HUANG Qizhong
,
YANG Qzaoqin and WU Lijun(Powder Metallurgy Research institute
,
Central Sonth University of Technology
,
Changsha 410083
,
China Materials Research and Test Center
,
Hnnan University
,
Changsha 410082
,
ChinaLab. of Atomic Imaging of Solids
,
Institute of Metal Research
,
Chinese Academy of Sciences
,
Shenyang110015
,
ChinaState Key Laboratory for Corrosion and Protection
,
Institute of Corrosion and Protection of Metals
,
Chinese Academy of Sciences
,
Shenyang 110015
,
China)Manuscript received 4 August 1995
,
in revised form 6 April 1996
金属学报(英文版)
A Preliminary study of the effect of silicon additive on the structure and properites of C-B_4C-SiC composite was conducted. A liquid Phase has formed and the liquid Si reacts with C to form SiC at the grain boundary when sintering, which accelerates the sintering process and retards the grain growth. Consequently, the density and strength of the composite increase markedly. And the increase in the density increases the oxidation resistance and decreases the specific resistance of the composite. Furthermore,the C-B_4 C-SiC composite has good heat-shock resistance. The phenomena may be dueto the strengthening and toughening of microcracks.
关键词:
:Si additive
,
null
,
null
ZHAO Lihua
,
WU Lijun
,
HUANG Qizhong
,
YANG Qiaoqin 1)(Material Research and Test Center
,
Hunan University
,
Changsha
,
China)2)(Powder Metallurgy Research Institute
,
Center-South University of Technology
,
Changsha
,
China)3)(Laboratory of Atomic Imaging of Solids
,
Institute of Metal Research
,
Chinese Academy of Science
,
Shenyang
,
China)Manuscript received 18 April 1995
金属学报(英文版)
C-B4C-SiC composites with silicon additive obtained by the hot press sintering method are studied by means of transmission electron microscopy(TEM).When the specimens are heated to 1800℃,their structure does not change.When the specimens are heated to 2000℃,carbon begins to graphitize. Moreover,two monoclinic phases are observed.One monoclinic phase named as the M phase belongs to C-center monoclinic lattice with a=0.90nm,b=0.59nm,c=0.54nm and β=119.3°.The other monoclinic phase named as the Ml phase also belongs to C-center monoclinic lattice but with a=0.85nm,b=0.49nm,c=0.53nm and β=123.6°.
关键词:
:C-B_4C-SiC composite
,
null
