Effects of wet and dry milling conditions on properties of mechanically alloyed and sintered W-C and W-B4C-C composites

Authors: Ünal, N.1; Öveçoğlu, M.L.2

Source: Powder Metallurgy, Volume 52, Number 3, September 2009 , pp. 254-265(12)

Publisher: Maney Publishing

Key:
Free Content - Free Content
New Content - New Content
Subscribed Content - Subscribed Content
Free Trial Content - Free Trial Content

Abstract:

Tungsten based W-1C and W-2B4C-1C (wt-%) powders synthesised by mechanical alloying (MA) for milling durations of 10, 20 and 30 h, in wet (ethanol) and dry conditions, were characterised. X-ray fluorescence spectroscopy investigations revealed Co contamination which increased with increasing milling time during wet milling. X-ray diffraction investigations revealed the presence of W and WC phases in all powders, Co3C intermetallic in the wet milled W-1C powders and W2B intermetallic phase in both wet and dry milled W-2B4C-1C powders. As blended and MA processed powders were consolidated into green compacts by uniaxial cold pressing at 500 MPa and solid phase sintered at 1680°C under hydrogen and argon atmospheres for 1 h. X-ray diffraction investigations revealed the presence of W2C intermetallic phase in sintered composites produced from both wet and dry milled W-1C powders and the W2B intermetallic phase in sintered material from the wet milled W-2B4C-1C powder. Sintered composites from wet milled powders showed relative densities >91%, with the maximum density of 99·5% measured for the sintered 30 h wet milled W-2B4C-1C composites. Microhardness values for the wet milled W-1C and W-2B4C-1C composites were 2-2·5 times higher than those for dry milled composite powders. A maximum hardness value of 23·7±2·1 GPa was measured for the sintered W-2B4C-1C composite wet milled for 20 h.

Keywords: MECHANICAL ALLOYING; TUNGSTEN; BORON CARBIDE; SINTERING; CHARACTERISATION

Document Type: Research article

DOI: 10.1179/003258909X12490463446434

Affiliations: 1: Department of Metallurgical and Materials Engineering, Faculty of Chemistry-Metallurgy, Istanbul Technical University, Maslak, 34469 Istanbul, Turkey;, Email: nil_unal@yahoo.com 2: Department of Metallurgical and Materials Engineering, Faculty of Chemistry-Metallurgy, Istanbul Technical University, Maslak, 34469 Istanbul, Turkey

The full text electronic article is available for purchase. You will be able to download the full text electronic article after payment.

$51.00 plus tax      Refund Policy

 

OR

Back to top

Key:
Free Content - Free Content
New Content - New Content
Subscribed Content - Subscribed Content
Free Trial Content - Free Trial Content
Share this item with others: These icons link to social bookmarking sites where readers can share and discover new web pages.
Page Help Click here for Page Help
Shopping cart
Tools
Sign in






Need to register?
Sign up here
Text size: A | A | A | A