Vol 2, No 1 (Published)





Table of Contents

Original Research Articles

by Nushaba Nubarak Gadzhieva
412 Views, 230 PDF Downloads

Reflection IR spectroscopy, atomic force microscopy (AGM), and electrophysical measurements were used to investigate the formation of surface oxide nanostructures during the radiation oxidation of metallic aluminum in contact with water. It is revealed that the radiation modification of the surface relief is accompanied by the formation of oxide nanolayers, the defectiveness of which is determined by the irradiation time. It is shown that the formation of oxide nanolayers in the region of absorbed dose (0.5-120 kGy) occurs in three stages, which is accompanied by a decrease in electrical conductivity by 5 orders and an increase in the thickness of the oxide layer by an order of magnitude. The role of surface intermediate-active particles in the formation of oxide nanostructures is considered.


Original Research Articles

by А.F. Salenko, V.Т. Shchetinin, G.V. Gabuzian, V.А. Nikitin, S.А. Klymenko, А.М. Potapov, Lj. Tanovic
614 Views, 261 PDF Downloads

Background: Modern composite materials have a number of advantages in comparison with the traditionally used ones and allow implementing new methods of processing, which makes the finished product cheaper and makes its use more efficient.

Objective: In order to improving the surface quality and productivity taken by A functional approach. 

Method: A functional approach to the development of cutting technologies for Carbide and Super Hard Multilayered Composites is considered. It allows, by alternating the effects of different nature, to obtain qualitative edges, to lower the residual stresses in the surface layers, and to achieve a high surface quality. The essence of the approach is that the method of impact is determined on the basis of a morphological search of options for the execution of individual surface elements, each of which, combined into a set, uniquely forms the function of the finished product. The cutting is determined by a rational sequence of execution of technological transitions, provided that each harmful intermediate function at the finish stage turns into neutral or complements the required useful function.

Results: Examples of figured cutting of plates from polycrystalline diamond-containing materials are given, the results of obtaining qualitative edges are shown.

Conclusion: Thanks to the proposed technology based on the use of a functionally oriented approach, the functions of the tool for cutting are divided between the tool itself and the product part. As a result, the processing speed increases more than 3 times, and a high cut quality is achieved.


Original Research Articles

by Hasan Akhyar, Ahmad Farhan2
788 Views, 459 PDF Downloads

This experiment investigated the cooling curve behavior, hardness and microstructure of two aluminum alloys produced by casting process. There are Al-1.37Zn-1.19Si and Al-1.66Si-1.35Zn derived from melting and alloying a pure aluminum with ADC12 (Al-Si) ingot. Cooling curve recorded from both those two alloys with pouring temperature at 710 oC and the mold temperature kept constant at 220 oC. The result shows, a freezing range of Al-1.37Zn-1.19Si alloy is 643–348 oC and Al-1.66Si-1.35Zn alloy is 621–401 oC. Then cooling rate obtained for Al-1.37Zn-1.19Si is 55.56 oC/S, and Al-1.66Si-1.35Zn is 30.09 oC/S. TThe higher hardness is 40.42 BHN at Al 1.66 Si-1.35Zn, while the lower value is 34.62 BHN on Al-1,37Zn-1,19Si alloy. The hardness value found higher when cooling rate is shorted. The number of silicon present on microstructure is highest in Al-1.37Zn-1.19Si alloy but the hardness value decreases. This is caused by the distribution of the silicon content in the alloy is irregular. It was found that the solidification rate had an effect on hardness, where the freezing rate obtained a high hardness value.


Original Research Articles

by Biotza Zubia, Julen Agirre, Eneko SaenzdeArgandona, Lander Galdos, Joseba Mendiguren
568 Views, 333 PDF Downloads

Material formability has become one of the main problems, together with the springback, when stamping high added-value components for the automotive industry. The pursuit of weight reduction has led to higher strength alloys which show a lower formability. Among the different formability criteria (e.g. necking, edge strain, fracture and radius cracks) the edge strain is starting to be a critical aspect on the process planning stage. In order to characterise this criteria, the hole expansion ratio (HER) is conducted under the ISO 16630 standard. In the last years, multiple authors have analysed the HER of different alloys and its dependency on different process variables i.e. cutting method, test speed, material strength. However, the influence of the springback phenomenon on the test result has not been previously analysed. In this work, the influence of the springback on the HER values has been analysed for a mild steel DX54D and a third generation steel Fortiform1050 with a novel measuring technique. From the obtained results, it can be stated that the springback has a critical influence on the characterised HER value, mainly for the third generation steel, leading to differences of about 40% on the HER limits.


Original Research Articles

by Lawrence OLU EKEBAFE1, David E. Ogbeifun1, Felix E. Okieimen1, Osazoduwa M. Ekebafe2
400 Views, 234 PDF Downloads

Abstract

The effects of the application of the graft copolymers (Hydrolyzed starch-g-polyacrylonitrile (HSPAN) and Hydrolyzed starch-g-polyacrylic acid (HSPAA)) on the nitrogen (N) and phosphorus (P) retention capacity of soil was evaluated in this study. Soil nutrient (N and P) retention capacity tests was carried out at three graft copolymers application rates (3.0, 6.0, and 9.0g/kg soil) against a blank soil sample to which graft copolymers was not applied. Diammonium phosphate (DAP) at 0, 100, and 200mg in aqueous solution/kg soil were applied in triplicates. The soil samples were mixed thoroughly and allowed to air-dry. The residual N and P contents of the soil samples were determined and reported as the amounts of nutrients retained as a function of the graft copolymer and DAP application rates. The result of this study has clearly demonstrated the potential of the graft copolymers to alleviate problems related to nutrient loss from the soil media. Leaching of nutrients (N and P) in soil has been found to be reduced to minimal (0.46%N, and 1.13%P) with the application of hydrolyzed graft copolymer and the nutrients are thus available to plant for growth by suction pressure difference.