Search results
1 – 10 of over 1000M.N. Masri, Z.M. Yunus, A.R.M. Warikh and A.A. Mohamad
The purpose of this paper is to investigate the electrical conductivity and corrosion protection properties of a conductive coating composed of epoxy resin and carbon black in a…
Abstract
Purpose
The purpose of this paper is to investigate the electrical conductivity and corrosion protection properties of a conductive coating composed of epoxy resin and carbon black in a sodium chloride (NaCl) solution.
Design/methodology/approach
The conductive coating was prepared by combining epoxy resin, hardener, and carbon black. The electrical conductivity of the paint was studied with a DC current‐voltage meter and field emission scanning electron microscopy. The corrosion protection properties of the paint were characterized by open circuit potential measurements and electrochemical impedance spectroscopy.
Findings
The highest conductivity observed was 4.23×10−4 Scm−1 for the coating containing 20 wt% carbon black. The coating protected mild steel in a 3.0 percent NaCl solution for up to five days.
Originality/value
The results shown in this paper provide an insight into conductive paint and corrosion protection for future industrial applications and development.
Details
Keywords
Deyu Wu, Ding Wang, Daliang Yang, Ye Jinhua and Haibin Wu
The tactile sensor with array structure normally has the defects of existing nondetection zone, complex and nonstretchable structure. It is difficult to seamlessly attach to the…
Abstract
Purpose
The tactile sensor with array structure normally has the defects of existing nondetection zone, complex and nonstretchable structure. It is difficult to seamlessly attach to the surface of the robot. For this reason, this paper proposes a method to prepare nonarray structure tactile sensor directly on the surface of the robot by spraying process.
Design/methodology/approach
Based on the principle of gradient potential distribution, the potential fields are constructed in two different directions over the conductive film in time-sharing. The potentials at touching position in the two directions are detected to determine the coordinate of the touching point. The designed tactile sensor based on this principle consists of only three layers. Its bottom layer is designed as a weak conductive film made of graphite coating and used to construct the potential field. It can be sprayed either on PET substrate or directly on robot surface.
Findings
The radial basis function neural network is used for remodeling the potential distribution, which can effectively solve the problem of nonlinear potential distribution caused by irregular sensor shape, and uneven conductivity at different points of the spraying coating. The simulation and experimental results show that the principle of the proposed tactile sensor used for touching position detection is feasible to be applied to complex surfaces of the robot.
Originality/value
This paper proposed a nonarray customizable tactile sensor based on the spraying process. The sensor has a simple structure, and only five lead wires are needed to realize the coordinate detection of the touch position.
Details
Keywords
The paint industry is always intrigued by speciality coatings. Literally thousands of paint formulations have been devised over the years with highly specialized and very…
Abstract
The paint industry is always intrigued by speciality coatings. Literally thousands of paint formulations have been devised over the years with highly specialized and very frequently intriguing functions. In this latter category is a process described in Japanese patent 19,790 (1971) for painting polka dots upon sheet metal. How often the need for such technology might arise in the life of the average paint chemist is, of course, a moot question. But some comfort can no doubt be drawn from the fact that this unique methodology exists!
Haiqiang Yu, Quanzhong Guo, Keqin Du, Dongyun Li, Chuan Wang and Yong Wang
The purpose of this paper is to investigate the interfacial conductivity and corrosion resistance of the Ni–P/Ti4O7 composite coating that is deposited on a carbon steel substrate…
Abstract
Purpose
The purpose of this paper is to investigate the interfacial conductivity and corrosion resistance of the Ni–P/Ti4O7 composite coating that is deposited on a carbon steel substrate as bipolar plates for proton exchange membrane fuel cells.
Design/methodology/approach
The Ni–P/Ti4O7 coating was prepared by electroless plating. Scanning electron microscopy, white light interference, energy dispersive spectrometry and X-ray diffraction were used, respectively, to study the surface morphology, chemical composition and phase composition of coated samples. Electrochemical impedance spectroscopy, potentiodynamic and potentiostatic polarization were used to test the electrochemical performance and corrosion behavior. The interfacial contact resistance (ICR) was measured via the standard method.
