INTERNATIONAL JOURNAL OF ENGINEERING PROCESSING AND SAFETY RESEARCH
VOL. 29 NO. 5 – SEPT., 2023
CAMBRIDGE RESEARCH AND PUBLICATIONS INTERNATIONAL,
Africa (Nigeria): CAHDC, University of Nigeria, Nsukka, Enugu State, Nigeria.
PRECIPITATION HARDENING OF ALUMINUM ALLOYS – A REVIEW
OLOGUNYE O.B 1, AZEEZ R.O 1, FADARAT G. 1, HADI I. 1
1Department of Mechanical Engineering, Federal Polytechnic, Ede, Osun State, Nigeria.
Structures with a substantial ratio of strength to weight are traditionally made of aluminum, as is the case with the automotive and aerospace industries. One of the most common methods of improving the alloy of metal is hardening by precipitation, often known as age hardening. Precipitate distribution can be found in the microstructures of aluminum alloys from the 2xxx, 6xxx, and 7xxx families, which are often used in the automotive and aerospace industries. Customizing the precipitate distribution is one way to improve engineering effectiveness because the interactions between dislocations and precipitates primarily determine the mechanical characteristics of these alloys. This review’s objective was to give a succinct summary of the state of the art in precipitation kinetics. Starting with the basic scenario of homogeneous precipitation of diluted coherent phases and moving up through various tiers of supplementary complexity related to the diffusion methods, the effect of finite volume fraction, the effect of particle shape, competitive multi-phase precipitation, heterogeneous nucleation, and non-isothermal efficacy. This article also generalized the precipitation and strengthening behavior in aluminum alloys. First, the processes accountable for precipitation strengthening and the morphological development of second-phase particles are discussed. Underlined are the impacts of time and temperature, the significance of plastic deformation, and the difficulties posed by precipitation hardening.
Keywords: Aluminum, Precipitate, Harden, Deformation, Microstructure, Dislocation
IMPACTS OF FIBER LOADING ON THE PHYSICAL AND MECHANICAL CHARACTERISTICS OF TREATED GROUNDNUT SHELL POWDERS REINFORCED WASTE POLYSTYRENE FOAM COMPOSITES
AKABE, MOHAMMED1*; ABDULLAHI, NURADDEEN BAKORI 2; and AMINU, UBA ALHASSAN3
1,2&3 Department of Chemical Engineering, Kaduna Polytechnic, Kaduna, Kaduna State – Nigeria.
The aim of this study was to see how fiber loading influences the physical and mechanical characteristics of waste polystyrene foam (WPSF) matrix composites reinforced with treated groundnut shell powders (TGSP). The treated groundnut shell fiber or powder was treated using 10% NaOH before using it as reinforcement in WPSF. The treated groundnut shell powder and polystyrene foam loadings were varied from 0 to 50 wt% treated groundnut shell powder and 100 to 50 wt% polystyrene foam. The primary findings of this investigation revealed that the physical parameters of the composites (density, water absorption, and hardness) increased linearly as the fiber content increases. The mechanical properties of the composites (tensile strength, modulus of elasticity, flexural and compressive strength) increases with an increase in the fiber content up to 20 wt% TGSP loading before declining as the TGSP content was increased further. The percentage elongation at break of composites produced decreased with increases in fiber content. However, composites made with 20 wt% TGSP demonstrated superior fiber/matrix adhesion, as well as improved physical and mechanical properties, making treated groundnut shell powder reinforced polystyrene foam composites appropriate for industrial applications.
Keywords: Composite, Waste Polystyrene Foam, Groundnut Shell Powders, Fiber Loading, Reinforcement, Physical Properties
COMPARISON BETWEEN TENSILE AND FLEXURAL STRENGTHS OF BAMBOO WITH SOME SELECTED STEEL SIZES IN REINFORCED COLUMNS AND BEAMS IN BUILDING CONSTRUCTION
UMAR L.; OTUNOLA O.O.; KOMOLAFE T.F.; OYENIYAN W.A.; & AJALA A.K
Civil Engineering Department, Federal Polytechnic Offa, Kwara State, Nigeria.
Comparison of bamboo and steel reinforced concrete was carried out using concrete cubes of different ages. The tensile and flexural strengths of bamboo with some selected steel sizes in reinforced columns and beams were calculated. Resistance of the reinforced concrete beams to both transverse and longitudinal stresses was compared. The compressive strength after curing the cubes for 7 and 28 days were found to be 17.73N/mm2 and 25.43N/mm2 respectively and modulus of elasticity was 23701N/mm2. The results show that high yield steel bar has higher resistance to tension giving a tensile strength ranging from 457N/mm² -712N/mm²; Yield stress of 379N/mm²- 552N/mm² and a tensile force ranging from 35kN – 143kN. Bamboo can be said to be very poor in tension giving a tensile strength of 31N/mm²- 69N/mm²; Yield stress of 0N/mm² – 49.45N/mm² and a tensile force value of 3kN – 14kN. The ductility of steel allows it to undergo plastic deformation and necking before breaking. Bamboo undergoes brittle failure. i.e., it breaks sharply without plastic deformation. This property is demonstrated from the result of breaking elongations obtained. High yield is most ductile giving a breaking elongation value of 19% – 35% while, bamboo which undergoes brittle failure gives a breaking elongation of 0% – 15%.
Keywords: Flexural Strength, Bamboo, Yield Steel, Elasticity, Deformation
SAFETY RULES AND REGULATIONS IN SOME INDUSTRIES AND VOCATIONAL AND TECHNICAL INSTITUTIONS IN NIGERIA: PREVENTIVE MEASURES AGAINST ACCIDENTS OCCURRENCE
NICODEMUS STEPHEN GAYA
Department of Technical Education Adamawa State College of Education, Hong – Nigeria.
Providing accomplished safety and suitable work environment is the most important obligation/responsibility of employers when they organize their units and delegate workers with different responsibilities. Workers also anticipate harmless and healthy environment which is their fundamental right. Generally, safety is of utmost importance and it is the responsibility of everyone. Unsafe work conditions have negative impact on employees’ performance and may lead to reduction in productivity and growth of the organization. Globally, industrial or workplace related accidents and mortalities are on rapid increase. In this regard, some countries have formulated regulations and recommended legislations which authorized hazardous industries to comply with all safety rules and regulations, possess protective gears and equipment, have prompt rescue and rehabilitation systems and safety and health section with competent workers to oversee the above parameters. This paper tends to critically examined the meaning of accidents, classification of accidents, some common types of workplace injuries incurred as a result of accidents, some common causes of workshop accidents, consequences of accidents, meaning of safety and some safety rules and regulations which are preventive measures against accident occurrence.
Keywords: Safety, Rules, Regulations, Preventive, Accidents