Experimental Investigation of Lard and Tallow Oils Suitability in Turning Operation of Hypo-Eutectoid Steels

This research is aimed at evaluating the performance suitability of lard and tallow based cutting fluids as potential cutting fluids in turning of hypo-eutectoid steels using carbide cutting tool steels. This was achieved via investigation of the effect of those selected fluids on certain parameters like tool temperature, tool life, spindle power consumption, Work-piece under roughness and chip formations etc., as compared to the conventional mineral oil-based MCFs.Cooling and lubrication in machining are important in reducing the severity of the contact processes at the cutting tool-workpiece interface. Currently, there are wide scale evaluations of the use of metal working fluids (MWFs) in machining, so as to reduce the amount of lubricants in metal removing operations. The increasing awareness of the general public on the environment and health impact of mineral oil-based metal cutting fluids (MCFs) is forcing machine workshop operators to reduce their use as cutting fluids and in search for more environmental friendly animal oil-based cutting fluids. Based on this, commercially available animal oils are currently been exploited as potential oils for formulation of animal oil-based cutting fluids. It is therefore necessary to conduct machining trials to determine the suitability of these oils in metal cutting operations such as turning, drilling and milling etc. This study investigates the effect of the selected cutting fluids on certain machining parameters in turning operations of hypo-eutectoid steels using carbide cutting tool. The selected oils purchased from a local market in Ibadan, Nigeria were sieved to remove any foreign particles or dirt. The solution (water, additives, and base-oil) were mixed at an elevated temperature of 55oC in a proportion 5:1:2.The essence of the emulsifier (additive) was to prevent separation of water from oil. The steel samples obtained from a steel company in Nigeria after spectrochemical analysis, were machined on a variable speed center lathe under different machining parameters. Experimental results clearly showed that Conventional cutting fluid might be replaced with Non-conventional one like LOCFs and TOCFs as they give better performances. With slight modifications and deliberate but careful alterations in some of the components of such oils, better performing cutting fluids could be obtainedSelf-Sponsore

Effects of Precipitation Hardening on Mechanical Properties of Multistage Stirred Cast AA6063 Composites

This research work is to study the effects of precipitation hardening on multistage stirred cast alumina reinforced AA6063 composites which were achieved through production of alumina (Al2O3) reinforced AA6063 alloy, using four stage stir casting method; determination of the effect of precipitation hardening heat treatment on the samples produced; and characterization of the microstructures and some mechanical properties of the cast and precipitation hardened aluminium matrix composite.This work studied the effects of precipitation hardening on multistage stirred cast alumina reinforced AA 6063 composite through production of alumina reinforced AA6063 alloy by four stage stir casting method, determination of effect of precipitation hardening heat treatment and characterization of microstructures and some mechanical properties of as-cast and heat treated samples of aluminium matrix composites. The amounts of AA 6063 and alumina particles required for the production of aluminium composites with 0, 3, 6, 9, 12 and 15 volume percent of alumina were determined by charge calculations. The particles of alumina were initially pre- heated at 300 oC to enhance wetability with aluminium alloy. The AA 6063 alloy was charged into a gas fired crucible furnace and the liquid was allowed to cool to a viscous mass at temperature of about 600 oC so as to introduce alumina particles. Stirring operations were performed manually and mechanically at 750 oC and 300 rpm, to ensure uniform distribution of reinforcement within the matrix, before pouring into permanent metal mould. The samples produced were solutionized at 550 oC for one hour, quenched in water and later aged at 180 oC for 2, 3 and 4 hours. Some samples were reserved for control experimentation. Mechanical responses of the composite were investigated by tensile, hardness and impact test carried out on the samples. The structures of the samples were examined by optical and scanning electron microscopes. The results trend showed that as the volume fraction of alumina and aging time increase, the strength and hardness values also increase with corresponding decrease in impact value. Composite with 15% alumina aged at 4 hours showed highest strength and hardness values of 262.77 MPa and 64.12 BHN, respectively with impact value of 9.86 J. The study showed that multistage stir casting method and precipitation hardening heat treatment are capable of improving the mechanical properties of AA 6063-Al2O3 composites.Self-sponsore

Development of an Ambient Control Method for Tomatoes Preservation

The quality of tomatoes depends on post harvest handling, transportation and storage techniques. Tomatoes cannot be kept for a long period of time due to their perishable and seasonal nature, it is therefore necessary to preserve it in seasons when available in other to ensure constant supply throughout the year with their nutritional value still retained. However, a 0.22 cubic metre capacity storage facility that operates on the principle of evaporative cooling, which is to increase the shelf life of stored tomatoes was designed, fabricated and tested. Data were observed twice daily and Results of the transient performance tests revealed that 117W is the cooling capacity of the produce (tomatoes) at 29.50C. Also, it was observed that the dry bulb (21-300C) and wet bulb (14.5-240C) temperatures are inversely proportional to the relative humidity (39-56%) of the cooler, which in turn show inverse relationship between the saturation efficiency (0-74.42%) and by-pass factor (0.26-1.00). An evaporative cooling system should be utilized to preserve tomatoes and other forms of vegetables at their minimal storage temperature in fourteen days relative to ambient storage. Thus, it has the prospect of being used for short term preservation of tomatoes soon after harvest and it will be very useful in helping the farmers most especially in a developing economy like Nigeria. Key words: Evaporative cooling systems, tomatoes, preservation, temperature, relative humidity, cooling efficiency, cooling capacity.

