Search results for "Metallurgy"

Mechanically Activated Self-Propagating High Temperature Synthesis (MASHS) Applied to the MoSi<sub>2</sub> and FeSi<sub>2</sub&g…

1999

High Temperature Sulfidation of Al-and Mo-Modified 310 Stainless Steel

1997

Le comportement a la sulfuration d'aciers inoxydables 310 modifies (avec differentes quantites de Mo et Al jusqu'a 10 at%) a ete etudie entre 700-900°C sous pressions de soufre egales a 0.01 et 0.1 atm. La cinetique de corrosion de l'acier suit la loi parabolique et diminue quand la quantite de Mo et Al augmente. Les couches formees sur les aciers sont complexes et constituees de deux sous-couches. La couche externe est composee de sulfure de fer (avec du chrome dissous), de (Fe , Ni) 9 S 8 et de sulfures de chromes (Cr 2 S 3 /Cr 3 S 4 avec du fer dissous), tandis que la couche interne est un melange de plusieurs phases: Cr 2 S 3 /Cr 3 S 4 , Fe 1.25 Mo 6 S 77 , MOS 2 , Al 0.55 Mo 2 S 4 et F…

Photoelectrochemistry in corrosion studies: achievements and perspectives

1995

Atomic Structure and Mechanical Behaviour of Passive Film Formed on Stainless Steels

1995

Electrochemical characterization of natural gold samples using the voltammetry of immobilized particles

2017

The application of the voltammetry of immobilized particles for characterizing natural gold samples from different geological settings and dating vein deposits is described. This is based on recording characteristic electrochemical oxidation signatures of gold and silver following the attachment of metal sub-microsamples to graphite electrodes. Keywords: Electrochemistry, Gold, Mineralogy, Placer deposits, Vein deposits, Nuggets

Electrochemical discrimination of manufacturing types of pottery from Magna Mater Temple and Fora of Nerva and Caesar (Rome, Italy)

2018

Abstract The voltammetry of immobilized microparticles (VIMP) methodology is applied to a series of pottery samples from the Roman sites of Nerva's Forum (second half of 9th-early 11th A.D), Caesar's Forum (second half of 9th-early 11th A.D) and Magna Mater Temple (III century). The VIMP sampling applied to voltammetric and electrochemical impedance spectroscopy (EIS) measurements was applied by the first time to acquire archaeometric information on archaeological pottery. VIMP measurements using pressed sample pellets on gold electrodes in contact with air-saturated 0.10 M H2SO4 have permitted to detect voltammetric signals for the reduction/oxidation of Fe and Mn minerals as well as catal…

Comparative assessment of surface roughness produced by hard machining with mixed ceramic tools including 2D and 3D analysis

2005

Abstract This paper provides a new comprehensive analysis of part surface finish in continuous dry turning of a hardened construction steel when using mixed alumina cutting tools. Consequently, the surface profiles (2D arragement) and surface microstereometries (3D arragement) generated during different hard part turning operations on a 40H low chromium alloy steel (equivalent to AISI 5140 or DIN 41Cr4), heat treated to the hardness of about 60 HRC, were evaluated. As a result, this paper aggregates the multi-parameters characterization of the surface roughness with the machined surface structure obtained at the three selected feed rates and constant cutting speed of 100 m/min. Results show…

Integrated analytical methodologies for the study of corrosion processes in archaeological bronzes

2011

Abstract The investigations on structure and micro-chemical composition of archaeological metal alloys are needed in archaeometry. The aim of this study is devoted both to acquire information about their provenance and production technology, and to improve our understanding about the corrosion processes. In this paper we present the study of the corrosion phenomena of bronze samples, laboratory-made according to binary, ternary and quaternary alloys typical of Roman archaeometallurgical production through an integrated methodology based on the use of non or micro invasive physical techniques. Among the analysed samples, two were artificially aged through burial in the archaeological site of…

Influence of Feed on Tool Life of Sintered Carbide in Interrupted Cutting

1986

The paper examines the influence of feed on the mean life of sintered carbide inserts in turning UNI 48S5 steel in interrupted cutting conditions.

Computer simulation of metal flow in the hot upsetting of a high-strength aluminium alloy

1993

Abstract The effects of metal-working temperature on the hot axisymmetric upsetting of AA 7012 aluminium alloy were investigated in the temperature range of from 250 to 400°C, at a strain rate of 4 s −1 . The material behaviour was studied by means of simulative methods based on the analysis of torsion-test results which have shown that when the strain increases, the flow stress increases to a peak value and then decreases to a fracture value. Furthermore, the flow stress decreases with decreasing strain rate and with increasing temperature. Constitutive equations, describing accurately the hot deformation behaviour of the material, were defined and used subsequently in a numerical model th…