, and simply used measurements. Measuring with this as simply used, make it’s become sensitive to noise and causing difficulties with interpretation. As an environment geophysical method, self-potential would give a good interpretational model. One other way to getting a good model to reduced the noise data. The noise reduction developed by making the experiment box model as the only exploration field. Experiment box model is formed by composing paving blocks at the edge of the box. The purpose of the experiment is to analyze the target, which is a massive iron cylinder, as a physical and chemical reaction. The iron placed in the sandbox which has two conditions, half-down wet and half-up dry. The porous pot made from mini straw which is appropriated with the sandbox dimension and target experiment. The experiment took five weeks as periodically measurement.The results were potential graphics and two-dimension iso-potential maps. Existing of iron-related to large-amplitude potential anomalies around the target. Thus, corrosion-related to compared periodical-maps of anomaly contour area. The difference of anomaly’s pattern in the last two maps might cause the internal changed of the box model. This experiment indicated that self-potential signals can be used to monitor corrosion processes.

Comparative Experimental Study of Tribo-Mechanical Performance of Low-Temperature PVD Based TiN Coated PRCL Systems for Diesel Engine

Piston ring and cylinder liner (PRCL) interface is a major contributor to the overall frictional and wear losses in an IC engine. Physical vapor deposition (PVD) based ceramic coatings on liners and rings are being investigated to address these issues. High temperature requirements for applications of conventional coating systems compromise the mechanical properties of the substrate materials. In the current study, experimental investigation of tribo-mechanical properties is conducted for various titanium nitride (TiN) coated PRCL interfaces in comparison with a commercial PRCL system. Low-temperature PVD based TiN coating is successfully achieved on the grey cast iron cylinder liner samples. Surface roughness of the grey cast iron cylinder liner substrates and the thickness of TiN coating are varied. A comprehensive comparative analysis of various PRCL interfaces is presented and all the trade-offs between various mechanical and tribological performance parameters are summarized. Coating thickness between 5 and 6 micrometres reports best tribo-mechanical behaviour. Adhesion and hardness are found to be superior for the TiN coatings deposited on cylinder liner samples with higher roughness, i.e., ~ 5-micron Ra. Maximum 62 % savings on the COF is reported for a particular PRCL system. Maximum 97% saving in cylinder liner wear rate is reported for another PRCL system.

Influence of steadite on the tribological behavior of cylinder liners

PurposeThis paper aims to understand the effect of steadite in gray cast iron (GCI) cylinder liners performance (friction and wear) when lubricated with new lube oil formulations to verify if steadite can be reduced or suppressed from cylinder liners composition.Design/methodology/approachThe paper presents an experimental approach to quantify the separated effect of lube additives and steadite content on GCI performance. Friction and wear of GCI samples with and without steadite were analyzed under lubricated conditions with a 5W30 lubricant and a base oil of similar viscosity under operating conditions similar to the ones observed at the top dead center of Otto engines. Scanning electron microscopy (SEM)-EDS analysis was used to evaluate wear and tribofilm formation.FindingsThe paper shows that steadite stabilizes friction coefficient and slightly reduces wear in the tests performed with base oil. However, its advantages are marginal in comparison to the ones provided by the fully formulated oil. Furthermore, SEM-EDS analyses of the wear track showed that steadite does not chemically react with zinc and sulfur compounds, reducing the tribofilm formation on the real area of contact and consequently changing the tribosystem behavior.Originality/valueThis paper covers an identified need to study the effect of lube additives and GCI composition using actual piston ring and cylinder liners under operating conditions similar to the ones observed at the top dead center of Otto engines.

Antiproliferative properties of iron supramolecular cylinders

The use of metallohelicates as potential antiproliferative agents is mostly exemplified by one sole family of supramolecular compounds that is based on bis-iminopyridine ligands. In the present investigation, two other types of metallocylinders have been selected and their potential DNA-binding and cytotoxic properties have been investigated. Hence, two new neutral iron(III) metallosupramolecular compounds have been prepared from bis-β-diketone ligands, and a known cationic iron(II) helicate from bis-pyrazole ligands has been used for comparison purposes. DNA-interaction experiments and cell studies reveal remarkable biological properties for one of the neutral iron cylinders and the positively charged, pyrazole-based helicate, as illustrated by their antiproliferative behaviours, which are far better than those of two well-known compounds, i.e. the most studied metallohelicate in the field and cisplatin.

