Morphology and Properties of Zn-Al-TiO2 Composite on Mild Steel

The influence of TiO2 composite and dispersed pure Al particle on zinc alloy electrodeposited on mild steel was studied from chloride bath solution.Microstructural and mechanical properties of the alloy were investigated. The structure, surface morphology, and surface topography of the deposited alloys were characterized by scanning electron microscopy (SEM) and atomic force microscope (AFM).In addition, hardness of the coated alloys was measured. It was found that the obtained Zn-Al-TiO2 alloyexhibited more preferred surface morphology and mechanical strength compared tothe substrate. The result shows the existence of interaction between TiO2 compounds and zinc alloy particulate. It also exhibited well bright dominate zinc coating on steel surface

Electrochemical and Mechanical Properties of Mild Steel Electro-plated with Zn-Al.

Surface enhancement of engineering materials is necessary for preventing service failure and corrosion attack in the industries. Deposition was performed to obtain a better surface adherent coating using electroplating technique. Zn-Al film was developed with zinc and aluminum powder particles dissolved in nitric acid and sodium hydroxide respectively, to form solutions containing Zn2+ and Al3+ ions. Anomalous co-deposition on mild steel resulted into surface modification attributed to the complex alloys that was developed. The effect of deposition potential was systematically studied using Focused-ion beam scanning electron microscope (FIB-SEM), Atomic force microscope (AFM), X-ray diffraction (XRD) and Fourier transform infra-red (FTIR). Thick, adherent, smooth and uniform Zn-Al coating was deposited with relatively high deposition rate of 1.0 V. Experimental results indicated that the introduction of Al into the coating does significantly alter the chemical and mechanical properties of the mild steel. The microhardness value was increased by 92%; wear rate was decreased by 90% and a significant increase in the corrosion resistance was achieved based on the formation of stable deposited particles of Zn-Al

Comparative Studies of Microstructural, Tribological and Corrosion Properties of Plated Zn and Zn-alloy Coatings

Difficulties in choosing appropriate material(s) for a particular application and the control of environmental menaces cannot be over emphasized. Films of Zn and Zn–Al were electrodeposited on mild steel substrates using Zn and Zn–Al alloy plating solutions respectively. Focus ion beam scanning electron microscope (FIB-SEM) images and Atomic force microscope (AFM) were used to study the surface morphology, the topography and the surface adherent properties of the coatings. The elemental composition and the phases evolved in composite coatings were measured by means of X-ray diffractometer (XRD) and energy dispersive spectrometer (EDS). The cyclic voltammetry techniques were used to explain deposition process. The microhardness measurements and the electrochemical and wear behaviours of the deposits were investigated. Experimental results showed that Zn-Al coatings had homogeneous distribution of the fine particles deposited. These coatings had higher corrosion and wear resistances over the Zn deposited coatings as well as the substrate

Suitability of local binder compositional variation on silica sand for foundry core-making

The use of local oils, namely groundnut oil, cotton seed oil and palm oil with Nigeria local clay and silica sand for the production of foundry cores has been investigated on varying composition. Addition of cassava starch, local clay, oil and moisture to sand are used to produce strong and efficient core. These oils were tested and it was found that the three could be used to produce foundry cores. The best composition was found to be core comprising 2.5% starch, 2.5% clay, 8% oil, 8% moisture and 68% sand and baked at 150oC for 1 h 30min. The tensile strength of the core were as high as 600 KN/m2

Experimental study of ZrB2-Si3N4on the microstructure, mechanicaland electrical properties of high grade AA8011 metal matrixcomposites

The present study evaluates the hybrid effect of ZrB2-Si3N4on the properties of AA8011 metal matrixcomposites (AMMCs) developed by two steps stir casting process. The percentage of reinforcement variesfrom 0% to 20% weight. The microstructure, hardness, ultimate tensile strength, yield strength, electricalresistivity, and conductivity were examined. From the results, it was revealed that the mechanicalproperties of the reinforced alloy are well improved compared to the unreinforced alloy. The opticalmicrograph and the scanning electron micrograph images with energy dispersive spectroscopy show theuniform distribution of the hybrid particulates of ZrB2-Si3N4with no visible porosity. The electrical re-sistivity of the developed AA8011 composites was also improved with the increase in weight percent ofthe ceramic particulates, but the electrical conductivity was drastically reduce

Physio-Chemical and Mechanical Behaviour of(Pinussylvestris) as Binders on Foundry Core Strength

