|
Editorial
office and administration: Editura
Ştiinţifică F.M.R.,
Calea Griviţei, nr. 83, sector 1,
O.P.12, cod 010705, Bucharest, ROMANIA Tel.: +(40)-1-310 71 38, +(40)-1-0722 665 071 Fax: +(40)-1-310
71 38 E-mail: redactia@metalurgia.ro www.metalurgia.ro Readers
from abroad can subscribe through Editura Ştiinţifică F.M.R. Contul
EDITURII ŞTIINŢIFICE F.M.R.: Lei: BCIŢ, Sucursala Rosetti, Bucureşti Cod
IBAN: RO55 CBIT 4260 1037 4300 1000 USD: BCIT
Sucursala rosetti,
Bucureşti Cod
IBAN: RO21 CBIT 4260 1037 4300 2000 Euro:
BCIT Sucursala rosetti,
Bucureşti Cod
IBAN: RO84 CBIT 4260 1037 4300 3000 Banca Comercială
Ion Ţiriac, ROSETTI BRANCH, Bucharest,
Romania Copyright
© 2006 editura
Ştiinţifică F.M.R.-Bucharest,
Romania The
copyright of parts from this publication is allowed with the written
agreement of the editor. The
price for annual subscription:
USD 120
EURO 140 |
Metalurgia INTERNATIONAL (magazine set-up
in 1995) English version,
published by romanian metallurgical
foundation Honorary president
of scientific
publishing house f.m.r. Dr. ec. Lepădatu v. gheorghe
(2006) no.4 romanian metallurgical foundation Scientific publishing house
|
||
|
Honourary
Staff (in alphabetical order) bensabra
hakim (algeria), chabour
salem (algeria), gencang yang
(china), R. I. IMRI
(TECHNICAL |
|||
|
romanian metallurgical foundation Scientific publishing house scientific board staff Professor NICOLAE AVRAM
Ph. D. professor Scorţea
Costin Ph. D Managing Director: Editor-in-chief: Professor Scorţea
Costin Ph. D. editorial board: Prof. bejan Mircea Ph. D Prof. cănănău nicolae Ph. D Prof. GĂLUŞCĂ
DAN GELU Ph. D Prof. hepuţ teodor Ph. D Prof. TODERIŢA
NEMEŞ Ph. D Prof. MARIA
NICOLAE Ph. D Prof. Ripoşan Iulian Ph. D Prof. samoilă Corneliu Ph. D Prof. SCORŢEA
COSTIN Ph. D Prof. SIMITI IOAN VIDA Ph. D Prof. SOFONEA GALAFTION Ph. D Prof. Şaban Rami Ph. D Manager Scientific Publishing House F.M.R.: eng. Florentina
Brβnduşa Scorţea |
Contents Issn 1582 2214 Cojocaru
Mihai, Cecilia Tarcan, Gostin Flaviu, Coman Cristi, Chis Mircea: Functional gradient hard alloys intended
for mining industry
. 5 Agop Maricel, Vizureanu Petrică, Corina Marin, Iuliana Oprea: Superconductivity by means of the
scale relativity theory .......................................................................................
13 Chichernea ? FOSECO
Turbostop system reference list
...
. I - II ? Press
release
..
...
.
.....................
III IV ? Intrenational
events
.
V VI
? New books,
published by romanian metallurgical
foundation... VII - VIII |
||
abstract
metalurgia International 4/2006
|
D.C.: 669.018.25 Key
words: functional gradient hard
alloys; metallic carbides; hard alloys sintering powder metallurgy functional
gradient elements; mechanical tools; mining rotating tools Cojocaru Mihai, Cecilia
Tarcan, Gostin Flaviu, Coman Cristi, Chis Mircea: Functional
gradient hard alloys intended for mining industry Metalurgia International (vol. XI), no.4, 2006,
p. 5 Production of metallic carbides by Powder Metallurgy
(PM) is on high demand, as a stable attraction on PM market. Increasing
tools life, mechanical and machining process productivity can be achieved by
improving the actual performances of the main types of materials used in tool
fabrication i.e. sintered hard alloys. Controlled modifications of chemical
and phase composition on classical materials accomplish these objectives,
when new solution of functional gradient hard alloy materials (FGHAM) based
on sintered techniques are used. The paper introduces the method of
control/modification of chemical and phase composition on hard Tungsten
carbides WC based alloys, in the presence of a functional gradient element
i.e. Cobalt to induce the complex of properties required by the excessive
stresses and vibration of rotating/hammer mining equipment. New class of
materials have been used in this research to achieve the most representative,
reliable, and performing mechanical mining tool. A series of comparative test
results, in comparison with literature are presented, certifying its high
class superiority. D.C.: 537.311.3 Agop
Maricel, Vizureanu Petrică, Corina Marin, Iuliana Oprea: Superconductivity by
means of the scale relativity theory Metalurgia International (vol. XI), no.4, 2006, p. 13 One gets
some interesting results if introduces the hydrodynamic formulation of scale
relativity theory, for a coherent quantum fluid, into the TDGL equation,
which describes superconductivity. The London gauge and the zero momentum of
the Copper pairs (i.e. the London equations) arise naturally from the
imaginary parts of the computed system. One gets a particular relation
between the diffusion coefficient,
the (dimensionless) friction coefficient and the
(dimensionless) Ginzburg-Landau parameter which yields a new natural gauge
for the TDGL equation (as postulated by some authors). If one makes the value
of the real velocity of the Copper pairs to go to zero, the imaginary
velocity of the pairs becomes real. The subquantic potential gets a simple
expression and is proportional to the density of the Copper
pairs. Moreover, it can be
stated that the |
superconductor under special
circumstances acts like a subquantic medium energy accumulator. D.C.: 621.744.072 Key
words: foundry equipment, crusher,
3D modelling Chichernea Metalurgia
International (vol. XI), no.4, 2006, p. 30 Going beyond classical design models of equipment in
general and foundry equipment in particular may lead to a spectacular leap in this field. This
dose not imply the complete elimination of what has been achieved to date,
but a continuation of the stage of classical design by applying modern 3D computer aided design methods. Currently,
give the large range of available 3D modelling and designing software, the
work of the designing engineer can reach 80-90% efficiency, with results
close to realty. D.C.: 669.7 Key
words: metal foams, foaming agent, temperature, time Metalurgia
International (vol. XI), no.4, 2006, p. 35 The powder compact melting technique for aluminium
foam production as practised today accepts a certain mismatch between foaming
agent decomposition and matrix alloy melting temperatures. This mismatch is
believed to influence the pore structure in an unfavourable way. Adjustment of TiH2 decomposition as well
as liquidus and solidus temperatures of matrix alloys can be used to
counteract it. Effects of TiH2 thermal are investigated using
thermal analysis. TiH2 variants gained via annealing treatments
were used to produce aluminium foam precursor materials. D.C.: 669.7 Key words: metal foams, matrix alloys, foaming agent,
temperature, time Metalurgia
International (vol. XI), no.4, 2006, p. 39 As
matrix for these specimens, aluminium based alloys with low liquidus and
solidus temperatures were selected. Alloy systems considered include
established combinations of aluminium with Cu, Mg, Si and Zn as well as
special quaternary mixtures of these elements. First examinations presented
include thermal analysis of alloys as well studies on expansion vs. time and
temperature relationships of precursor material based on new alloys and
foaming agent variants. |
|
Copyright © 2006 The f.m.r. scientific publishing house,
accredited by the
romanian council for universitary research |
|
