Journal Article


Denis P. Dowling
Alan Hynes
Greg Byrne
Aidan Breen
Barry Twomey



x ray diffraction microwave plasma sintering flexural strength diamond processing mechanical behaviour wear metal matrix composites mmcs

Rapid discharge sintering of nickel-diamond metal matrix composites (2011)

Abstract In this study rapid discharge sintering (RDS) and furnace sintering of nickel–diamond metal matrix composites (MMCs) is compared. Nickel–diamond powder composites (80–20% by weight respectively) were uniaxially pressed into 20 mm discs at compaction pressures of 100, 200 and 300 MPa. Discharge sintering was carried out using a microwave plasma formed with hydrogen and hydrogen/nitrogen as the discharge gases and tube furnace sintering carried out in a argon or a hydrogen/nitrogen (3:1) atmosphere. Discs pressed to 300 MPa were treated at both 850 and 1000 °C. The properties of the sintered nickel–diamond composites were characterized using density, approximate flexural strength, hardness, wear resistance, scanning electron microscopy (SEM) and X-ray diffraction (XRD). The RDS samples sintered at 1000 °C achieved the maximum approximate disc flexural strength of 473 MPa within a 20 min treatment time compared with 6 h for furnace sintered samples. Samples sintered using the RDS technique exhibited increased hardness values and a finer nickel matrix over furnace sintered samples. Using the RDS technique it has been possible to process nickel–diamond MMCs without oxidation or graphitisation at temperatures above 900 °C. Minimal diamond destruction was observed during abrasive wear testing of the RDS samples compared with damage and pull-out observed for furnace sintering.
Collections Ireland -> University College Dublin -> Mechanical & Materials Engineering Research Collection
Ireland -> University College Dublin -> College of Engineering & Architecture
Ireland -> University College Dublin -> School of Mechanical and Materials Engineering

Full list of authors on original publication

Denis P. Dowling, Alan Hynes, Greg Byrne, Aidan Breen, Barry Twomey

Experts in our system

Denis P. Dowling
University College Dublin
Total Publications: 50