An Experimental Investigation into the Explosive Forming of Square Blanks Using Perforated Dies

The explosive forming of steel blanks into a perforated square die of side 200 mm and depth 40 mm has been investigated. The results show that blanks can be successfully formed with perforated dies and that the smaller the percentage of perforation and vent size, the greater the quantity of explosive needed for successful forming. The results also show that the indentation of deformed blanks at the vents is more prominent when large sized vents are used, and decreases with increase in standoff distance. The results also show that better die filling at the corners of the die is obtained if more vents are provided at the corners of the die

Assessment of Physicochemical Properties of some Bitumens from Nigerian Resources

Bitumen is a cheap, common, and important material in today’s technological world. Bitumens gotten at different locations on earth, and produced from different manufacturing processes, or crude feedstocks can however have wide variations in physico-chemical properties and levels of service performances. Hence reliability, handling, and modification in technological usage of different bitumens demands that proper information on a given harvested one should be consulted. Nigeria has large reserves of natural bitumen resources and potentials for sustained production of bitumen in large quantity, but basic applicable public information is lacking on bitumens at most locations of the resources. In this paper, proper test-obtained result of the properties is presented for three bitumen samples obtained from some important sources in the country. Assessment of the results vis-a-vis available information on bitumens elsewhere indicate that any clear surface or underground natural bitumen obtainable in the region of Agbabu village in Ondo State, and a manufactured type from Kaduna Refining and Petrochemical Company (KRPC) in the country are comparable with bitumens of good or acceptable qualities from other locations in the world. Bitumen from the region and the as-manufactured are therefore recommended to be producing in large available quantity and exploiting for different technological applications

Assessment of mechanical properties of mild steel drawn using vegetable fatty-based oils as lubricants

A comparative assessment of the Mechanical Properties (Yield Stress, Yield Strain, Ultimate Stress, Breaking Stress, Breaking Strain, Percentage Elongation and Percentage Reduction in Area) of Mild Steel wires drawn using standard (Sodium Stearate Solution) and three Vegetable fatty oils (Palm Oil, Cotton Seed Oil and Shear Butter) was carried out. The results show that the Vegetable fatty oils produced wires with higher strain-hardening than those of the standard lubricant but with the same ductility and malleability. It also shows that Palm Oil is the best lubricant among the three Vegetable fatty oils considered. Significance Mild steel is the most common metal used in any production process and lubrication is a very important aspect of anyforming process. Fatty based oils are usually used as lubricants in this process. The work looks at the effects of vegetable fatty oils, as lubricants, on the mechanical properties of mild steel