ISSN:
1662-0356
Source:
Scientific.Net: Materials Science & Technology / Trans Tech Publications Archiv 1984-2008
Topics:
Natural Sciences in General
,
Technology
Notes:
Mechanical Activation assisted Self-propagating High-temperature Synthesis in air(MA-SHS in air process) was successfully applied to the synthesis of the powder mixtures of ZrB2 andZrC containing Ta and Hf as a precursor of Ultra High Temperature Ceramic (UHTC) matrixcomposites. When the powder mixtures of (Ta or Hf+Zr)/B/C=2/2/1 (Ta or Hf/Zr=0/2, 0.1/1.9, 0.2/1.8,0.4/1.6) in molar ratio were mechanically activated (MA) by ball milling for 45-60 min and thenexposed to air, they self-ignited spontaneously and the self-propagating high-temperature synthesis(SHS) was occurred to form ZrB2 and ZrC. From these MA-SHS powders, the Ta, Hf-containingZrB2-ZrC composite compacts having a fine and homogeneous microstructure composed of 〈 5μm-sized grains were fabricated by spark plasma sintering (SPS) at 1800ºC. The mechanicalproperties of the composites evaluated by Vickers indentation method was improved by the additionof Ta and showed the values of Vickers hardness (HV) of 16.9 GPa and fracture toughness of 4.3MPa·m1/2
Type of Medium:
Electronic Resource
URL:
http://www.tib-hannover.de/fulltexts/2011/0528/01/42/transtech_doi~10.4028%252Fwww.scientific.net%252FAST.45.1041.pdf
Permalink