Reciprocating electrolyte jet with prefabricated-mask machining micro-dimple arrays on cast iron cylinder liner

Cast iron cylinder liner in the diesel engine is putting forward higher requirements on the tribological performance. The micro-texture machined on the cast iron cylinder liner surface has demonstrated the brilliant potential of friction reduction. However, the existing micro-texturing technologies of the cylinder liner have some limitations, such as the workpiece deformation, the low processing efficiency and the high cost of the machining equipment. In the paper, the reciprocating electrolyte jet with prefabricated-mask (REJP) machining technology was used to generate circular dimple arrays on the cast iron cylinder liner. The micro-machining equipment adopts the direct current power instead of the pulse power. The electrolyte jet as the cathode driven by the step-wise motor realizes the reciprocating movement. In addition, the arc shape of the cathode opening is identical with the cylinder liner to guarantee the same inter-electrode gap along the curved liner. After the electrolyte flows out of the cathode opening, three machining areas including the injected area by the vertical flow, the activated area and the wetted area by the horizontal flow, are formed on the cylinder liner surface by the prefabricated-mask. The circular dimple can be uniformly fabricated in arrays with the following optimized machining parameters: cathode velocity = 10 mm/s, electrolyte flow = 45 ml/s, applied voltage = 10 V, electrolysis time = 60 s. By using the prefabricated-mask with the array hole of 800 μm in diameter, the best dimension of micro-dimple is about 43 μm in depth and 822 μm in diameter. Compared with the non-dimpled cylinder liner, the friction coefficient of the micro-dimpled cylinder liner decreases as much as 12.0% under the heavy load of 20 MPa.

A Soft Retraction System for Surgery Based on Ferromagnetic Materials and Granular Jamming

In recent years, minimally invasive surgery (MIS) has gained wider acceptance among surgeons. MIS requires high skills for the operators, mainly due to its intrinsic technical limitations. Tissue manipulation and retraction remain the most challenging tasks; more specifically liver, stomach, and intestine are the organs mostly involved in retraction tasks for abdominal procedures. The literature reports an increasing interest toward dedicated solutions for abdominal tissue retraction tasks. To overcome the limitations of commercial systems and research prototypes, the aim of this study is the design, the realization, and the validation of a retraction system that is simple, reliable, easy to use, safe, and broadly compatible with MIS. The proposed retractor has two main components: (1) a soft central part with variable stiffness obtained by exploiting the granular jamming phenomenon for assuring, at the same time, safe introduction into the abdominal cavity and stable retraction and (2) two iron cylinders located at the two extremities of the device for anchoring the retractor to the abdominal wall by using the magnetic attraction force between these components and two external permanent magnets. System design has been performed by deeply investigating granular jamming principle and ferromagnetic properties of iron elements. Ex vivo and in vivo assessment has been carried out with the final aim to identify the most appropriate design of each retractor component and to demonstrate the advantages of using a soft system with variable stiffness during a retraction task.

Wear Properties and Scuffing Resistance of the Cr–Al2O3 Coated Piston Rings: The Effect of Convexity Position on Barrel Surface

This work investigates the effect of convexity position of ring barrel surface on the wear properties and scuffing resistance of the Cr–Al2O3 coated piston rings against with the CuNiCr cast iron cylinder liner. The scuffed surface morphology and elements distribution as well as the oil film edge were analyzed to explore the influencing mechanism of the convexity position on the scuffing resistance. The results show that the convexity offset rate on the barrel surface of the ring has no noticeable influence on both friction coefficient and wear loss near the dead points, but a suitable convexity position will result in the improved scuffing resistance. The shape of the barrel face not only affects the worn area on the ring, but also determines the oil film wedge and pressure distribution, consequently influences the scuffing resistance.