Browsing by Author "Ahmed, Ismaila Idowu"
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Item Analysis of intergranular carbide precipitate in haz of martensitic stainless steel(Taylor’s University, Malaysia, 2017) Ahmed, Ismaila Idowu; Adebisi, Jeleel Adekunle; Yahaya, Taiwo; Abdulkareem, Sulaiman; Sherry, Andrew H.Analysis of intragranular carbide precipitate in the Heat Affected Zone (HAZ) of Martensitic Stainless Steel (MSS) weldment was carried out. Low carbon grade martensitic stainless steel weldment subjected to four point bend test in simulated sweet crude environment was analysed with Transmission Electron Microscope (TEM). The optical microscopy of the failed sample revealed the presence of intergranular cracks on both sides of the weldment in the HAZ. Electron transparent sample for TEM was prepared from the HAZ of the weldment using extraction replica technique. The examination of TEM specimen in imaging mode revealed the presence of precipitates on grain boundaries. The compositional analysis of the precipitates was carried out with Energy Dispersive X-ray (EDX). The result of EDX analysis showed the presence of chromium and molybdenum, this suggests, the precipitates were carbides of the form M23C6. The study therefore upholds sensitisation as the mechanism behind the intergranular cracks observed in the HAZ of the MSS weldment.Item Assessment of Crack Propagation Mode in Martensitic Stainless Steel HAZ with Electron Back Scatter Diffraction: Effects of Environmental Variables(Universitatea Politehnica Timisoara (UPT), Romania, 2016-05) Ahmed, Ismaila Idowu; Adebisi, Jeleel Adekunle; Yahaya, Taiwo; Aremu, Ishaq Na'Allah; Sherry, Andrew H.In this study, an assessment of crack propagation mode in martensitic stainless steels heat affected zone was carried out with electron back scatter diffraction (EBSD) with focus on the effect of environmental variables. Girth welded samples were subjected to four point bend tests in sour and sweet environments. Scanning electron microscope and electron back scatter diffraction technique were both used to study the crack propagation mode and interaction of crack tip with microstructures. Study showed that sample tested in sour environment failed with transgranular cracking and samples tested in sweet environment failed with intergranular stress corrosion cracking mode. The proposed mechanism for the failure was sulphide stress corrosion cracking and intergranular precipitation of carbide by sensitisation process respectively. The correlation between crack path and grains misorientation was studied with aid of EBSD technique.Item Assessment of Deformation Twinning in Cold Rolled Austenitic Stainless Steels with Electron Back Scatter Diffraction(Faculty of Engineering and Technology, University of Ilorin, 2014-06-09) Ahmed, Ismaila Idowu; Wright, David; Adebisi, Jeleel Adekunle; Aremu, Ishaq Na'Allah; Yahaya, Taiwo; Quita da Fonseca, JoaoDeformation twinning has traditionally been studied with Transmission Electron Microscopy (TEM). In this study, an assessment of deformation twinning in Austenitic Stainless Steel (ASS), type 304L, cold rolled to 20% reduction was investigated using Scanning Electron Microscopy (SEM) and Electron Back Scatter Diffraction (EBSD) techniques rather than the conventional TEM. The study revealed the presence of deformation twins in the cold rolled grains of ASS. It emerged from the study that the deformation twins observed may facilitate localised heterogeneous deformation and development of internal stresses within the grain.Item Assessment of Metallic Contaminants in Grinded Millet using Domestic Grinding Machine(Faculty of Engineering and Technology, University of Ilorin, 2016) Odusote, Jamiu Kolawole; Soliu, Ganiyat A.; Ahmed, Ismaila Idowu; Abdulkareem, Sulaiman; Akande, Kareem AkandeIn this study, the quantity of metallic contaminants extracted from grinded millet was evaluated. The millet was grinded in three different forms; wet, paste, and dry forms for up to 3 minutes using locally fabricated grinding machine with cast grinding discs. Separate grinding discs were used for different millet forms, while the same quantity of millet, 1 kg, was used throughout the experiments. The millet was soaked for 24 hours before grinding in order to obtain wet and paste forms of the millet. Metallic contaminants were carefully extracted from the grinded millet using magnetic bed along with sedimentation and decantation. The extracted materials were then quantified to ascertain the food form that produces the highest amount of metallic contaminants. Also, the wear rate of the grinding disc was also determined