Mechanical Properties and Residue Stress of Four Kinds of ZrC Coatings Prepared by Chemical Vapor Deposition

doi:10.1007/s12204-012-1350-5

Abstract

Abstract: Four kinds of ZrC coatings with nearly the same thickness have been successfully prepared on graphite substrate by chemical vapor deposition (CVD) through controlling the ratio of inlet reacting gases. From backscattered electron images, it can be inferred that ZrCIII coating has the best tightness of all coatings. Meanwhile, line energy spectrum curve shows that zirconium and carbon elements distribute uniformly along the normal direction of the ZrCIII coating. As for varied microstructures, the coatings show different mechanical properties and residue stress. The strength and elastic modulus of ZrCIII coating were up to 89.57 and 1 192.5GPa, respectively. Those make it near the level of diamond. Value of residue tensile stress of ZrC+C composite coating was only 7.729MPa and that of ZrCIII coatings was 349.632 MPa. The strong combination of small-size grains in ZrCIII coating plays a decisive role to the best mechanical properties. However, strong misfit of lattice between ZrCIII coating and substrate can induce high residue stress.

Key words: zirconium carbide| coating| chemical vapor deposition (CVD)| microstructure

摘要： Four kinds of ZrC coatings with nearly the same thickness have been successfully prepared on graphite substrate by chemical vapor deposition (CVD) through controlling the ratio of inlet reacting gases. From backscattered electron images, it can be inferred that ZrCIII coating has the best tightness of all coatings. Meanwhile, line energy spectrum curve shows that zirconium and carbon elements distribute uniformly along the normal direction of the ZrCIII coating. As for varied microstructures, the coatings show different mechanical properties and residue stress. The strength and elastic modulus of ZrCIII coating were up to 89.57 and 1 192.5GPa, respectively. Those make it near the level of diamond. Value of residue tensile stress of ZrC+C composite coating was only 7.729MPa and that of ZrCIII coatings was 349.632 MPa. The strong combination of small-size grains in ZrCIII coating plays a decisive role to the best mechanical properties. However, strong misfit of lattice between ZrCIII coating and substrate can induce high residue stress.

关键词: zirconium carbide| coating| chemical vapor deposition (CVD)| microstructure

CLC Number:

TQ 134.1

SUN Weia* (孙威), XIONG Xianga (熊翔), LI Xiao-binb (李小斌), LI Guo-donga (李国栋). Mechanical Properties and Residue Stress of Four Kinds of ZrC Coatings Prepared by Chemical Vapor Deposition[J]. Journal of shanghai Jiaotong University (Science), 2012, 17(6): 706-711.

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