Findings
The surface of the Ni–P/Ti4O7 coating is complete and dense and without obvious defects. The electrochemical test results show that the Ni–P/Ti4O7 coating provides better corrosion resistance than the Ni–P coating and substrate. Compared with the Ni–P coating, the ICR of the Ni–P/Ti4O7 coating is lower by about 82.7%. This is because the coating has more conductive contact points. The more exciting thing is that the ICR of the Ni–P/Ti4O7 coating only increases to 12.38 mΩ·cm2 after 5 h of polarization.
Originality/value
This paper provides a method for achieving surface modification of metal bipolar plates. Introducing Ti4O7 particles in the Ni–P layer reduces the contact resistance before and after polarization while ensuring good corrosion resistance.
Details
Keywords
Rafiu King Raji, Xuhong Miao, Shu Zhang, Yutian Li, Ailan Wan and Charles Frimpong
The use of conductive yarns or wires to design and construct fabric-based strain sensors is a research area that is gaining much attention in recent years. This is based on a…
Abstract
Purpose
The use of conductive yarns or wires to design and construct fabric-based strain sensors is a research area that is gaining much attention in recent years. This is based on a profound theory that conductive yarns will have a variation in resistance if subjected to tension. What is not clear is to which types of conductive yarns are most suited to delivering the right sensitivity. The purpose of this paper is to look at strain sensors knitted with conductive composite and coated yarns which include core spun, blended, coated and commingled yarns. The conductive components are stainless steel and silver coating respectively with polyester as the nonconductive part. Using Stoll CMS 530 flat knitting machine, five samples each were knitted with the mentioned yarn categories using 1×1 rib structure. Sensitivity tests were carried out on the samples. Piezoresistive response of the samples reveals that yarns with heterogeneous external structures showed both an increase and a decrease in resistance, whereas those with homogenous structures responded linearly to stress. Stainless steel based yarns also had higher piezoresistive range compared to the silver-coated ones. However, comparing all the knitted samples, silver-coated yarn (SCY) proved to be more suitable for strain sensor as its response to tension was unidirectional with an appreciable range of change in resistance.
Design/methodology/approach
Conductive composite yarns, namely, core spun yarn (CSY1), core spun yarn (CSY2), silver-coated blended yarn (SCBY), staple fiber blended yarn (SFBY) and commingled yarn (CMY) were sourced based on specifications and used to knit strain sensor samples. Electro-mechanical properties were investigated by stretching on a fabric tensile machine to ascertain their suitability for a textile strain sensor.
Findings
In order to generate usable signal for a strain sensor for a conductive yarn, it must have persistent and consistent conductive links, both externally and internally. In the case of composite yarns such as SFBY, SCBY and CMY where there were no consistent alignment and inter-yarn contact, resistance change fluctuated. Among all six different types of yarns used, SCY presented the most suitable result as its response to tension was unidirectional with an appreciable range of change in resistance.
Originality/value
This is an original research carried out by the authors who studied the electro-mechanical properties of some composite conductive yarns that have not been studied before in textile strain sensor research. Detailed research methods, results and interpretation of the results have thus been presented.
Details
Keywords
Xinchao Zhang, Huanxia Zhang, Danni Pan, Wen Wu, Hui Ma, Jianda Cao and Jia Xu
This paper aims to determine whether application of graphene layers to cuprammonium filaments affords the latter with excellent mechanical properties and improves their electrical…
Abstract
Purpose
This paper aims to determine whether application of graphene layers to cuprammonium filaments affords the latter with excellent mechanical properties and improves their electrical properties. At the same time, a circuit model was established to explore the conductive mechanism of the filament. The actual model is used to verify the correctness of the model.