with respect to the grinding time. The results show that the wet form has the highest amount of metallic contaminants of about 1.397 g followed by the paste form with 1.075 g. The dry form has the least value corresponding to 0.945 g. The grain sizes of the metallic contaminants were calculated to be 12.095 nm for the wet form, 8.056 nm for paste form while the dry form has the smallest grain size of 3.124 nm. The results revealed that metallic contaminants are always contained in grinded food processed with local grinding discs. Thus, materials with better wear resistance should be selected for production of grinding discs to be used for food processing.Item Carbo-Nitriding of AISI 1018 Steel Plate with Animal Horn(Mechanical Engineering, University of Ibadan, 2016) Ahmed, Ismaila Idowu; Mohammed, Aminat T.; Adebisi, Jeleel Adekunle; Yahaya, Taiwo; Ambali, I. O.The research on the carbonitriding of AISI 1018 steel with animal horn was carried out with the aim of converting waste to wealth through re-use approach of waste management. Cattle horn was processed into two different morphologies namely: powder and flakes. Carbonitriding heat treatment was carried at 850oC and 450oC for carburizing and nitriding dominated processes respectively. Vickers hardness measurement was carried out on samples heat treated with horn powder and flakes. Optical metallography was carried out on carbonitrided sample for microstructural examination following the heat treatment. The results of the investigation showed that hardness gradient occurred with higher hardness value at the near surface and decreasing towards the core. Sample heat treated with horn flakes showed higher hardness than those that was heat treated with horn flakes. Microstructural examinations of carbonitrided samples revealed the presence of martensite and retained austenite. From the result of study, it was concluded that the high hardness values observed was attributed to the diffusion of carbon and nitrogen atoms to the interstices of the host atom. Again the solute atoms helps to stabilise austenite microstructures which later transformed to martensite observed in the optical micrographs.Item Combustion Characteristics of Bio-Degradable Biomass Briquettes(Taylor’s University, Malaysia, 2018-09) Abdulkareem, Sulaiman; Akeem, B. A.; Ahmed, Ismaila Idowu; Ajiboye, Tajudeen K.; Adebisi, Jeleel Adekunle; Yahaya, TaiwoThis paper reports on the combustion characteristics of biodegradable biomass briquettes prepared from charcoal, sawdust and sugarcane bagasse. The three materials were mixed in respective ratio of 20:20:60, 20:30:50, 20:40:40, 20:50:30 and 20:60:20. The briquettes were produced using Budenberg dial gauge hydraulic compression machine with the formation of briquettes under 64 MPa pressure with 120 seconds dwell time. Combustion characteristics such as proximate analysis, fuel-burning rate, fuel ignition time and afterglow time of the produced briquettes were determined. Results show that briquette with sample composition of 20:50:30 has better calorific value of 24613.69 kJ/kg and sample with ratio 20:30:50 has lowest calorific value of 22500.3 kJ/kg, while sampling with ratio 20:30:50 has better physical properties with shatter resistance of 99.61% and porosity index value of 47.40%.Item Deformation path effects on the internal stress development in cold worked austenitic steel deformed in tension(Elsevier, 2014-07-05) Ahmed, Ismaila Idowu; Grant, Benedict; Sherry, Andrew H.; Quinta da Fonseca, JoaoThe effects of cold work level and strain paths on the flow stress of austenitic stainless steels, including Bauschinger effect and associated internal stresses were investigated with both mechanical testing and neutron diffraction techniques. The main objective was to assess the effects of cold rolling: to 5%, 10%, 20% and 40% reduction and uniaxial straining on the evolution of the internal strains during the re-straining to 5% tensile strain in-situ, which is relevant for stress corrosion cracking (SCC) studies. The results of mechanical testing showed that the yield strength of material increased when it was reloaded in the forward direction and decreased well below the flow stress when the loading direction was reversed, showing a strong Bauschinger effect. The magnitude of Bauschinger effect is independent on whether tensile or compressive prestraining comes first but rather on the amount of prestrain. The assessment of the effect of prestraining methods showed that the magnitude of yield asymmetry was higher in the material prestrained by uniaxial deformation than those prestrained by cold rolling. Neutron