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论文类型：期刊论文

发表时间：2014-10-01

发表刊物：MATERIALS & DESIGN

收录刊物：SCIE、EI

卷号：62

页面范围：199-204

ISSN号：0261-3069

关键字：ZrB2; Ceramic composite; Mechanical properties; Toughening mechanism

摘要：WC-doped ZrB2-ZrSi2 ceramic composites were fabricated by hot pressing at temperatures ranging from 1450 degrees C to 1550 degrees C. The influence of ZrSi2 content on the mechanical properties of the composites was investigated by means of three point bending test and single edge notched-beam test, respectively. The microstructure and phase composition were characterized by scanning electron microscope (SEM) and X-ray diffraction (XRD) analysis. The results revealed that: (i) the highest relative density was 99.5% for the composite fabricated at 1550 degrees C; (ii) the doping of WC refined the grain size and led to an anisotropic grain growth which was evidenced by the occurrence of elongated grains; (iii) the highest strength and fracture toughness were 585 MPa and 6.87 MPa m(1/2), respectively; (iv) the main toughening mechanism was considered as the pull out of elongated grains and the deflection of cracks. (C) 2014 Elsevier Ltd. All rights reserved.