Design/methodology/approach
The cuprammonium filaments were desizing, the graphene oxide layer-by-layer sizing and reduction integration process by a continuous sizing machine. The electrical properties of mono- and multifilaments in the static condition, as well as the dynamic–mechanical properties of multifilaments, were analysed, and the related conductive mechanism of the filaments was deduced.
Findings
Cuprammonium filaments coated with graphene layers showed good electrical conductivity, and their volume resistance decreased to 4.35 O·cm with increasing number of graphene coats. The X-ray diffraction and thermogravimetric analysis results showed that the graphene layer treatment changed the crystallinity of the copperammonia filaments and improved the thermal stability of the filaments. In the dynamic case, filament resistance was calculated using the equivalent resistance model, and the fitting difference observed was small. This result confirmed the high fit of this circuit model.
Originality/value
Up to the knowledge from literature review, there are no reports on theoretical research on the relation between the electro-mechanical property and structure of conductive filaments.
Details
Keywords
W.H. Gühring and g Ing.
Non‐destructive coating thickness measurements The Eddy Current Methods One of the methods suitable for measuring non‐destructively the thickness of electrically non‐conductive…
Abstract
Non‐destructive coating thickness measurements The Eddy Current Methods One of the methods suitable for measuring non‐destructively the thickness of electrically non‐conductive coatings on conductive and, in general, non‐magnetic substrates is the eddy current method. Examples are anodic oxide films on aluminium (DIN 17611, 17612, 50984, BS 1615 and ASTM B 244) and coatings of dry varnish, plastic, rubber and enamel on aluminium, brass, copper and austenitic steel. Low‐conductivity metallic coatings (e.g. Cr) on high‐conductivity substrates such as aluminium, copper or brass can also be measured with an instrument of modified design.
Abstract
Purpose
Strain sensors have been widely used to measure the strain of the structure. However, the ordinary sensing elements are not suitable for measuring large deformation on an irregular surface, which limits their applications. Recently, flexible sensors have attracted extensive interest because they can overcome the shortage of the ordinary sensing elements. The paper aims to discuss this issue.
Design/methodology/approach
In this paper, the whole measurement process of strain sensing behavior and the dimension design of fle3xible strain sensing system use the macroscopic measurement method of material tensile test to accurately measure the resistance change with strain. Afterwards, combining electrical components, the flexible strain sensors are produced for two biomedical applications: the wearable data-collecting gloves and rehabilitation training system.
Findings
The results show that the developed conductive fabric can exhibit high sensitivity, large workable strain range (>50 percent) under simple and repeated tension and good stability. Both applications demonstrate that the polypyrrole-coated fabric sensor can successfully measure the large and repeat strain, capture the motion of body and display corresponding information almost in real time.
Originality/value
The limitation lies in the lack of a holistic strain sensing mechanism study, and the lack of a corresponding theoretical model to explain the experimental results.
Details
Keywords
The latest range of portable coating thickness gauges from Elcometer — the Model 250 — incorporates digital display. The instruments are claimed to be the only portable digital…
Abstract
The latest range of portable coating thickness gauges from Elcometer — the Model 250 — incorporates digital display. The instruments are claimed to be the only portable digital coating thickness gauges presently available for both ferrous and non ferrous substrates. Two models are available, the 250F for measuring non ferromagnetic coatings on a ferromagnetic base up to a maximum thickness of 1000 microns (0.04in.), and the 250N version for measuring non conductive coatings on a non ferrous conductive base up to 200 microns thick (0.008in.).
The number of new alkyd resin‐based coatings introduced decreases yearly. To be sure, alkyd resins are the most important vehicles used for solvent‐based paints. On the other…
Abstract
The number of new alkyd resin‐based coatings introduced decreases yearly. To be sure, alkyd resins are the most important vehicles used for solvent‐based paints. On the other hand, the technology is mature and the major variations in the products are those which must be made to accommodate needs of the user. For the most part, these do not lead to completely new types of compositions.