diffraction test results showed that the elastic lattice strain difference between the maximum and minimum strain values increased consistently with the applied stress during the re-straining to 5% tensile strain in-situ along the 3 orthogonal directions of the rolled plate. It also emerged that, following the in-situ loading of cold rolled materials to 5% tensile strain, the largest strain difference occurred in the material prestrained to 20% reduction. In cold rolled samples, the peak width increased with cold work levels and during re-straining to 5% along rolling, transverse to rolling and normal directions which simulated reversed condition. In contrast to the cold rolled samples, there was neither increase nor decrease in the peak width of samples prestrained by uniaxial deformation on re-straining in reverse direction. This was rationalised in terms of the development of intragranular and intergranular stresses in the two cases and implications to SCC susceptibility were discussed.Item Design and Fabrication of Electric Muffle Furnace(Civil Engineering Department, University of Ilorin, 2018) Ahmed, Ismaila Idowu; Adebisi, Jeleel Adekunle; Busari, Yusuf O.; Ogunbiyi, I. B.; Gbadebo, A. O.; Adeko, A.; Omowumi, A.; Olanrewaju, S. O.; Abdulkareem, SulaimanThis work was aimed at the design and fabrication of heat treatment furnace, with automatic control system, using locally sourced materials. Computer- Aided Design (CAD) and Autodesk Inventor Professional were used for the structural design. And, consistent with materials selection procedures, mild steel was selected for the fabrication of casing, while other appropriate materials for the construction were selected based on service need using their relevant properties, cost considerations and ease of fabrication into the various component parts. The International Electric Equipment (IEE) regulation (BS 7671) was also followed in electrical and electronic components design to ensure compliance with the international standard. Performance evaluation of the muffle furnace showed a maximum attainable temperature of 920°C inside the enclosed heating chamber after a period of 15 minutes of continuous heating. This showed that, the furnace is suitable for all forms of heat treatment and melting of both ferrous and non-ferrous metals within the maximum attainable temperature. The maximum operating temperature of 650°C was therefore advised to ensure health and safety and extended operation life of the heating element.Item Development and Performance Evaluation of Soy Adhesive(Civil Engineering Department, University of Ilorin, 2018) Ahmed, Ismaila Idowu; Abiodun, Lois OmololaPresently, particleboards are mainly produced with wood particles andurea-formaldehyde (UF) resins. The emission of carcinogenic formaldehyde in theproduction and use of particleboard has generated an urgent need for development of a formaldehyde-free wood adhesive for particleboard production. The aim of this research is to develop and conduct performance evaluation of soy adhesive, a green alternative that is not harmful to human health (carcinogenic free). In this work, soy adhesive was produced from soya beans and applied as binder in the production of particle board from wood dust often considered as wastes. The adhesive was added to the wood dust at different mixing ratios (weight ratio) and sieve sizes. The composite produced were compacted by cold pressingand subsequently dried at room temperature and in the oven at temperature of 105oC. The particle boards produced were tested for the performance evaluation. Physical properties namely, density, water absorption (WA) and thickness swelling (TS), and mechanical properties including Modulus of Elasticity (MOE) and Modulus of Rupture (MOR) wereassessed as a function of mixing ratios according to the ASTM D-1037-99standard. The water absorption and TS were measured after 24 hours of soaking in water. It was observed that density decreased with increase in the proportion of the sawdustin theratio. Similarly, the MOE and MOR of the fabricated particle board decreased with increase in the amount of sawdust in the mix. However, the water absorption and TS increased with proportion of saw dustin the mixing ratioItem Development of a Composite Material for Learning and Teaching Purposes(Materials Science and Technology Society of Nigeria (MSN), 2014) Abdulkareem, Sulaiman; Adebisi, Jeleel Adekunle; Ahmed, Ismaila Idowu; Salami, O. R.This paper reports on the developed magnetic board composite from waste materials for use in education sector as teaching aid. The composite material was prepared using iron fillings