The mechanical potential of sand core binders made withPinussylvestris has been examined. Ota silica base sand bonded with 6% of cassava starch in admixed proportion of Pinussylvestris was tested for tensile, compressive strength and permeability to establish the binding efficiency. Tensile strength of the green baked core were oven baked at 50°C, 100°C, 150°C and 200°C.The cylindrically shaped permeability specimens were tested with permeability meter. Study revealed thatPinussylvestris showed an improve properties at 6% cassava starch at 200°C

Corrosion Polarization Behaviour of Type 316 Stainless Steel in Strong Acids and Acid Chlorides

The corrosion resistance and/or susceptibility of Type 316 austenitic stainless steel was separately performed at ambient temperature in different concentrations (the intermediate and the concentrated) of sulphuric acid, H2SO4, and phosphoric acid, H3PO4. Similar tests were also performed by the addition of 2% (20g/l) sodium chloride, NaCl, to each of the specified acid concentrations to form their acid chlorides. Potentiostatic polarization method was used for the corrosion investigation. The electrochemical corrosion reactions exhibited both the passive and active corrosion reactions characteristics. The acids at the intermediate concentrations show more obvious active corrosion reactions; while in the concentrated form they were relatively passive – the passivity that was associated with the oxidizing nature of the concentrated acids. The addition of 2% NaCl to each of the test medium concentration gave increased active corrosion reactions that could be due to the test electrodes’ surface protective film rupture by anodic dissolution. In all the tests, however, the magnitude of corrosion could be considered to be lo

An Investigation of the Properties of Zn Coated Mild Steel

Researches in the area of zinc coatings on steel are rather unending because of the unique properties and the very low cost that it offers. In this paper, the mechanical (wear and hardness) and corrosion behaviours of Zn Coated Mild Steel in 3.65% NaCl are described. A thin film of Zn on steel substrates was prepared by electrodeposition technique using Zn particles to form a bath plating solution. Scanning electron microscope and Atomic force microscope were used to study the surface morphology, the topography and the surface adherent properties of the coatings. The crystal particles present were observed by X-ray diffraction pattern (XRD) and energy dispersive X-ray diffraction spectrometer (EDS). The microhardness of deposited plate, the electrochemical behavior and the corrosion properties of the deposits were investigated by means of Vickers microhardness and polarization measurements. The uniform deposits of Zn showed fine grains and good protection against corrosion as appreciated 75% hardness value was achieved

Effect of some process variables on zinc coated low carbon steel substrates

This work investigates the effect of some essential plating variable of zinc electro-deposition on low carbon steel substrates. The variation of plating parameter, the depth of immersion, distance between the anode and the cathode on voltage, plating time and coating thickness was considered. The steel substrates were immersed into solution of zinc electroplating bath for varying voltage between 0.5 and 1.0 V. It was discovered that the sample plated at 0.8 V for 20 min gave the best plating properties and it was also observed that increase in applied voltage, plating time, depth of immersion and decrease in distance of the object (cathode) from the anode increases weight gained. Microstructural studies with SEM/OPM however, revealed fine grained deposit of the deposited zinc and the inclusion of addition agent

Anti-Corrosion and Tribo-Mechanical Properties of Co-deposited Zn–SnO2 Composite Coating

Zn–SnO2 composite coatings were prepared by direct potential using electrolytic co-deposition technique from sulfate solution. The effect of Zn2? and SnO2 concentrations in deposited bath on the mechanical properties and morphological characteristics of the composite coatings were examined. The characterizations of the sample were analyzed using scanning electron microscopy couple with energy dispersive spectroscopy (SEM/EDS), X-ray diffraction (XRD) and atomic force microscopy (AFM). The electrochemical degradation behavior of the samples in 3.65 wt.% NaCl solution was studied using potentiodynamic polarization technique and characterized by high-resolution optical microscope. From all the fabricated composite coatings, obvious diffraction peaks were observed with Zn-7Sn-S-0.3V film with Zn2Sn7, Sn, Zn2Sn5 and Zn phases, confirming the presence and formation of Zn–SnO2 coating. The XRD pattern shows that the presences of SnO2 particle remarkably play a major role in the precipitation and orientation of the alloy matrix. From the SEM/EDS and AFM results, the deposits show that composite particle and proper bath composition have strong influence on the microstructure. An enhanced corrosion resistance was attained as a result of the induced particles