Type

Journal Article

Authors

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

Subjects

Engineering

Topics
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

1
Denis P. Dowling
University College Dublin
Total Publications: 50