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

Effect of composite particulate reinforcement on the morphology, anti-corrosion and hardness properties of fabricated Zn-ZnO coatings

Co-deposition of zinc metal matrix with ZnO composite was fabricated from electrolytic chloride based coating consisting of 20-40g/L ZnO particle. The resulting composite coatings were characterized using high optic microscope (OPM). The corrosion resistance properties of Zn-ZnO composite coatings were measure using linear polarization in 3.5% NaCl solution. The variation of amount of ZnO %wt. inclusion of the composite on micro-hardness was investigated using dura scan diamond base micro-hardness tester. The results obtained indicate that the introduction of ZnO particles in the deposition bath obviously increase significantly the hardness properties. The increases in hardness value are attributed to the realization of coherent and even precipitate into the metal lattice. The corrosion polarization resistance also improved slightly as against the MS. It was found that addition of ZnO %wt support strengthening characteristics toward hardness improvement with slight enhancement in anti-corrosion properties

In-Situ Evaluation of the Degradable Carbon Influence for Industrial Waste Water Treatment

A photochemical investigation and synergetic blend for wastewater purification was carried out. Blends of different peels: Potato-, Apple and Pineapples-peals (PAP-peals) were impregnated with aqueous solutions of ZnCl2 following the variant of the incipient wetness method for activation of activated carbon (AC). Different concentrations were used to produce impregnation ratios. Activation was carried out in a tube furnace by heating to 70

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

Comparative study on the effect of NaNO2 in corrosion inhibition of micro-alloyed and API-5L X65 steels in E20 simulated FGE

may positively slow down corrosion rate, its concentration within the tested range of 0.2 – 1.0 g/L plays an insignificant role in improving the corrosion resistance of API-5L X65 and micro-alloyed steels. Morphological examination of both steels after immersion tests in the presence and absence of the inhibitor showed pitting corrosion mechanism. Furthermore, statistical analysis confirms with 90 % confidence, that there is no significant difference between the corrosion behaviour of the two steels in E20 SFGE with and without NaNO2 inhibitor. Highest protection of the metal surface was achieved at 62.63 % with 0.2 g/L NaNO2 for API-5L X65 in E20. in E20 SFGE with and without NaNO2 inhibitor. Highest protection of the metal surface was achieved at 62.63 % with 0.2 g/L NaNO2 for API-5L X65 in E20

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

Optimizing the defensive characteristics of mild steel via the electrodeposition of Znsingle bondSi3N4 reinforcing particles.

The effect of ZneSi3N4deposition prepared via direct electrolytic co-deposition on mild steel was studiedas a result its inherent vulnerability to corrosion in an aggressive environment and failure on theapplication of load. The experiment was conducted varying the mass concentration of silicon nitride(Si3N4) between 7 and 13 g at cell voltage of 0.3 and 0.5 V, at constant temperature of 45�C. The mor-phologies of the coated surfaces were characterized using high resolution Nikon Optical Microscope andScanning Electron Microscope (SEM) revealing that the particles of the ZneSi3N4were homogeneouslydispersed. The corrosion behaviour was studied using potentiodynamic polarization technique in 3.65%NaCl solution and the microhardness was examined using Brinell hardness testing technique. The resultof the corrosion experiment confirmed an improved corrosion resistance with a reduction in corrosionrate from 9.7425 mm/year to 0.10847 mm/year, maximum coating efficiency of 98.9%, maximum polar-ization resistance of 1555.3Uand a very low current density of 9.33�10�6A/cm2. The negative shift inthe Ecorrrevealed the cathodic protective nature of the coating. The microhardness was also found tohave increased from 137.9 HBN for the unmodified steel to a maximum value of 263.3 HBN for the0.5Zne13Si3N4coated steel representing 90.9% increment in hardness as a result of the matrix grainrefining and dispersion-strengthening ability of the incorporated Si3N4particle

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

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

Degradation Evaluation of Zinc m 2 M Hydrochloric Acid m the Presence of Bambusa bambos

Failure evaluation of zinc sample in 2 M hydrochloric acid solution in the presence of Bambusa bambos extract was conducted using the gasometric method. Zinc coupons, each measuring 2.5 by 1.5 em were completely immersed in uninhibited and inhibited test solutions containing extract quantities of 60, 100 140 and 180 mL at a temperature of 298 K for 20 minutes. The volumes of hydrogen gas data obtained during the experiment were documented and analyzed. Results showed that maximum inhibitor efficiency and lowest corrosion rate were obtained at extract quantities of 140 and 100 mL, respectively while corrosion rate reduction did not follow any particular trend. Frumkin isotherm best explained the extract-metal surface interaction adsorption mechanism. Once quantity of the extract is known, an expression for estimating corrosion rate values was also obtained. In addition, the surface analysis indicated that the rate of deterioration of the metal reduced as extract quantity increased to some extent and changed thereafter