In-situ ZrB2-hBN ceramics with high strength and low elasticity
来源期刊：JOURNAL OF MATERIALS SCIENCE TECHNOLOG2020年第13期
论文作者：Ji Zou Guo-Jun Zhang Zheng-Yi Fu
文章页码：186 - 193
摘 要：ZrB2 ceramics with various hexagonal BN（hBN） additions up to 37 vol% were reactively densified by spark plasma sintering using powder mixtures containing ZrB2,ZrN and boron.ZrN-boron based additives effectively promoted the densification process,ZrB2 ceramics reached>99% relative density at 2000℃ and an applied pressure of 60 MPa with only 5 vol% in-situ formed hBN,whereas the relative density of pure ZrB2 was only 91.2% at the same conditions.Increasing thehBN contents,the morphology of hBN grains gradually changed from quasi-spherical to flake dominated,which has substantial influence on their mechanical properties.In-situ ZrB2-10 vol% hBN ceramics demonstrated high flexural strength of 597±22 MPa,relatively low Young’s modulus of 406 GPa and good machinability,especially for the impressively large strain to failure(1.47 × 10-3) which is superior to most of their counterparts in the ZrB2 based particulate reinforced ceramics.
Ji Zou1,2，Guo-Jun Zhang3，Zheng-Yi Fu1
1. State Key Laboratory of Advanced Technology for Materials Synthesis and Processing, Wuhan University of Technology2. School of Metallurgy and Materials, University of Birmingham3. State Key Laboratory for Modification of Chemical Fibers and Polymer Materials, Institute of Functional Materials, Donghua University
摘 要：ZrB2 ceramics with various hexagonal BN（hBN） additions up to 37 vol% were reactively densified by spark plasma sintering using powder mixtures containing ZrB2,ZrN and boron.ZrN-boron based additives effectively promoted the densification process,ZrB2 ceramics reached>99% relative density at 2000℃ and an applied pressure of 60 MPa with only 5 vol% in-situ formed hBN,whereas the relative density of pure ZrB2 was only 91.2% at the same conditions.Increasing thehBN contents,the morphology of hBN grains gradually changed from quasi-spherical to flake dominated,which has substantial influence on their mechanical properties.In-situ ZrB2-10 vol% hBN ceramics demonstrated high flexural strength of 597±22 MPa,relatively low Young’s modulus of 406 GPa and good machinability,especially for the impressively large strain to failure(1.47 × 10-3) which is superior to most of their counterparts in the ZrB2 based particulate reinforced ceramics.
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