Brass Coated Steel Wire Research Articles

Enhancement of resource recovery from retired tires: Extraction of copper and zinc resources

The disposal of scrap rubber, represented by retired tires, has achieved industrial achievements, but the handling of brass-coated steel wire as a structural reinforcement in retired tires has received little attention. A feasible and efficient method of acquiring economical resources is proposed to extract copper and zinc (Cu-Zn) from brass-coated steel wire. With 20% ammonia, 10% hydrogen peroxide, and a liquid-solid ratio of 10, the brass coating almost completely dissolved in 5 minutes. This technique may remedy the challenge of weak dissolving efficiency brought on by the dual phase microstructure of brass. Electrochemical measurements and density functional theory (DFT) simulations assist in verifying that hydrogen peroxide decreases the resistance of the corrosion and that OH- and O-2 in solution are the main contributors to the dissolution. In addition, the AH effectively enhances the corrosion of the α phase in brass, which is notably evident in comparable works. This effective strategy broadens the application of retired tires and provides a new method for extracting Cu-Zn resources.

Importance of the surface and environmental conditions on the corrosion behavior of brass, steel and brass coated steel wires and brass coated steel cords

In tires, cords consist of brass coated wires. Even if they are embedded in rubber matrix, wires remain sensitive to corrosion. This work proposes an evaluation of the electrochemical reactivity of the constituents of the wire: the steel, the brass, and the brass coated steel. Tests were immersed in solutions where pH, solution convection, and oxidizing species were controlled. Results confirm the establishment of galvanic coupling between iron and brass. In aerated and neutral solution, the dissolve dioxygen reduction acts on the interfacial pH modifying the reactivity of the brass coated steel.

Identification of the Corrosion Mechanism of Brass-Coated Steel Wires in Cords Assembly

The corrosion behavior of brass-coated steel wire in cord assembly is discussed in this article. Experiments were performed on wires with different diameters and a cord composed of 19 wires. The open-circuit potential was recorded in a stagnant, aerated and neutral sulfate solution. Results showed a preferential initiation of the corrosion on morphological defects induced by the drawing. Moreover, the galvanic coupling between the brass layer and the steel led to the preferential dissolution of iron. For the cords, a crevice-like mechanism was identified. Inside the wire assembly, local acidification takes place because of the hydroxylation of iron ions. Lepidocrocite (γ-FeOOH) was detected by micro-Raman spectroscopy suggesting a pH of about 5 in the confined environment. At the external surface of the cord, both γ-FeOOH and Fe3O4 were identified. Their presence was attributed to the local variation of pH induced by a repartition of cathodic and anodic areas. Based on these results, a general scheme was proposed to illustrate the mechanism of corrosion of the cords.

Fundamental study on fine wire EDM characteristics using γ-phase brass coated steel wire

Fundamental study on fine wire EDM characteristics using γ-phase brass coated steel wire

Infrared thermometers for small wires drawing

This work describes the design of two contactless thermometers based respectively on a total radiance and two-color pyrometry scheme, developed to measure the temperature of a small brass coated steel wire during wire drawing. In this critical condition, wire oscillation and relevant insertion errors do not allow using commercial contact or contactless sensors. Thus, ad hoc pyrometers optical layouts have been designed in order to minimize sensitivity to the wire oscillations and emissivity changes. Moreover, performances associated to different infrared detectors have been compared using as figure of merit the achieved measurement uncertainty simulating typical disturbances, i.e. the background temperature variation, the slope of the wire’s emissivity and the effect of the atmosphere transmittance. Finally, the uncertainty budgets were drawn, evidencing the limitations of the proposed methods and identifying the best configuration for both developed instruments.

RUBBER–BRASS ADHESION LAYER ANALYSIS USING THE OLEFIN-METATHESIS METHOD

ABSTRACT The investigation of the adhesion layer between rubber and brass-coated steel wires is a challenging task due to its strong bonding. We explore the possibilities of olefin-metathesis as a method to degrade the cross-linked rubber network without destroying the adhesion layer. Using a ruthenium catalyst and 1-octene as a co-reactant, different types of rubber—natural rubber, acrylonitrile–butadiene rubber, and styrene–butadiene rubber—can be degraded into soluble fragments. The uncovered adhesion layers can be subsequently analyzed with common analytical methods such as optical microscopy, focusvariation microscopy, and scanning electron microscopy. The revealed surface structures are discussed considering the observed pull-out forces. In a second series, the influence of common additives—cobalt salt, silica, and a resin system—on the metathesis reaction is investigated.

