Sökning: "high-velocity compaction"

Hittade 5 avhandlingar innehållade orden high-velocity compaction.

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

3. 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

4. 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

5. 4. Biomaterial Components Prepared by Titanium Powder Technology

   Författare :Mikael Eriksson; Chalmers tekniska högskola; []
   Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; dental; coping; biomaterial; titanium-hydroxyapatite composite; crown; cold isostatic pressing; deformation; titanium powder; high velocity compaction; powder metallurgy;

   Sammanfattning : The main objectives of this work were twofold: First, to determine if a pressed-powder method could be used to fabricate titanium dental copings, and to line out what problems or benefits this new method would have. Second, to test if high velocity compaction of titanium powder could be used to form biomaterial components such as copings or dental implants. LÄS MER

7. 5. Processing Methods for Reaching Full Density Powder Metallurgical Materials

   Författare :Maheswaran Vattur Sundaram; Chalmers tekniska högskola; []
   Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; gas atomised powder; water atomised powder; high density powder metallurgical materials; high density; master alloys; liquid phase sintering; sintering; high velocity compaction; hot isostatic pressing; additive manufacturing;

   Sammanfattning : Powder metallurgy (PM) is one of the most cost effective methods for manufacturing structural components with complex shapes. Utilisation of the metal powder to shape the components allows to minimise material waste and increase energy efficiency. LÄS MER