On understanding the microstructure of SiC/SiC Ceramic Matrix Composites (CMCs) after a material removal process

MATERIALS SCIENCE AND ENGINEERING A-STRUCTURAL MATERIALS PROPERTIES MICROSTRUCTURE AND PROCESSING

卷:743

Article

Diaz, O. Gavalda¹  Axinte, D. A.¹  Butler-Smith, P.¹  Novovic, D.² 

[1] Univ Nottingham, Fac Engn, Rolls Royce Univ Technol Ctr Mfg & On Wing Techno, Nottingham NG8 1BB, England

[2] Rolls Royce Plc, Mfg Technol, London DE24 8ER, England

关键词: Ceramic Matrix Composites;    Microstructure;    Residual stresses;    Material removal mechanism;    Machining;   

DOI  :  10.1016/j.msea.2018.11.037

来源: Elsevier

【 摘 要 】

The unique material nature (e.g. hard, brittle, heterogeneous and orthotropic) of SiC-based Ceramic Matrix Composites (CMCs) highly affects the outcomes of machining process by inducing high thereto-mechanical loads during material removal. This can result in severe material damage which in turn causes a reduction of the in-service life of critical structural ceramic components (such as in aero-engines or nuclear reactors). In this study, the phenomenon by which the material removal mechanism during drilling influences the CMC surface integrity are discussed by characterising the fracture and deformation phenomena on the CMC's constituents - i.e. SiC and Si materials. Moreover, the strain induced to the surface, together with the changes in chemical composition are characterised via micro Raman spectroscopy and related to the principles of residual stresses upon cutting. This results in a novel understanding of the material removal process that governs cutting of SiC-based CMCs while emphasising how the different microstructure, morphology and nature of ceramics behave under the same cutting conditions. This study has therefore led to a comprehension of how the microstructure of complex hierarchical ceramic materials such as SiC/SiC CMCs is affected by a mechanical cutting process and opens avenues to understand the structure damage under other machining operations (e.g. milling, grinding).

【 授权许可】

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