Time-Dependent Ginzburg–Landau equation modelling of electron beam additive manufactured Titanium alloy

In this study, the micro-structure evolution in Electron beam additive manufacturing (EBAM) process of Ti–6Al–4V is studied using phase-field modelling. EBAM involves a rapid solidification process and the properties of a build partly depend on the solidification behaviour as well as the micro-structure of the build material. Phasefield modelling was applied to study the evolution of micro-structural scale of dendrites during the Ti-6Al-4V alloy solidification in the EBAM process. The mechanical properties of the final build parts are dependent on the solidification rate which affects the micro-structure of the material. Thus, the evolving of micro-structure plays a critical and effective role towards process parameters optimization. Recent increase in computational power allows for direct simulations of micro-structures during materials processing for specific manufacturing conditions. A MATLAB code was developed to solve the set of Time-Dependent Ginzburg–Landau equation phase field equations. The effect of under-cooling was investigated through the simulations; the greater the under-cooling, the faster the dendrite grows. The micro-structure simulations shows the growth of primary β phase, which has a body-centred cubic crystal structure phase with four fold symmetry comparable with experimental results for the tested range

Effect of Chemical Treatment on Water Absorption Capability of Polyester Composite Reinforced with Particulate Agro-Fibres

This study determined effects of chemical treatment on the degradation of polyester composite reinforced with agro-fibres. The fibres, after being chemically treated with 1M of hydrogen peroxide, sodium hydroxide and potassium hydroxide solution, were sun-dried and pulverized. Screened particulate fibres obtained from 800 µm sieve were mixed with polyester resin in predetermined proportions. Water absorption test was carried out on the samples and it was observed that the treated fibres showed lower water absorption rates (degradation) as compared with the untreated fibres. The overall responses confirmed the chemical treatment adopted as suitable for pre-treatment of agro-fibres to forestall degradation. Keywords: Agro-Fibres, Chemical Treatment, Degradation, Water Absorption, Particulate, Polyester Composite

Inventing a New Africa through Discovery and Innovations in Computational Material Science

Researchers are increasingly relying on computational technologies to help in simulation of properties of new materials and some areas in materials science has enjoyed some level of success which ranges from composites, to polymer science and to advanced ceramics. This review paper discuss certain developments in the area of computational Materials and how Africa can leverage on this technology to develop their emerging Industries, while dwelling more on application of computational material science in energy sector, since energy has been most pressing challenges in Africa which could be addressed by advanced materials. Also, we summarize part of our research work on galvanic corrosion of mild steel bolt in a magnesium alloy (AZ91D) plate simulation using comsol Multiphysics and 2k factorial experiments on factors that influence the recovery of gold during the upgrade of Ilesha-Itagunmodi, Nigeria gold ore through Froth flotation using Anova software. Attempt have been made to identify existing computational method, challenges of computational materials science deployment in Africa, and how material development can be accelerated through the power of computational material science. With this work, we were able to establish that the strength of computational materials science is in making a connection between the experiment and theories of complex phenomena

Inventing a New Africa through Discovery and Innovations in Computational Material Science

Researchers are increasingly relying on computational technologies to help in simulation of properties of new materials and some areas in materials science has enjoyed some level of success which ranges from composites, to polymer science and to advanced ceramics. This review paper discuss certain developments in the area of computational Materials and how Africa can leverage on this technology to develop their emerging Industries, while dwelling more on application of computational material science in energy sector, since energy has been most pressing challenges in Africa which could be addressed by advanced materials. Also, we summarize part of our research work on galvanic corrosion of mild steel bolt in a magnesium alloy (AZ91D) plate simulation using comsol Multiphysics and 2k factorial experiments on factors that influence the recovery of gold during the upgrade of Ilesha-Itagunmodi, Nigeria gold ore through Froth flotation using Anova software. Attempt have been made to identify existing computational method, challenges of computational materials science deployment in Africa, and how material development can be accelerated through the power of computational material science. With this work, we were able to establish that the strength of computational materials science is in making a connection between the experiment and theories of complex phenomena

2k Factorial Experiments on Factors that Influence the Recovery of Gold during the Upgrade of Ilesha-Itagunmodi Gold Ore through Froth Flotation

A low-grade gold ore from Ilesha-Itagunmodi, south western Nigeria was panned, dried and ball-milled before sieving into fractions. The morphological, mineralogical and chemical composition was studied by optical micro-scopy (Reflected and Transmission), X-ray diffraction (XRD) and Energy Dispersive X-ray fluorescence (XRF), respectively. The sieved fractions were subjected to chemical analysis (AAS). The +106 μm sieve had the highest concentration of the mineral and was then selected for the upgrade through froth flotation using standard rea-gents. In this paper a report on a 2k factorial experiment that provides an understanding of the impact of opera-tional variables on the quantity of gold mineral obtained from the ore during froth flotation is presented. Analy-sis results showed that Ilesha-Itagunmodi gold ore is non-refractory with fine grain particles, amenable to froth flotation and contained about 20 other associated minerals, gold had a concentration of about 0.0024%. A com-bination of P-Xanthate and amine glycol collectors at a pH of 9.2 only produced a considerable increase in gold yield. This translated to about 87.13% increase in recovery of gold from the ore. Analysis of variance (ANOVA) was carried out and the model equation obtained was subsequently optimised to obtain a model equation that could be used in predicting the recoverable quantity of gold, indicating that F11,1-values for Collector concentra-tion, Frother concentration, pH and Conditioning time were 156.86, 6.96, 43.81, and 56.77 respectively. A model with an F value of 88.41 was obtained which indicated that the model was significant. The model equation obtained was subsequently optimised to be able to predict the recoverable quantity of gold. A “Pred R-Squared” value of 0.9365 (93.65%) was also obtained and is in reasonable agreement with the “Adj R-Squared” value of 0.9534 (95.34%). It was established that Ilesha placer gold ore is amenable to froth flotation using standard reagents