from metal machining (cutting) processes and sawdust obtained from wood waste. The determination of the sieve analysis of the two materials was carried out to obtain particle sizes of 0.4um and 1.0um for the iron fillings and sawdust respectively. The two materials were mixed in various percentage to obtain optimum composition from the aggregates formed. An appropriate binder was used for binding the various composition together. The resulting aggregates were cast into the required shapes and sizes, compacted and allowed to dry at ambient temperature for 5 days. Durability test was carried out for tensile stress, compressive stress and the material density. The performance evaluation of the composite was carried out by embedding the composite material into the prepared board used for charts, graphical image and data as well as improvement in time utilization during a 60-minute lecture period.Item Effect of Date Seed Particulates on Mechanical Properties of Aluminium Alloy(Faculty of Engineering Hunedoara, University Politehnica Timisoara, 2018) Abdulkareem, Sulaiman; Edache, E. J.; Olowosule, I. I.; Kolawole, M. Y.; Ahmed, Ismaila Idowu; Ajiboye, Tajudeen KThe results of an experimental investigation of mechanical properties of date seed particles reinforced aluminium alloy composites, processed by stir casting method are reported in this paper. Two sets of composites with date seed of 300 and 500 µm particle sizes were used. The ranges of particle size used were based on the weight fraction when sieve analysis was conducted on the sample collected for the work. Each grain size had four types of composite samples with the reinforcement weight fractions of 5, 10, 15 and 20%. The mechanical properties considered were the tensile strength, Impact and hardness behaviors. Unreinforced aluminium alloy samples were also tested for the same properties. It was found that the hardness and tensile strength increases with the increase in the weight fraction and the fracture toughness decreases with increase in the weight fraction of reinforced date seeds particles. It was concluded that the improvement in the mechanical properties can be well accredited to the high dislocation density.Item Effect of Heat Input on the Mechanical and Corrosion Behaviour of Smaw Mild Steel(University of Novi Sad, Serbia, 2017-11-29) Busari, Yusuf O.; Ahmed, Ismaila Idowu; Shuaib-Babata, Yusuf LanreThis study was carried out to assess the effect of heat input on the mechanical properties and corrosion behaviour of mild steel. The intrinsic nature of fusion welding has made it difficult to provide a complete understanding of corrosion behaviour in some systems. Optical metallography was used to determine grain size and HAZ zone, weldment and parent metal. Mechanical properties of the weldment were observed. Corrosion behaviour of mild steel were investigated in air, sea water, alkaline and acidic medium after welding with shielded metal Arc welding SMAW by varying the welding process parameter that leads to power input and monitoring its welding speed with a stop watch. The microstructural characterization of the welded sample carried out through a metallurgical microscope (x100) and the corrosion response rate by weight loss was observed in the different medium, the sample welded with 180A and low voltage displayed the highest Rockwell hardness and the same was observed for impact test. The effect of various heat inputs on the corrosion behaviour of shielded metal arc welded mild steel show thus the as-received sample have the greatest resistance to corrosion in all the medium, at 180 A, high voltage this is closely followed by sample welded with 180 A, low voltage. The sample welded with 90A, low voltage which has the least corrosion resistance in all medium during the exposure period studied. The low heat input welded samples underwent a long period of heating, low heat input could lead to a greater tendency of distortion which may produce a higher weld cracking in the aggressive corrosion medium. The higher the current, the higher the power input and the deeper the penetration. However, the use of too high weld current may cause problems such as excessive spatter, electrode overheating and cracking while too high weld voltage could cause the beads to be wider and flatter. The low arc voltage produces a stiffer arc that improves penetration. If the voltage is too low, a very narrow bead will result.Item Effect of heat input on the mechanical and corrosion behaviour of SMAW mild steel(Journal of Production Engineering, 2017) Busari, Yusuf Olanrewaju; Ahmed, Ismaila Idowu; Shuaib-Babata, Yusuf LanreThis study