scholarly journals Modification of Aluminium-Silicon Near-Eutectic Alloy with Use of Electrolysis of Sodium Salt

2017 ◽  
Vol 62 (4) ◽  
pp. 2371-2374 ◽  
Author(s):  
A. Białobrzeski ◽  
J. Pezda ◽  
A. Jarco

AbstractThe present work discusses results of preliminary tests concerning the technology of continuous dosage of sodium to a metallic bath from the aspect of modification of EN AC-44200 alloy, through the use of a multiple compound (salt) of sodium. The technology consists in continuous electrolysis of sodium salts occurring directly in a crucible with liquid alloy. As a measure of the degree of alloy modification over the course of testing, the ultimate tensile strength (UTS or Rm) and analysis of microstructure are taken, which confirm the obtained effects of the modification on the investigated alloy. Assurance of stable parameters during the process of continuous modification with sodium, taking into consideration the fact of complex physical-chemical phenomena, requires additional tests aimed at their optimization and determination of a possibility of implementation of such technology in metallurgical processes.

2000 ◽  
Vol 55 (12) ◽  
pp. 1103-1113 ◽  
Author(s):  
Hans Bock ◽  
K. Gharagozloo-Hubmann ◽  
M. Sievert

The π-hydrocarbons p-terphenyl and p-quaterphenyl are reduced to their dianions in aprotic solutions of different ethers at sodium metal mirrors. Single crystal structure determinations of the solvent-separated or solvens-shared contact ion multiples, [p-terphenyl⊖⊖ Na⊕(DME)2Na⊕DME]2, p-quaterphenyl⊖⊖ ][Na⊕(DME)3]2 and [p-quaterpheny⊖⊖( Na⊕(THF)3)2], prove the essential cation solvation by the chelating dimethoxyethane (DME) versus the bulky tetrahydrofuran (THF) ligands: The solution network of equilibria between solvent separated and solvent shared ion aggregates can be considerably and transparently modified by the ether solvent selected. In addition, the structures of the monomeric sodium salts reveal partly novel details of metal cation coordination by contacts Na⊕ ··· O as well as Na⊕ ··· Cπ such as in the dimeric sodium salt of p-terphenyl dianion, [(DME)2Na⊕ (terphenyl⊖⊖)(Na⊕ DME)(terphenyl⊖⊖)Na⊕ (DME)2].


1984 ◽  
Vol 34 ◽  
Author(s):  
Edward Fras ◽  
Edward Guzik ◽  
Antoni Karamara

ABSTRACTThe paper present the results of investigation into the directional solidification of Fe-C-Cr alloys containing about 30% Cr and various contents of carbon. The main types of the structure of these alloys were given and the zone of a coupled growth of the eutectic was determined as well as an effect of the growth rate on the interfacial distance λ and on the tensile strengthof these alloys. It was proved that the additions of titanium and cerium considerably reduce the distance λ and increase the tensile strength, which in the case of an Fe-Cr-C-Ce alloy can reach a value of about 3250 MPa. The alloys solidified in the form of bars and plates which also enabled the determination of an effect of angle between the axis of the carbide fibres and the direction of loading on the ultimate tensile strength. of these alloys.


Refractories ◽  
1990 ◽  
Vol 31 (3-4) ◽  
pp. 153-155
Author(s):  
O. V. Bakunov ◽  
E. P. Pakhomov ◽  
Yu. I. Chubarov

2019 ◽  
Vol 12 (1) ◽  
pp. 1-6 ◽  
Author(s):  
Muna K. Abbassa ◽  
Noor Alhuda B. Sharhan

This work is devoted toward optimization of the parameters of the friction stir processing (FSP) which effect on tensile strength of aluminium alloy AA6061-T6 of 6mm thick plate by applying a certain number of tests utilizing the Taguchi method. Design of experiment (DOE) has been applied for the determination of the most important parameters influencing ultimate tensile strength. FSP was achieved under three different rotation speeds (800,1000 and 1250) rpm, different transverse speeds (16,25 and 32) mm\min, and number passes(1,2 and 3)  in the same direction and tool tilt angle was 2°  with using threaded cylindrical pin profile.  The best FSP parameters were 1250 rpm and 32 mm\min and two passes. It was found that the higher hardness value was 75HV in stir zone center and then decreases toward the TMAZ, HAZ and the base metal


2009 ◽  
Vol 45 (3) ◽  
pp. 235-239 ◽  
Author(s):  
B. A. Rychkov ◽  
Zh. Y. Mamatov ◽  
E. I. Kondrat’eva

2017 ◽  
Vol 756 ◽  
pp. 80-87
Author(s):  
Anton Panda ◽  
Ema Nováková-Marcinčinová ◽  
Ľudmila Nováková-Marcinčinová ◽  
Tibor Krenický ◽  
Tadeusz Zaborowski

The article is focused on the aspects in samples production of sophisticated material – PLA - PolyLacticAcid, PLA plastic. The main part of the work focuses on experimental production and testing of PLA material - PolyLacticAcid plastic, printed on RepRap 3D device that works on the "open source" principle. The article presents the outcomes of test materials in the form of measurement protocols recorded in the software, the measured values ​​in a static tensile test, marked down in tables and shown in work graphs. The article describes selected and carried out tests of mechanical properties of PLA plastics extruded in different directions in this case carried out vertically by FDM rapid prototyping method of two PLA materials such as pure without additives blended with blue dye. The tests are mainly focused on the determination of ultimate tensile strength. Based on the results obtained, the samples made of two PLA materials were compared in the end to establish which produced PLA material sample is stronger. There are outputs in the form of logs, charts and tables that provide information about the executed tests and comparisons, which were made by the authors.


Author(s):  
Henry S. Slayter

Electron microscopic methods have been applied increasingly during the past fifteen years, to problems in structural molecular biology. Used in conjunction with physical chemical methods and/or Fourier methods of analysis, they constitute powerful tools for determining sizes, shapes and modes of aggregation of biopolymers with molecular weights greater than 50, 000. However, the application of the e.m. to the determination of very fine structure approaching the limit of instrumental resolving power in biological systems has not been productive, due to various difficulties such as the destructive effects of dehydration, damage to the specimen by the electron beam, and lack of adequate and specific contrast. One of the most satisfactory methods for contrasting individual macromolecules involves the deposition of heavy metal vapor upon the specimen. We have investigated this process, and present here what we believe to be the more important considerations for optimizing it. Results of the application of these methods to several biological systems including muscle proteins, fibrinogen, ribosomes and chromatin will be discussed.


Sign in / Sign up

Export Citation Format

Share Document