Effect of ultra-disperse powder in electrode coating on properties of welds in MMA welding

In this review, the unique properties of intrinsically conducting polymer (ICP) in biomedical engineering fields are summarized. Polythiophene and its valuable derivatives are known as potent materials that can broadly be applied in biosensors, DNA, and gene delivery applications. Moreover, this material plays a basic role in curing and promoting anti-HIV drugs. Some of the thiophene’s derivatives were chosen for different experiments and investigations to study their behavior and effects while binding with different materials and establishing new compounds. Many methods were considered for electrode coating and the conversion of thiophene to different monomers to improve their functions and to use them for a new generation of novel medical usages. It is believed that polythiophenes and their derivatives can be used in the future as a substitute for many old-fashioned ways of creating chemical biosensors polymeric materials and also drugs with lower side effects yet having a more effective response. It can be noted that syncing biochemistry with biomedical engineering will lead to a new generation of science, especially one that involves high-efficiency polymers. Therefore, since polythiophene can be customized with many derivatives, some of the novel combinations are covered in this review.

The bimetallic welds are frequently utilized for pipeline transport system of the nuclear power plants. The occurrences of welding defects generally depend on the filler electrode as well as the electrode coatings during shielded metal arc welding process. This study involves the design of austenitic stainless steel welding electrodes for SS304L–SA516 bimetallic welds. The objective of research work includes the novel design of Al2O3–TiO2–CaO–SiO2 coatings by combining two ternary phase systems using extreme vertices mixture design methodology to analyze the effect of key coating constituents on the weld metal chemistry and mechanical properties of the welds. The significant effect of electrode coating constituent CaO on weld metal manganese content is observed which further improves the toughness of bimetallic weld joints. Various regression models have been developed for the weld responses and multi objective optimisation approach using composite desirability function has been adopted for identifying the optimized set of electrode coating compositions. The role of delta ferrite content in promoting the favourable solidification mode has been studied through microstructural examination.

This work investigates the microstructure and mechanical properties of 2507 super duplex stainless steel and API X70 high strength low alloy steel weld joint. This joint finds application in offshore hydrocarbon drilling riser and oil–gas pipelines. Coated shielded metal arc welding electrodes have been designed and extruded on 309L filler and their performance compared with a commercial austenitic electrode E309L. Filler 309L solidifies in ferrite-austenite (F-A) mode with a resultant microstructure comprising skeletal ferrites with austenite distributed in the interdendritic region. Results of tensile and impact tests indicate that weld fabricated with laboratory-developed electrodes has higher ductility and impact energy than the commercial electrode. The tensile strength and weld hardness of commercial electrodes are superior. The laboratory-made electrode’s microhardness is lower than the commercial electrodes, making the former less prone to failure. An alternative welding electrode coating composition has been suggested through this work and found to be performing satisfactorily and comparable to the commercially available electrodes.

AbstractThe fundamental parameters method (FPM) enables one to determine with high accuracy the chemical composition of homogeneous samples, having only one reference sample. However, the reference sample composition should be similar to that of the samples analyzed.The x-ray fluorescence analysis of multicomponent heterogeneous materials (ores, minerals, their mixtures, welding electrode coating mixtures, fluxes, etc.) is made by the Δμ-correction method based on the combined use of the fundamental and empirical correlations maintaining all the advantages of the FPM. Sample composition is calculated on the basis of the element intensities measured in the sample and in the reference specimen and is corrected for the disturbing effect of excitation conditions and heterogeneity as well as the calculated values of one of the fundamental parameters (μ1). At the preliminary stage of calibration, the coefficients are determined using regression and the absolute fundamental expression for the element fluorescence intensity.

AbstractAlthough typical electrochemical double-layer capacitors (EDLCs) operate with aqueous or lithium-free organic electrolytes optimized for activated carbon electrodes, there is interest in EDLCs with lithium-ion electrolyte for applications of lithium ion capacitors and hybridized battery-supercapacitor devices. We present an experimental study of symmetric EDLCs with electrolyte 1 M LiPF6 in EC:EMC 50:50 v/v and electrode coatings with 5 wt% SBR or PEDOT:PSS binder at 5 or 10 wt% concentration, where for the PEDOT:PSS containing electrodes pseudocapacitance effects were investigated in the lithium-ion electrolyte. Two different electrode coating fabrication methods were explored, doctor blade coating and spraying. It was found that EDLCs with electrodes with either binder had a stability window of 0–2 V in the lithium-ion electrolyte. EDLCs with electrodes with 10 wt% PEDOT:PSS binder yielded cyclic voltammograms with pseudocapacitance features indicating surface redox pseudocapacitance in the doctor blade coated electrodes, and intercalation and redox phenomena for the sprayed electrodes. The highest energy density in discharge was exhibited by the EDLC with doctor blade-coated electrodes and 10 wt% PEDOT:PSS binder, which combined good capacitive features with surface redox pseudocapacitance. In general, EDLCs with sprayed electrodes reached higher power density than doctor blade coated electrodes. Graphic abstract