was carried out to assess the effect of heat input on the mechanical properties and corrosion behaviour of mild steel. The intrinsic nature of fusion welding has made it difficult to provide a complete understanding of corrosion behaviour in some systems. Optical metallography was used to determine grain size and HAZ zone, weldment and parent metal. Mechanical properties of the weldment were observed. Corrosion behaviour of mild steel were investigated in air, sea water, alkaline and acidic medium after welding with shielded metal Arc welding SMAW by varying the welding process parameter that leads to power input and monitoring its welding speed with a stop watch. The microstructural characterization of the welded sample carried out through a metallurgical microscope (x100) and the corrosion response rate by weight loss was observed in the different medium, the sample welded with 180A and low voltage displayed the highest Rockwell hardness and the same was observed for impact test. The effect of various heat inputs on the corrosion behaviour of shielded metal arc welded mild steel show thus the as-received sample have the greatest resistance to corrosion in all the medium, at 180 A, high voltage this is closely followed by sample welded with 180 A, low voltage. The sample welded with 90A, low voltage which has the least corrosion resistance in all medium during the exposure period studied. The low heat input welded samples underwent a long period of heating, low heat input could lead to a greater tendency of distortion which may produce a higher weld cracking in the aggressive corrosion medium. The higher the current, the higher the power input and the deeper the penetration. However, the use of too high weld current may cause problems such as excessive spatter, electrode overheating and cracking while too high weld voltage could cause the beads to be wider and flatter. The low arc voltage produces a stiffer arc that improves penetration. If the voltage is too low, a very narrow bead will result.Item Effect of strain paths and residual delta ferrite on the failure of cold rolled austenitic stainless steels, type 304L(SAGE, 2013-03-15) Ahmed, Ismaila IdowuThe effects of martensite development on lattice strain evolution during the in situ compression of austenitic stainless steels, Type 304L, at ambient and cryogenic temperatures were investigated. Engin-X neutron diffractometer was used to study the change in the lattice strain during the uniaxial compression to 10% strain in situ. The report found no evidence of martensite during the compression test at ambient temperature. Similarly, no martensite was observed at cryogenic temperatures up to the applied load of 200MPa in the elastic region. Martensite was only observed during the plastic deformation at cryogenic temperatures up to the applied strain of 10%. The presence of martensite in the austenitic stainless steels microstructure reinforces the austenite matrix. This was evident from the decrease in the lattice strain as the deformation temperature decreases.Item Effects of martensite development on lattice strain evolution during the in situ deformation of austenitic stainless steels at cryogenic temperatures(SAGE, 2013-03-15) Ahmed, Ismaila Idowu; Quinta da Fonseca, J; Sherry, Andrew H.The effects of martensite development on lattice strain evolution during the in situ compression of austenitic stainless steels, Type 304L, at ambient and cryogenic temperatures were investigated. Engin-X neutron diffractometer was used to study the change in the lattice strain during the uniaxial compression to 10% strain in situ. The report found no evidence of martensite during the compression test at ambient temperature. Similarly, no martensite was observed at cryogenic temperatures up to the applied load of 200MPa in the elastic region. Martensite was only observed during the plastic deformation at cryogenic temperatures up to the applied strain of 10%. The presence of martensite in the austenitic stainless steels microstructure reinforces the austenite matrix. This was evident from the decrease in the lattice strain as the deformation temperature decreases.Item Effects of Soaking Time and Cold Work on Sensitisation of Austenitic Stainless Steels(University of Novi Sad, Serbia, 2015-10-20) Ahmed, Ismaila Idowu; Adebisi, Jeleel Adekunle; Yahaya, Taiwo; Abdulkareem, SulaimanThe effects of soaking and coldworks on sensitisation of austenitic stainless steels were studied. Annealed and samples coldworked to 20% and 40% were subjected to sensitisation heat treatment at 650 C for 24 and 72 hours. Metallographic analysis carried out showed that