Development of an Indigenously Made Diesel Fired Crucible Furnace

Most castings in Nigeria are imported, the poor performance of the manufacturing sector in Nigeria is indicative of the low state of the foundry industry of which majority are small–medium scale enterprises with an unsubstantial total productive cost and input to the upper limit of only between 5-20 million naira. This is quite very low compared to that in the US; put the market value of the annual casting shipments at 28-30 billion US dollars produced by approximately 3,200 foundries has been reported. These myriad of problems therefore, necessitated this research workThe technological advancement of any nation have been influenced and uplifted by the extent to which it can usefully harness and convert its mineral resources. The productions of metal in foundries and in all human lives have become a general practice. This work deals with the design, fabrication and performance evaluation of a diesel-fired crucible furnace suitable for use both in the rural and urban areas for casting of different types of metals using indigenously sourced materials and technology. The components of furnace were furnace casing, crucible, furnace cover, burner housing, furnace cover stand, base stand and burner. Mild steel sheet was used for the fabrication of the furnace, while the other components needed for the design were selected based on functionality, durability, cost and local availability. Experimental tests were performed to evaluate the performance of the furnace. The average heating rate of 19.54°C/min was recorded by the furnace and attained a temperature as high as 1420 °C. The furnace also had a melting rate of 454.55g/min for Aluminium. The thermal efficiency of the furnace was determined to be 10.80%. The low value was as result of the large energy wastage due to the type of insulator used in making the furnace wall. The furnace is environmental friendly without health hazards to the workers and can be moved from one place to another unlike the local one.Self-sponsore

Development of an Ambient Control Method for Tomatoes Preservation

Thus, this work is aim at developing an ambient control method for tomato (Lycopersicum esculentum) preservationThe quality of tomatoes depends on post harvest handling, transportation and storage techniques. Tomatoes cannot be kept for a long period of time due to their perishable and seasonal nature, it is therefore necessary to preserve it in seasons when available in other to ensure constant supply throughout the year with their nutritional value still retained. However, a 0.22 cubic metre capacity storage facility that operates on the principle of evaporative cooling, which is to increase the shelf life of stored tomatoes was designed, fabricated and tested. Data were observed twice daily and Results of the transient performance tests revealed that 117W is the cooling capacity of the produce (tomatoes) at 29.50C. Also, it was observed that the dry bulb (21-300C) and wet bulb (14.5-240C) temperatures are inversely proportional to the relative humidity (39-56%) of the cooler, which in turn show inverse relationship between the saturation efficiency (0-74.42%) and by-pass factor (0.26-1.00). An evaporative cooling system should be utilized to preserve tomatoes and other forms of vegetables at their minimal storage temperature in fourteen days relative to ambient storage. Thus, it has the prospect of being used for short term preservation of tomatoes soon after harvest and it will be very useful in helping the farmers most especially in a developing economy like Nigeria.Self-sponsore

Comparative Analysis of Gases Obtained From A Bio-Digester Using Different Waste Media

This work is aimed at comparing and analyzing the composition of gases obtained from a biogas plant using different media. This is achieved through construction of an improvised plant for gas collection, measuring and analyzing the quality of gases obtained in the plant and deducing the best waste medium based on the result obtained.The development of a technological devices and equipment for biogas production from different energy plants and organic wastes has made biogas a renewable source of energy generation. The interest in the use of the biogas as a renewable source of energy is increasing and also the scope of substrates for the anaerobic digestion process is on the increase. With the mini digester it is possible to observe the amount of biogas (methane gas) production and thus the most suitable plant, giving the maximum methane yield, can be determined. The mini digester made of galvanized steel was built, some measurements with energy plants were performed and then parameters such as biogas composition from animal wastes and crop residues were measured (in the laboratory) and compared. The highest biogas and methane yield was recorded in the animal waste. Probable recommendations were later made.Self-sponsore

EFFECTS OF THERMOMECHANICAL TREATMENTS ON THE CHEMICAL AND MECHANICAL PROPERTIES OF Al-Cu Alloy

In this work, the quest is to study the influence of thermo mechanical ageing on Aluminium alloy in which Aluminium is the principal element (parent metal) with traces of other elements such as Copper, Magnesium, Iron, and Zinc. Aluminium is subject to internal stresses and strains when it is overheated.The development of Al-9.37Cu alloy was characterized through metallographic examinations. The alloy having been cast using Die –Casting method was subjected to series of treatment such as solution treatment, water quenching and air-quenching as well as over –ageing. The result showed that the strength of Al9.37Cu was greatly enhanced when the alloy was rolled, and aged. This was as a result of the growth of large precipitates along and near the Aluminum grain boundaries which interfere with the movement of dislocations when the metal yields. However, when the alloy was heated beyond 200oC (500oC), the tensile values were observed to decline as a result of equilibrium tetragonal phase which is fully in –coherent and was characterized with low strengthening effect due to fibrous structures.Self-sponsore