Search for dissertations about: "surface oxide characteristics"

Showing result 1 - 5 of 100 swedish dissertations containing the words surface oxide characteristics.

2. 1. Surface Characteristics of Water Atomized Pre-alloyed Steel Powders and their effect on Sintering

   Author : Dimitris Chasoglou; Chalmers tekniska högskola; []
   Keywords : TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; spinel oxides; sintering; Cr-pre-alloyed powder; reduction; sintering atmosphere; surface oxide; fractography; XPS; oxidation; AES; EDX; carbothermal reaction; SEM; Powder metallurgy;

   Abstract : Powder Metallurgy (PM) is an efficient method, in terms of cost and raw material utilization, for the production of structural parts that have strict dimensional tolerances and complex geometries. In the common processing route, steel powder is fabricated by water atomization and then pressed and sintered into the final component. READ MORE

4. 2. Surface Chemical Characteristics of Chromium-alloyed Steel Powder and the Role of Process Parameters during Sintering

   Author : Dimitris Chasoglou; Chalmers tekniska högskola; []
   Keywords : TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; carbothermal reaction; sintering atmosphere; depth profiling; XPS AES; HR SEM EDX; water atomized powder; surface coverage; reduction oxidation; PM steels; sintering; Cr-Mn-spinel oxides; surface oxides;

   Abstract : Powder Metallurgy (PM) is a cost efficient method suitable for sustainable production of structural parts that have strict dimensional tolerances and complex geometries. It has been a common practice to utilize Ni and Cu as alloying elements in PM steels, but the high and fluctuating prices of Ni and the concerns around it associated with health hazards as well as the difficulty in recycling Cu lead the PM industry to search for effective alternatives such as Cr and Mn. READ MORE

5. 3. Dynamic Wetting of Solid Surfaces, Influence of Surface Structures and Surface Active Polymers

   Author : Stina Gerdes; Fysikalisk kemi; []
   Keywords : NATURVETENSKAP; NATURAL SCIENCES; Physical chemistry; stick-slip; Wilhelmy plate; block copolymers; surface active polymers; surface channels; spreading; contact angles; dynamic wetting; surface structures; Fysikalisk kemi;

   Abstract : The effect of surface structures on the dynamics of wetting was investigated through measurements of the dynamic contact angle and spreading velocity of oil droplets spreading over surfaces with parallel and gridlike V-shaped channels. A rim of liquid was observed to spread out in the channels ahead of the dropfront after a short time of spreading (seconds). READ MORE

6. 4. Effect of surface characteristics on cellular adherence and activity

   Author : Marjan Dorkhan; Malmö högskola; []
   Keywords : MEDICIN OCH HÄLSOVETENSKAP; MEDICAL AND HEALTH SCIENCES; Bacteria; microbial biofilm; dental implant; streptococci; oral bacteria; salivary pellicle; early colonizers; titanium oxide; microbial activity; oral keratinocytes; gingival fibroblasts; cell attachment; surface modification; anodic oxidation; anatase;

   Abstract : Ersättning av förlorade tänder med tandimplantat är numera en vanlig behandlingsmetod med generellt goda resultat. Antalet implantatsystem på den internationella marknaden har ökat kraftigt under senare år. READ MORE

7. 5. Metal Particles – Hazard or Risk? Elaboration and Implementation of a Research Strategy from a Surface and Corrosion Perspective

   Author : Klara Midander; Inger Odnevall Wallinder; Sannakaisa Virtanen; KTH; []
   Keywords : NATURVETENSKAP; NATURAL SCIENCES; NATURVETENSKAP; NATURAL SCIENCES; ferro-chromium alloy; metal particles; bioaccessibility; chemical speciation; dermal contact; surface oxide; in-vitro testing; chemical speciation; cu; copper; comet assay; intracellular; ultrafine; in vitro; A549; cytotoxicity; DNA damage; nanoparticles; particle characterization; artificial sweat; nickel release; nickel powder particles; particle loadings; release kinetics; surface area; copper release; powder particles; synthetic body fluids; simulation of interstitial lung conditions; skin contact; metal release; stainless steel; particles; test method; Surface and colloid chemistry; Yt- och kolloidkemi; Analytical chemistry; Analytisk kemi; Spectroscopy; Spektroskopi;

   Abstract : Do metal particles (including particles of pure metals, alloys, metal oxides and compounds) pose a hazard or risk to human health? In the light of this question, this thesis summarizes results from research conducted on metal particles, and describes the elaboration and implementation of an in vitro test methodology to study metal release from particles through corrosion and dissolution processes in synthetic biological media relevant for human exposure through inhalation/ingestion and dermal contact. Bioaccessible metals are defined as the pool of released metals from particles that potentially could be made available for absorption by humans or other organisms. READ MORE