sensitisation occurred in both annealed and coldworked samples which manifested as ditches. Soaking for 72 hours showed more ditches than 24 hours. Intergranular ditches were more prevalent in annealed and lower coldworked samples. In contrast, heavily coldworked samples were more susceptible to transgranular carbide precipitation evident by ditches on slip bands and recrystallised grains.Item The Influence of Composition and Plastic Strain on the Electrochemistry of Stainless Steels Doped with Platinum Group Metals(Materials Performance Centre, University of Manchester, 2009-03) Govender, Kuveshni; Necib, O.; Ahmed, Ismaila Idowu; Lyon, Stuart B.; Sherry, Andrew H.Corrosion-related degradation of stainless steel components of Naval Nuclear Power Plant (NNPP) can have significant impact on the cost of nuclear ownership through inspection requirements, the reliability and, in some cases, the availability of plant. This project aims to establish an improved physical understanding of the mechanisms of Stress Corrosion Cracking (SCC) of 304 stainless steel of the type used for a range of NNPP components. In order to accomplish this aim, the research is studying the influence of platinum group metal (PGM) alloying additions (i.e. < 1 wt.%, additions palladium and/or ruthenium) on the SCC of 304 stainless steel as these have predictable effects on the electrochemical processes of corrosion. The approach includes mechanical and electrochemical testing together with pre- and post-test metallurgical examination (over an appropriate range of length scales), and finally predictive model development. This Report presents experimental data relating to the influence of PGM additions and plastic-strain (cold work) on the electrochemistry of 304L stainless steel in a range of environments including simulated PWR water. The electrochemical data reveal ruthenium to be more effective than palladium in enhancing the corrosion resistance of 304 stainless steel in PWR water chemistry and this was traced to removal of palladium from the alloy matrix by precipitation of a PdMn Intermetallic 2nd phase precipitate (reported previously). For all alloy variants, increasing temperature shifted the Open Circuit Potential (OCP) to more noble values and increased the anodic current density; observations consistent with enhanced to both metal dissolution and oxygen diffusion rates at higher temperatures. Increasing the oxygen concentration increased the OCP but decreased the passive current density; observations rationalised in terms of the efficiency of the cathodic reaction in which PGM additions enhance the exchange current density for oxygen reduction leading to faster passivation kinetics. In hydrogenated water, the PGM modified alloys displayed a preferred lower OCP and a higher anodic current density than the standard alloy and this is because PGM additions increase the exchange current density for hydrogen oxidation. In deaerated pressurised water at 260oC, the ruthenium-doped alloy displayed an improved corrosion resistance compared with standard 304 stainless steel whilst the palladium-doped alloy displayed a higher dissolution current density. Studies in acidified aerated potassium tetrathionate revealed an abrupt transition of the OCP to more positive potentials the effect being more rapid for the ruthenium-doped alloy. Analysis of the anodic polarisation curves suggests that PGM additions enhance the corrosion resistance, the effect being most pronounced for ruthenium. Regarding the effect of plastic strain (cold work), the influence of strain path on the evolution of internal strain in cold-worked austenitic stainless steel was investigated using neutron diffraction and mechanical testing. As expected, hardness and yield strength increase with the level of cold work, however the magnitude of the increase is dependent upon the strain path due to the mixed isotropic/kinematic hardening response. Neutron diffraction demonstrated that residual strain in cold-worked material increases with the level of cold work. The elastic anisotropy and the lattice strain difference increased consistently with the applied stress during in-situ re-straining tests. In considering all the cold work material reloaded in-situ to 5 % in tension along the 3 principal directions, the largest strain was found to occur in the material with the pre-strain level of 20 % reduction. Electrochemical data indicate that the sample orientation (and, consequently the alloy texture) has a greater effect than the absolute level of cold work. Thus, the L-T plane displayed more noble electrochemical behaviour than the L-S plane, and the