Search results for "engineering.material"
showing 10 items of 2352 documents
Atomic Structure and Mechanical Behaviour of Passive Film Formed on Stainless Steels
1995
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…
Reactive sputtering of nanostructured multilayer coatings and their tribological properties
1999
Abstract The present study describes and reports on reactive sputtering of nanostructured multilayer coatings. A 3 μm coating for instance may contain up to a few thousand bilayers of two different film materials, and in order to achieve this, a substrate holder rotates through two different sputtering zones in an Alcatel SC 650 sputtering equipment with metal and carbon cathodes operating concurrently in the so-called side-by-side configuration. In reactive sputtering of nitrides, reactive nitrogen was controlled very accurately in order to establish controllable points on a total sputtering pressure versus nitrogen flow curve. Nanostructured multilayer coatings of the type MeN/C–N were de…
Microstructural and magnetic characterization of fly ash from Kolaghat Thermal Power Plant in West Bengal, India
2011
Abstract This paper reports on the physical nature of the fly ash sample of the Kolaghat Thermal Power Plant, India with an emphasis on its ultrafine nature. This paper also deals with the measurement of the magnetic properties of the fine particles of the fly ash sample. Particle sizes of this fly ash sample estimated from the SEM images lie within 0.16–5.50 μm, and the EDX spectral analysis indicates the presence of O, Al, Si, C, Fe, Mg, Na, K and Ti in this sample. From the XRD study, it is found that physical nature of conglomeration in the fly ash is crystalline and the major components are mullite (Al 6 Si 2 O 13 ) and quartz (SiO 2 ). Additionally, the presence of hematite, microclin…
Numerical support for laser welding of zinc-coated sheets process development
2002
Abstract A lap welding process for zinc-coated sheets has been developed with the help of numerical simulations. This process has been improved and is now compatible with industrial requirements. The zinc boiling point (1180 K) is lower than the steel melting point (1800 K). Consequently, a violent boiling of zinc in melted steel produces serious defects in the seam. To get round this difficulty, we choose to consider a two-spots process: the first spot vaporizes the zinc coating at the interface; the second one welds the sheets. Previously, we develop a numerical model that permits a process parameters choice and limits the plan of experimentations. The zinc ablation spotlight shape is cho…
Ionic Nitriding of Certain Parts Protected on Nonfunctional Surfaces With Special Paints. Electric Energy Consumed
2021
The experimental researches on the promotion of new technologies for the local protection of metallic parts against plasma nitriding, led to two types of special paints for protection in ionic nitriding, paints elaborated on the basis of copper lamellar powder in combination with magnesium oxide and carbon tetrachloride. In the created context, it was considered that the elaborated paints could be used not only for preventing the hardening during ionic nitriding of certain technological surfaces of the parts on which they are applied, but also for coating certain nonfunctional surfaces, their degasification taking such a long time. These nonfunctional areas could be: surfaces resulted from …
Use of Diamond Films in Organic Electrosynthesis
2011
Improvement of flame spraying PEEK coating characteristics using lasers
2011
Flame spraying is frequently used for PEEK coatings elaboration on metallic surfaces. However, this process has a certain number of limitations particularly considering the quality of the coatings like high porosity or low interfacial adherence. For that reason a thermal post-processing is often necessary. From all of the processes which can be used (flame, oven, etc.), laser can be an interesting technology. Then, the aim of this study is to analyse the dependence of the morphological structure (compactness) and the adherence of the flame sprayed PEEK coatings to the stainless steel (304L) and aluminium alloy (AA2017) substrates on laser parameters. Moreover, the influence of the laser bea…
Comparison of Cu-B Alloy and Stainless Steel as Electrode Material for Microbial Fuel Cell
2019
The microbial fuel cell (MFC) is a technical devices that electricity produces during wastewater treatment. One of the problems of MFCs is a low current density. Thus, it is necessary to search for new electrodes for MFC. The comparison of Cu-B alloy and stainless steel as catalyst for MFCs cathode is presented in this paper. The research included measurements of the concentration of COD, NH4+ and NO3− in three types of reactors: without aeration, with aeration and with using a MFC (with Cu-B and stainless steel cathode). It has been shown that effectiveness of MFC with Cu-B electrode is higher than effectiveness of MFC with stainless steel electrode.