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

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

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

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

Performance Evaluation of Zinc Deposited Mild Steel in Chloride Medium.

The effect of deposited mild steel under plating variable influence was investigated in a chloride medium. The results showed homogeneous layer with improved surface adhesion after deposition. The distance between the anode and the cathode on voltage, plating time and coating thickness were observed. The mild steel was deposited into solution of zinc bath for varying voltage between 0.6 v and 1.0v. It was discovered that the sample plated at 1.0v for 15 minutes gives the best plating surface finish. Analytical study using potentiastat/galvanostat, focused ion beam scanning electron microscopy (FIB-SEM), XRD and AFM were used to determine the surface characterization, topography and corrosion evaluation of the substrat

ZnO as corrosion inhibitor for dissolution of zinc electrodeposited mild steel in varying HCl concentration

The corrosion behavior of Zn electrodeposition on mild steel in varying 0.1 to 0.5 M of HCl with and without inhibitor was studied using weight loss measurement and optical microscope. The (OP) results revealed that the corrosion mechanism layers of the zinc plated mild steel without inhibitor has high content corrosivity related to the appearance of cracks due to the dissolution into the acidic medium. However, the zinc electrodeposition with ZnO as an inhibitor in the test medium shows a stable layer formation. The Zn coatings were found to contain an insoluble corrosion products, which act as a corrosion barrier that prevent corrosion from been attacked by the hydrogen presence

In-situ Behaviour of Selected Local Sand Binders on Microstructure and Mechanical Properties of Grey Cast Iron

The need to develop local sand binder by manufacturing industries has become necessary for national development. In this paper, the suitability of selected local sand binders on microstructural and mechanical properties of sand cast-grey cast iron was examined. The bentonite, cassava starch, rubber latex is varied for 5w% - 11w% fritter added to 100% silica sand of 5w% water. The selected scrap was superheated to 1550oC with 0.1% (Fe-Si) inoculant for proper dissolution. The microhardness and tensile properties were examined using Brinnel hardness (HBN) and Instron Tensiometer (1195) for tensile values (MPa) respectively. The microstructural properties of the produced cast were examined through Nikon metallurgical microscope. Results obtained from the grey cast revealed a pearlite matrix interface, massive carbide and graphite phases. Molds bonded with bentonite and cassava starch appears better with average hardness value of 437 and 385 (HBN) respectively. The microstructure was seen to be dominated by majorly pearlite matrix with little carbide which are favorable for the formation of gray cast iron which requires low chilling in the moul

Study of Al2O3/SiC particle loading on the microstructural strengthening characteristics of ZneAl2O3eSiC matrix composite coating

In this paper, the microstructure, and mechanical performance of ZneAl2O3eSiC film codeposited on mild steel substrate were produced by electrodeposition method. The structural characteristic of the composite coating was analyzed by scanning electron microscope (SEM) equipped with energy dispersive spectrometer (EDS), X-ray diffraction (XRD) and atomic force microscope (AFM). Mechanical examination was done using durascan hardness tester. The result showed that the influence of individual particle loading greatly alter the structural properties and hardness behavior. The increase in hardness is attributed to the perfect homogeneity and characteristics of the particulate which led to the formation of uniform distribution, coherent and interfacial precipitation within the zinc lattice