T-S plane was found to be least noble. Generally, material cold rolled to 20% reduction showed the least noble electrochemical behaviour of all the cold rolled materials on all three orthogonal planes.Item Investigation of surface residual stress profile on martensitic stainless steel weldment with X-ray diffraction(Elsevier, 2016-01-19) Ahmed, Ismaila Idowu; Adebisi, Jeleel Adekunle; Abdulkareem, Sulaiman; Sherry, Andrew H.The development of residual stresses during fabrication is inevitable and often neglected with dire consequences during the service life of the fabricated components. In this work, the surface residual stress profile following the martensitic stainless steel (MSS) pipe welding was investigated with X-ray diffraction technique. The results revealed the presence of residual stresses equilibrated across the weldment zones. Tensile residual stress observed in weld metal was balanced by compressive residual stresses in the parent material on the opposing sides of weld metal.Item Investigation of Thermal Insulation Properties of Biomass Composites(Faculty of Engineering Universitas Indonesia, 2016-09) Abdulkareem, Sulaiman; Ogunmodede, S.; Aweda, Jacob O.; Abdulrahim, A. T.; Ajiboye, Tajudeen; Ahmed, Ismaila Idowu; Adebisi, Jeleel AdekunleThis paper reports on the investigation of thermal properties of Kapok, Coconut fibre and Sugarcane bagasse composite materials using molasses as a binder. The composite materials were moulded into 12 cylindrical samples using Kapok, Bagasse, Coconut fibre, Kapok and Bagasse in the ratios of (70:30; 50:50 and 30:70), Kapok and Coconut fibre in the ratios of (70:30; 50:50 and 30:70), as well as a combination of Kapok, Bagasse and Coconut fibre in ratios of (50:10:40; 50:40:10 and 50:30:20). The sample size is a 60mm diameter with 10mm – 22mm thickness compressed at a constant load of 180N using a Budenberg compression machine. Thermal conductivity and diffusivity tests were carried out using thermocouples and the results were read out on a Digital Multimeter MY64 (Model: MBEB094816), while a Digital fluke K/J thermocouple meter PRD-011 (S/NO 6835050) was used to obtain the temperature measurement for diffusivity. It was observed that of all the twelve samples moulded, Bagasse, Kapok plus Bagasse (50:50), Kapok plus Coconut fibre (50:50) and Kapok plus Bagasse plus Coconut fibre (50:40:10) has the lowest thermal conductivity of 0.0074, 0.0106, 0.0132, and 0.0127 W/(m-K) respectively and the highest thermal resistivity. In this regard, Bagasse has the lowest thermal conductivity followed by Kapok plus Bagasse (50:50), Kapok plus Bagasse plus Coconut fibre (50:40:10) and Kapok plus Coconut fibre (50:50).Item Metallographic Characterisation of Cold Worked Type 304 Austenitic Stainless Steels(Materials Performance Centre, University of Manchester, 2007-09) Ahmed, Ismaila Idowu; Scenini, Fabio; Sherry, Andrew H.The influence of cold work on the Stress Corrosion Cracking (SCC) susceptibility of Austenitic Stainless Steels (ASS) is an ongoing topic of research. While some workers have suggested that low levels of cold work are deleterious to SCC, others argue that high levels may be favourable to SCC under certain conditions. The objective of this report is to quantify a number of key parameters associated with the influence of cold work on SCC susceptibility. The microstructures of ASS subjected to different deformation modes and different levels of cold work have been examined using a range of techniques: optical metallography was carried out to determine the grain size and elongation ratio; the X-ray diffraction technique was used to quantify the amount of strain- induced martensite and residual stress; and lastly, deformation texture was examined using Electron Back Scatter Diffraction (EBSD) technique. In addition, Vickers hardness was used to quantify the material hardness in each condition of cold work. The outcome of the characterisation showed that the Vickers hardness and the volume fraction of strain induced martensite increases with both increasing levels of cold work and weight percent of carbon in the material composition. The stability of delta ferrite was also affected by the proportion of ferrite-stabilising elements (e.g. Si) in the composition. Bi-rolling (i.e. cross- rolling) significantly increased the hardness value and the amount of strain induced martensite compared with samples in which cold work was generated either by uniaxial rolling and pulling (i.e. tensile cycling). Cross-rolling also led to a more uniform distribution of delta-ferrite within the microstructure than either unidirectional rolling or pulling.