Sökning: "Hard Coatings"

Visar resultat 21 - 25 av 81 avhandlingar innehållade orden Hard Coatings.

1. 21. Ab initio and phenomenological modeling of materials related to CVD hard coatings

   Författare :Axel Forslund; Andrei V. Ruban; Paul Erhart; KTH; []
   Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Teknisk materialvetenskap; Materials Science and Engineering;

   Sammanfattning : This thesis describes the work based on two different tools in computational materials science: a first-principles approach, namely that of density functional theory, and the CALPHAD approach.These two methods were used in this work to calculate properties of materials related to hard coatings, in particular coatings produced with chemical vapor deposition for the purpose of wear protection in cutting tools. LÄS MER

3. 22. Multiscale materials design of hard coatings for improved fracture resistance and thermal stability

   Författare :Phani Kumar Yalamanchili; Magnus Odén; Naureen Ghafoor; Emilio Jiménez-Piqué; Jon Molina; Linköpings universitet; []
   Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; NATURVETENSKAP; NATURAL SCIENCES;

   Sammanfattning : Physical vapor deposited hard coatings comprised of cubic (c) transition metal (TM)-Al-N, and (TM)-Si-N are the current workhorse materials for a large number of metal cutting and wear resistant applications to fight against the extreme conditions of temperature and stress simultaneously. In spite of a high degree of sophistication in terms of material choice and microstructural design, a lower fracture resistance and limited thermal stability of the coatings remains a technological challenge in the field. LÄS MER

4. 23. Surface nanomechanical properties of hydrogels and coatings

   Författare :Gen Li; Per M. Claesson; Jan van Stam; KTH; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Nanomechanical properties; nanotribology; nanowear; poly-HEMA; poly-NIPAm; Cellulose nanocrystals; AFM; Kemi; Chemistry;

   Sammanfattning : Characterizing mechanical and wear properties at the nanometer scale emerged as a fascinating and challenging topic in the last decades due to recognition of many interesting and unusual properties of nanomaterials. Due to recent developments of the atomic force microscopy (AFM) technique, it is now possible to measure nanomechanical properties and topography simultaneously, as well as performing and evaluating wear measurements at the nanometer scale. LÄS MER

5. 24. Sputtering and Characterization of Complex Multi-element Coatings

   Författare :Erik Särhammar; Tomas Nyberg; Ulf Jansson; Urban Wiklund; Gustaf Sjöblom; Uppsala universitet; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; thin film; coating; magnetron sputtering; modelling; tribofilm; tungsten disulphide;

   Sammanfattning : The thin film technology is of great importance in modern society and is a key technology in wide spread applications from electronics and solar cells to hard protective coatings on cutting tools and diffusion barriers in food packaging. This thesis deals with various aspects of thin film processing and the aim of the work is twofold; firstly, to obtain a fundamental understanding of the sputter deposition and the reactive sputter deposition processes, and secondly, to evaluate sputter deposition of specific material systems with low friction properties and to improve their performance. LÄS MER

7. 25. Microstructural investigation of CVD TiAlN, TiN and WN coatings

   Författare :Ren Qiu; Chalmers tekniska högskola; []
   Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; TEM; XEDS; TiN; SEM; APT; TiAlN; coating growth; EBSD; WN; CVD;

   Sammanfattning : High speed machining of workpiece materials puts extreme thermal and pressure loads onto the cutting tool inserts, which thus must possess both high hardness and good toughness. Nowadays, most cutting tools are made of cemented carbide substrates that are coated with wear-resistant coatings. LÄS MER