Mar 17, 2023Open Access
In this paper, the properties of golden adornments with four different characteristics were analyzed and compared by means of gold content analysis, XRD analysis, Vickers hardness test and wear resistance test. The results showed that the alignment of Au atomic crystal from 3D electroforming process and 5G process is different from traditional process and former process. Besides, products made by 3D electroforming process have the best Vickers hardness and wear resistance. The mechanical propert...
Aug 30, 2021Open Access
Aluminum alloy is one of the most widely used metal materials in today’s society. Measurement and analysis of its impurity elements can effectively improve the performance of aluminum alloy. Energy dispersive X-ray fluorescence spectrometry (EDXRF) was used to analyze the types and contents of impurity elements in aluminum alloys, and the best working conditions for the EDXRF analyzer to measure impurity elements in aluminum alloys were determined. The absorption and enhancement effect of Al, Zn...
Jul 19, 2021Open Access
The paper deals with the modification effect of dispersed oxides particles (Al2
, MgO, ZrO) on the dendrite structure in low-alloy weld metal. The flux-core wire 1.6 mm diameter for inoculating of oxides powder to weld pool was purposed. Obtained results confirmed an influence of inoculated refractory oxides on dendrites size and morphology, microstructure and mechanical properties of the weld metal.
Jul 09, 2021Open Access
In order to search for secondary gold in the eastern part of Meiganga, alluvial and eluvial field explorations, geological and mineralogical, morphoscopical studies have been carried out in Fell, Gbatoua, and Kombo-Laka. Alluvial and eluvial field explorations have allowed to locate six main concentrations points of gold and heavy minerals (olivine, zo？site, rutile, zircon, …). Many rocks types are found: volcanosedimentary (basalts, rhyolites, conglomerates), metamorphic (quartzites, chlorito...
May 20, 2020Open Access
In this paper, we have discussed the coloration mechanism based on visible absorption spectra testing by selecting three typical samples of Luodian jade with white, pallor and cyan. The attribution analysis of absorption spectra showed that absorption of Luodian jade in visible light mainly includes charge transfer spectrum of Fe2 → Ti4 (at 490 nm - 500 nm) and Fe2 → Fe3 (at 523 nm - 536 nm, 646 nm - 657 nm), electron transition 6A1 → 4T2 (4G) of Fe3 (at 615 nm - 632 nm, 685 nm - 694 nm) an...
Apr 23, 2020Open Access
Toxicity of zinc, cadmium and phenol and their binary mixtures were determined based on inhibition of dehydrogenase activities of yeasts strains isolated from hydrocarbon impacted soil. The yeasts isolated from the hydrocarbon impacted soil were identified as Saprochaete sp. and Cryptococcus sp. The toxicity of chemicals and their mixtures were evaluated in the concentration range of 0 - 16 mM for phenol, 0 - 5 mM for zinc and 0 - 0.4 mM for cadmium. The binary mixture ratios were evaluated. The...
May 29, 2019Open Access
Geometry configurations of joining partners (similar/dissimilar metals) are important to achieve effective and smooth joint in electromagnetic (EM) compression welding. Accordingly, design of welding tool (multi-turn coil) becomes challenging . EM welding of flared D9 flyer tube to SS316 L (N) straight cylindrical plug has been performed under a discharge voltage of 15 - 17 kV with coil current 230 - 250 kA at
May 28, 2018Open Access
This article gives a brief review of scientific researches of high-alloyed chromium-nickel steels stress corrosion cracking (SCC) process of welded joints. Welded joints are one of the most complex objects from the standpoint of the general theory of corrosion fatigue of metals. During their operation a number of problems arise related to the heterogeneity of the material properties, the complexity of the structure, the presence o
Feb 22, 2017Open Access
Forming processes are generally characterized by a high degree of material utilization as well as short process times and, consequently, a decent economic efficiency. Furthermore, incremental forming enables the use of relatively low forming forces which results in a more compact design of the used machines. These conveniences are utilized in terms of roll forming with round tools to form gears and thread
Apr 18, 2016Open Access
This paper focuses on the duplex stainless steel processability and
presents many practical technological approaches which are applied in many steel
companies on how to improve the processability. First, take into consideration an
appropriate hot working temperature; second, make sure cooling rate higher than
15℃/s; and third, conduct annealing treatment before delivery.