Sökning: "Sintering"

Visar resultat 11 - 15 av 247 avhandlingar innehållade ordet Sintering.

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

   Författare :Dimitris Chasoglou; Chalmers tekniska högskola; []
   Nyckelord :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;

   Sammanfattning : 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. LÄS MER

3. 12. Studies of catalyst sintering during operating conditions

   Författare :Pooya Tabib Zadeh Adibi; Chalmers tekniska högskola; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; nanoparticle sintering; operando spectroscopy; catalyst deactivation; indirect nanoplasmonic sensing; platinum; sintering kinetics;

   Sammanfattning : The damaging effect of pollutants from exhaust gas of combustion engines on the human health and the environment is well recognized. Since the 70s, the three-way catalytic converter (TWC) has substantially improved the urban air quality by simultaneous conversion of CO, NOx and unburned hydrocarbons to O2 , N2 , CO2 and H2O. LÄS MER

4. 13. In situ Studies of Platinum Catalyst Sintering

   Författare :Pooya Tabib Zadeh Adibi; Chalmers tekniska högskola; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; nanoparticle sintering; indirect nanoplasmonic sensing; operando spectroscopy; transmission electron microscopy; platinum; catalyst deactivation; sintering kinetics;

   Sammanfattning : The damaging effect of pollutants from combustion engine exhaust on human health and environment is well recognized. Since the 70s, the three-way catalytic converter (TWC) has substantially improved the urban air quality by simultaneous conversion of CO, NOx and unburned hydrocarbons to O2, N2 and H2O. LÄS MER

5. 14. Sintering of nickel catalysts in the presence of NH3/H2

   Författare :Johan Lif; Chalmers tekniska högskola; []
   Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; NATURVETENSKAP; NATURAL SCIENCES; stabilisation; hydrogen; nickel; ammonia; alumina; sintering; DFT calculation; catalyst deactivation;

   Sammanfattning : Supported metal catalysts are used in many important industrial processes, where amination of alcohols is one example. The exposure of the supported metal catalyst to reaction conditions results usually to a decrease in catalytic activity, by for instance thermal degradation. LÄS MER

7. 15. Sintering of water-atomized iron and low-alloyed steel powder

   Författare :Johan Wendel; Chalmers tekniska högskola; []
   Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; reduction kinetics; water-atomized steel powder; water-atomized iron powder; sintering; oxide reduction; surface analysis; dilatometry; surface chemistry; thermogravimetric analysis;

   Sammanfattning : Iron and steel powder grades are extensively used in the powder metallurgy (PM) industry for manufacturing of ferrous structural components, with a major customer in the automotive industry. The powder grades are predominantly manufactured by water-atomization, yielding powder particles with highly irregular morphology and good compressibility, making the powder ideal for the conventional press-and-sinter manufacturing route. LÄS MER