Production of Cutting Tools from Recycled Steel with Palm Kernel Shell as Carbon Additives

Machining is an integral and indispensable part of production technology with cutting tool playing key roles in its operations. This work therefore developed cutting tool from scrapped crank shaft, connecting rod, alloy additives and palm kernel shell. These materials were chosen due to their hardness and availability. The scrapped crankshaft and rod (100 kg) containing 0.560 % carbon were charged into electric induction furnace with maximum temperature 3000oC. The composition of the charged materials was analyzed with the UV-VIS spectrometer before and after melting. In order to raise the carbon content of the melt to 0.65% target (HSS) and upgrade relevant elements, alloy additives were added. Annealing was the first treatment carried out in muffle treatment furnace at temperature at 900oC for 9 hrs then cooled to 300oC. The annealed materials were machined into 20 pieces of long (199 x 12 x 12 mm) and short (20x 12 x12 mm) sizes. Further treatments of hardening, normalizing and tempering were also carried out on the cutting tools. The tools were then carburized with pulverized carbon using 20 % Barium trioxocarbonate (V) as an energizer in a muffle treatment furnace. Each of the samples was soaked at temperature of 800oC, 850oC, 900oC and 950oC for 60, 90 and 120 minutes holding time. Microhardness and surface hardness of the tool were 47.9 and 76.8HR, while for control sample were 46.1 and 76.3HR respectively

EFFECTS OF CARBURIZATION ON MECHANICAL PROPERTIES OF RECYCLED STEEL WITH PERM KERNEL SHELL (PKS) AS CARBON ADDITIVES.

The prediction and control of wear is one of the most essential problems emerging in the design of cutting operations which has to be checked through local production. This work therefore studies the effects of carburization on mechanical properties of recycled steel with Perm Kernel Shell (PKS) as carbon additives. 40 pieces of recycled Steel tools were used for the project. The tools were carburized with 40 kg of pulverized carbon of Perm Kernel Shell using 30 % Barium trioxocarbonate (V) as an energizer in a muffle treatment furnace of about 1500oC. Each sample was held at temperature of 800oC, 850oC, 900oC and 950oC for 60, 90 and 120 minutes holding time. The performance evaluation of the tool was done by using the tools (carburized and un-carburized) to machining low and medium carbon work piece on the lathe machine and also measured its impact/toughness using impact tester. The results shown best cutting performances and toughness in carburized tool of higher impact/ toughness value of 24 J over control sample of 17 J. The result of the performance evaluation tests corroborated the higher qualities of the carburized cutting tool over un-carburized type

Electroplating of CdTe thin films from cadmium sulphate precursor and comparison of layers grown by 3-electrode and 2-electrode systems

Electrodeposition of CdTe thin films was carried out from the late 1970s using the cadmium sulphate precursor. The solar energy group at Sheffield Hallam University has carried out a comprehensive study of CdTe thin films electroplated using cadmium sulfate, cadmium nitrate and cadmium chloride precursors, in order to select the best electrolyte. Some of these results have been published elsewhere, and this manuscript presents the summary of the results obtained on CdTe layers grown from cadmium sulphate precursor. In addition, this research program has been exploring the ways of eliminating the reference electrode, since this is a possible source of detrimental impurities, such as K+ and Ag+ for CdS/CdTe solar cells. This paper compares the results obtained from CdTe layers grown by three-electrode (3E) and two-electrode (2E) systems for their material properties and performance in CdS/CdTe devices. Thin films were characterized using a wide range of analytical techniques for their structural, morphological, optical and electrical properties. These layers have also been used in device structures; glass/FTO/CdS/CdTe/Au and CdTe from both methods have produced solar cells to date with efficiencies in the region of 5%–13%. Comprehensive work carried out to date produced comparable and superior devices fabricated from materials grown using 2E system

Growth of n- and p-type ZnTe semiconductors by intrinsic doping

Using intrinsic doping, n- and p-type ZnTe thin films have been electrodeposited (ED) on glass/fluorine-doped tin oxide (FTO) conducting substrate in aqueous solutions of ZnSO4·7H2O and TeO2. The intrinsic doping was achieved by simply varying the deposition potential. The films have been characterised for their structural, optical, electrical, morphological and compositional properties using X-ray diffraction (XRD), optical absorption, photoelectrochemical (PEC) cell measurements, scanning electron microscopy and energy-dispersive X-ray analysis techniques, respectively. The XRD results reveal that the electroplated films are polycrystalline and have hexagonal crystal structures. Optical absorption measurements have been used for the bandgap determination of as-deposited and heat-treated ZnTe layers. The bandgap of the as-deposited ZnTe films are in the range (1.70–2.60) eV depending on the deposition potential. PEC cell measurements reveal that the ED-ZnTe films have both n- and p-type electrical conductivity. Using the n- and p-type ZnTe layers, a p-n homo-junction diode with device structure of glass/FTO/n-ZnTe/p-ZnTe/Au was fabricated. The fabricated diode showed rectification factor of 102, ideality factor of 2.58 and threshold voltage of ~0.25 V

Electro-Plating and Characterisation of CdTe Thin Films Using CdCl2 as the Cadmium Source

Cadmium telluride (CdTe) thin films have been successfully prepared from an aqueous electrolyte bath containing cadmium chloride (CdCl2)·H2O and tellurium dioxide (TeO2) using an electrodeposition technique. The structural, electrical, morphological and optical properties of these thin films have been characterised using X-ray diffraction (XRD), Raman spectroscopy, optical profilometry, DC current-voltage (I-V) measurements, photoelectrochemical (PEC) cell measurement, scanning electron microscopy (SEM), atomic force microscopy (AFM) and UV-Vis spectrophotometry. It is observed that the best cathodic potential is 698 mV with respect to standard calomel electrode (SCE) in a three electrode system. Structural analysis using XRD shows polycrystalline crystal structure in the as-deposited CdTe thin films and the peaks intensity increase after CdCl2 treatment. PEC cell measurements show the possibility of growing p-, i- and n-type CdTe layers by varying the growth potential during electrodeposition. The electrical resistivity of the as-deposited layers are in the order of 104 Ω·cm. SEM and AFM show that the CdCl2 treated samples are more roughness and have larger grain size when compared to CdTe grown by CdSO4 precursor. Results obtained from the optical absorption reveal that the bandgap of as-deposited CdTe (1.48–1.52) eV reduce to (1.45–1.49) eV after CdCl2 treatment. Full characterisation of this material is providing new information on crucial CdCl2 treatment of CdTe thin films due to its built-in CdCl2 treatment during the material growth. The work is progressing to fabricate solar cells with this material and compare with CdTe thin films grown by conventional sulphate precursors

Studies on the anti-inflammatory, antipyretic and analgesic properties of Alstonia boonei stem bark.

The methanol extract of the stem bark of Alstonia boonei was investigated for anti-inflammatory property. The analgesic and antipyretic properties of the extract was also evaluated. The extract caused a significant (P<0.05) inhibition of the carrageenan-induced paw oedema, cotton pellet granuloma, and exhibited an anti-arthritic activity in rats. Vascular permeability induced by acetic acid in the peritoneum of mice was also inhibited. The extract also produced marked analgesic activity by reduction of writhings induced by acetic acid, as well as the early and late phases of paw licking in mice. A significant (P<0.05) reduction in hyperpyrexia in mice was also produced by the extract. This study has established anti-inflammatory, analgesic and antipyretic activities of the stem bark of A. boonei