Fundamental Study on Multi-wire EDM Slicing of SiC by Wire Electrode with Track-shaped Section

High efficient and precise slicing method is required for the slicing of silicon carbide ingot. The newly developed multi-wire electrical discharge slicing method would decrease the kerf width and the cracks generated on machined surface. However, much higher wire tension is required in order to reduce wire vibration and to perform a smaller kerf width. Thin wire electrode with round section does not have enough cross sectional area under the high wire tension condition. Therefore, a wire electrode with track- shaped section was proposed and applied to the wire EDM slicing of silicon carbide ingot. The running control of wire electrode with track-shaped section was experimentally investigated. The side support method with fixture plates could decrease the kerf width by brass coated steel wire electrode with track-shaped section. The parallel drawing type traverser and the short distance setting points of side support fixture plates could perform the smaller vibration of w ire electrode with track-shaped section and the decrease of kerf width.

Methodology for Measuring Trace Metal Surface Contamination on Pv Silicon Substrates

The production of high efficiency PV cells requires a strict control on metal contamination levels. Metals like Cu and Fe are well known to cause lifetime degradation in silicon. Analytical methodologies for determination of surface metal contamination have been well established for mirror polished, also referred to as chemical mechanical polished (CMP) silicon substrates [1]. It will be explained why these methods cannot be merely applied to photovoltaic (PV) wafers because of the large roughness and specific topography of the surface. Here we extend and adapt these analytical methodologies for surface metal contamination analysis on PV substrates also referred to as PV wafers. We demonstrate how vapour phase decomposition droplet collection (VPD-DC) in combination with total reflection X-ray fluorescence spectroscopy (TXRF) or inductively coupled plasma mass spectrometry (ICP-MS) has been modified to accommodate analysis on a non-polished PV silicon wafer surface. In addition we demonstrate how metal contamination on as-cut PV wafers has been determined by liquid surface etching (LSE), i.e. an oxidizing and slow etching solution used to dissolve metal contaminants, followed by TXRF analysis. Measurements of as-cut wafers shows the presence of Fe, Cu and Zn in very high concentrations (up to more than 1x1013at/cm2), residuals of the brass-coated steel wires used during wire sawing [10].

다이아몬드 연마재 입도가 초경 습식신선 다이스 수명에 미치는 영향

Wet wire drawing of brass coated steel wire, used for tire reinforcement, is realized with Tungsten Carbide(WC) dies sintered with a cobalt(Co) binder. Dies wear represents an important limitation to the production process and cost savings. Several parameters, such as Co content, WC grain size of tungsten carbide, sintering conditions, and so on, affect on the wear of the drawing die. In this study, the effect of the diamond abrasive particle size on the life of the WC centered dies of the wet wire drawing was investigated. Wet wire drawing experiments were carried out on a wet wire drawing machine. From the experiments, the dies life, dies fracture, wire surface roughness, and wire breaks were investigated. From the results, it was found that the wear of the WC dies increased with the increase in the diamond abrasive particle size.

Using ultra thin electrodes to produce micro-parts with wire-EDM

Small-sized tools and parts are gaining importance and share of the total product range Micromachining of Engineering Materials, 2002; Ann. CIRP 49 (2) (2000) 473]. An appropriate manufacturing process to cover the growing need for accurate small tools is electro-discharge-machining with thin wires (W-EDM). Until now only a few scientific works have been dealing with cutting by W-EDM using wires with a diameter below 50 μm. The results of the experiments with ultra thin wires are presented in this paper. The materials of the wires are tungsten with high tensile strength and melting temperature and brass-coated steel wire. Typical ultra thin wire diameters are 20, 25, 30 and 50 μm. The process forces—until now often neglected—are becoming significant because of the small tension forces on the wire and the low wire weight Single discharging force and single machining volume of wire EDM, ISEM XI, 1995]. A special set-up to use 20 and 25 μm wires with an existing machine which can run wires up to 30 μm was designed and constructed. Different wire types and diameters as well as electrical parameters were tested in several series of experiments. The process forces on the thin wires were measured with a special measuring device. The measuring sensor was positioned at the place where the discharges take place and was electrically isolated in order to prevent measuring interference. The single discharge craters were investigated on the workpiece surface. An electrical circuit was adapted onto the machine in order to allow just one single discharge to occur. The craters were located on the pre-ground workpiece surface and their dimensions were measured with an optical microscope.

