Sökning: "Bruska Azhdar"

Hittade 3 avhandlingar innehållade orden Bruska Azhdar.

  1. 1. Improved high velocity cold copaction processing : polymer powder to high performance parts

    Författare :Bruska Azhdar; Sture Persson; Cornell Nicolescu; KTH; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; high-velocity compaction; powder polymers; polyamide-11; relaxation assist; compactibility; relative green density; morphology; pull-out; springback; Polymer chemistry; Polymerkemi;

    Sammanfattning : A uniaxial High-Velocity Compaction (HVC) process for polymer powder using a cylindrical, hardened steel die and a new technique with relaxation assist was tested with a focus on the compactibility characteristics and surface morphology of the compacted materials using various heights of relaxation assist device with different compacting profiles. Relaxation assist device was presented as a new technique to reduce springback, pull-out phenomenon and to improve the compaction process. LÄS MER

  2. 2. Novel Technique to Improve High-Velocity Cold Compaction : Processing of Polymer Powders and Polymer-Based Nanocomposite High Performance Components

    Författare :Bruska Azhdar; Bengt Stenberg; Leif Kari; Mikael Rigdahl; KTH; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; polymer powders; nanocomposites; high-velocity compaction; high-energy ball milling; Manufacturing engineering; Produktionsteknik;

    Sammanfattning : Compaction of polymer powders and polymer-based nanocomposites by uniaxial high-velocity cold compaction (HVC), by high-energy ball milling (HEBM) and using a novel technique, relaxation assists, was investigated with a focus on the process parameters, the compactibility characteristics, surface morphology and friction. The basic phenomena associated with HVC are explained and the general energy principle is introduced to explain the pull-out phenomenon, springback gradient, delay time, relative time of the pressure wave, and stick-slip phenomenon during the compaction process. LÄS MER

  3. 3. Discrete element simulation of elasto-plastic shock waves in high-velocity compaction

    Författare :Muhammad Shoaib; Leaf Kari; Bruska Azhdar; Wim Desmet; KTH; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; High-velocity compaction; Discrete element method; Plastic deformaiton; dynaimic loading; elasto-plastic shock wave; Friction; Adhesion; Physics; Fysik; Järnvägsgruppen - Ljud och vibrationer; Järnvägsgruppen - Ljud och vibrationer;

    Sammanfattning : Elasto-plastic shock waves in high-velocity compaction of spherical metal particles are the focus of this thesis which consists of four papers (A-D). The compaction process is modeled by a discrete element method while using elastic and plastic loading, elastic unloading and adhesion at contacts. LÄS MER