Authors: Arjun Dey Anoop K Mukhopadhyay S Gangadharan Mithilesh K Sinha Debabrata Basu
Publish Date: 2009/09/10
Volume: 18, Issue: 4, Pages: 578-592
Abstract
Microplasma sprayed MIPS HAP coatings on SS316L substrates were characterized by xray diffraction Fourier transformed infrared spectroscopy optical microscopy scanning electron microscopy SEM field emission scanning electron microscopy FESEM atomic force microscopy and image analysis The coating showed a high degree of crystallinity ~92 a high porosity level of 20 vol and a moderate bonding strength of about 13 MPa The displacement controlled threepoint bend tests and associated results of optical microscopy indicated that crack deflection crack branching and also local crack bridging occurred during crack propagation in the coating The nanohardness H and Young’s modulus E of the MIPSHAP coatings as measured by nanoindentation technique were about 6 and 92 GPa respectively The fracture toughness K ic of the coating was ~06 MPa·m05 From the nanoscratch experiments the critical normal load at which localized microcracking led to delamination was measured to be ~400 mNThe authors are grateful to Director Central Glass and Ceramic Research Institute CGCRI Kolkata for his kind permission to publish this paper and to Dr D K Bhattacharya Head Analytical Facility Division of CGCRI for his kind encouragement during the course of this work One of the authors AD also sincerely acknowledges the support and encouragements received from Prof N R Bandyopadhyay of the School of Materials Science and Engineering Bengal Engineering and Science University BESU Shibpur In addition the authors appreciate the infrastructural support received from all colleagues and particularly those received from the colleagues of the Mechanical Test Section and Bio Ceramics and Coating Division at CGCRI Finally the authors gratefully acknowledge financial support received from DSTSERC Project No GAP 0216 and CSIR Network Project TAREMAC No NWP 0027
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