Sökning: "surface transformation"

Visar resultat 1 - 5 av 253 avhandlingar innehållade orden surface transformation.

1. 1. ROLE OF SURFACE OXIDES IN SINTERING OF CHROMIUM-ALLOYED STEEL POWDER

   Författare :Henrik Karlsson; Chalmers tekniska högskola; []
   Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; water atomisation; surface analysis; sintering; chromium-alloyed steel.; Powder metallurgy; surface reactions; surface; surface oxide; SEM; XRD; AES; XPS;

   Sammanfattning : During water-atomisation and handling of steel powder the surface inevitably oxidises. The surface bound oxide is an important factor in the processing of powder metallurgical (PM) steels, especially in case the powder contains elements forming stable oxides, such as Cr, Mn, and Si. LÄS MER

3. 2. Running-in of gears - surface and efficiency transformation

   Författare :Mario Sosa; Ulf Olofsson; Stefan Björklund; Ulf Sellgren; Jorge Seabra; KTH; []
   Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; running-in; surface transformation; efficiency; gears; ground; superfinished; Machine Design; Maskinkonstruktion;

   Sammanfattning : With ever shorter development times and market demands on overall system performance such as efficiency, reliability and low maintenance, accurate predictive tools are necessary and gear drives prove to be no exception. All these characteristics have an impact on a process which has remained a riddle: running-in. LÄS MER

4. 3. Surface Integrity of Case-hardened Gears - with Particular Reference to Running-in and Micropitting

   Författare :Dinesh Mallipeddi; Chalmers tekniska högskola; []
   Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; surface chemistry; residual stresses; surface asperities; micropitting; running-in; Gears; plastic deformed regions PDR ; deformation bands;

   Sammanfattning : A gearbox with gears of different sizes is part of a vehicle transmission system and plays an important part in transmitting the engine power to the wheels. The efficient energy transmission highly relies on the performance of gears. Together, the mesh efficiency and durability determines the performance of gears. LÄS MER

5. 4. Investigation of Surface Formation in As-Cast and Homogenized 6xxx Aluminium Billets

   Författare :Nazlin Bayat; Torbjörn Carlberg; Håkan Olin; Yanjun Li; Mittuniversitetet; []
   Nyckelord :DC casting; surface segregation; surface defects; intermetallic phase; phase transformation; homogenization;

   Sammanfattning : The direct chill (DC) casting technique to produce billets for extrusion and ingots for rollingwas developed in the 1930s. The principle, which is still valid, is a two-stage cooling with a primary cooling at a mould surface followed by water spraying directly on the surface. LÄS MER

7. 5. 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