Using ultra thin electrodes to produce micro-parts with wire-EDM

Small-sized tools and parts are gaining importance and share of the total product range [1], [2]]. An appropriate manufacturing process to cover the growing need for accurate small tools is electro-discharge-machining with thin wires (W-EDM). Until now only a few scientific works have been dealing with cutting by W-EDM using wires with a diameter below 50 μm. The results of the experiments with ultra thin wires are presented in this paper. The materials of the wires are tungsten with high tensile strength and melting temperature and brass-coated steel wire. Typical ultra thin wire diameters are 20, 25, 30 and 50 μm. The process forces—until now often neglected—are becoming significant because of the small tension forces on the wire and the low wire weight Single discharging force and single machining volume of wire EDM, ISEM XI, 1995]. A special set-up to use 20 and 25 μm wires with an existing machine which can run wires up to 30 μm was designed and constructed. Different wire types and diameters as well as electrical parameters were tested in several series of experiments. The process forces on the thin wires were measured with a special measuring device. The measuring sensor was positioned at the place where the discharges take place and was electrically isolated in order to prevent measuring interference. The single discharge craters were investigated on the workpiece surface. An electrical circuit was adapted onto the machine in order to allow just one single discharge to occur. The craters were located on the pre-ground workpiece surface and their dimensions were measured with an optical microscope.

Wear mechanism of tungsten carbide dies during wet drawing of steel tyre cords

Wet drawing of brass coated steel wires, used for tyre reinforcement, is realised with tungsten carbide (WC) dies sintered with a cobalt binder. Die wear represents an important limitation to the production process and cost savings. Mechanical models of drawing are not sufficient to explain the phenomenon experimentally observed. Experiments were carried out on an analytical drawing machine and coupled with SEM/EDX observations on cut half dies. Wear scars observed, correspond to brittle fractures and removal of grain clusters. Evidence of the existence of a metal transfer is given. It is composed of brass and iron whose presence is associated with die wear. Welding between iron and cobalt at high temperature modifies the binder, weakens the structure and leads to decohesion of grains and grain clusters. Two parameters play a major role on this mechanism. The iron transferred on the die surface and the thermal conditions, generated by both friction and plastic deformation, which accelerate wear. To prevent this decohesion wear, the lubricant must generate thick films to avoid asperity contacts, or extreme-pressure films to provide against iron/cobalt adhesion. Solutions like new die materials also represent an interesting option.

An investigation on the corrosion of brass-coated steel cords for tyres by electrochemical techniques

The electrochemical behaviour of brass-coated steel cord and brass-coated steel wire in a 0.25 M Na 2SO 4 solution has been studied by variation of the corrosion potential with immersion time in the aggressive solution and by determination of current–voltage curves and electrochemical impedance measurements. A corrosion mechanism of brass-coated steel wires that relies on a zinc depletion process of the brass coating and on the development of a copper oxide film over the zinc-depleted brass layer has been proposed in agreement with surface analyses (photoelectrons spectroscopy). The cord appears to be more resistant to corrosion than the wire. The hypothesis has been put forth that the zinc depletion process starts later and advances at a lower rate in the cord than in the wire. As far as the electrochemical techniques are concerned, electrochemical impedance spectroscopy allows the corrosion resistance of the two systems to be evaluated.

A Review of Polymer Interfaces in Tyre Technology

AbstractThe study of polymer interfaces is of prime importance in the field of tyre technology due to the critical role these contribute to tyre operation. The paper reviews the main polymer interfaces present in a tyre—(1) tyre/road (tyre wear or abrasion; tyre traction/skid resistance); (2) polymer/filler (carbon black; silica); (3) polymer/cord (brass coated steel wire; textile—rayon, nylon, polyester, aramid); (4) compound/compound (tack); (5) tyre/air (oxygen/ozone protection)—with respect to the criteria required, physical and chemical, to achieve optimum performance.

Rubber cure: Accelerating agents as inhibitors of steel corrosion

Radial tires are structured with cords of brass-coated steel wires. The parameters that define the quality of the product are resistance to corrosion and adhesion to rubber after cure. The most widely used accelerating agents are reported together with their principal chemical-physical characteristics. The paper reports results related to the inhibiting properties which these molecules have on corrosion of steel. If the acid solution has been pre-saturated and the steel pre-immersed for 24 hours, the superficial film is stable and its protective efficiency reaches high values.

Surface composition, oxidation and sulfidation of cold-worked brass and brass-coated steel wire as studied by x-ray photoelectron spectroscopy I. Surface composition of commercial cold-worked brass

The surface composition of cold-worked Cu/Zn ( 64 36 ) alloy specimens following various mechanical, chemical, electrochemical or thermal treatments has been studied by X-ray photoelectron spectroscopy. Freshly polished brass shows a surface composition of 40% Cu due to the formation of a thin zinc-rich oxide layer. Storage at elevated temperatures increases the zinc oxide layer thickness, eventually resulting in an oxide layer which is devoid of copper. Dissolution of zinc from the outermost surface layers by electrochemical polishing or bright dipping results in a copper-rich surface. Heating of these samples at 300 °C forms an oxide layer rich in CuO. Generally however, copper is not oxidized in the presence of metallic zinc. The oxide film on brass, interpreted as a defect structure of ZnO, contains Cu and Zn atoms which can diffuse to the surface, where the zinc atoms are preferentially oxidized.