TY - JOUR
T1 - Solid particle impact of CVD diamond films
AU - Feng, Z.
AU - Tzeng, Y.
AU - Field, J. E.
N1 - Funding Information:
We thank Dr M. M. Chaudhri and Mr Q. Sun for useful discussions, and Mr K. Nishimura of Osaka Diamond Industrial Ltd. for polishing CVD diamond samples. Y.T. would like to thank the Office of Naval Research, SDIO/IST, and the Alabama Microelectronics Center, USA, for partial support of his sabbatical visit to the University of Cambridge.
PY - 1992/5/15
Y1 - 1992/5/15
N2 - Studies of the dynamic impact and static indentation of chemically vapour deposited (CVD) diamond films are described. Polished and unpolished CVD diamond films of thickness ∼ 6 to 15 μm, deposited on both silicon nitride and silicon substrates, were investigated. In the dynamic impact experiments, sand particles with impactvelocities of 34 m s-1 and 59 m s-1 were used. Three stages of impact damage were identified: (i) formation of ring cracks; (ii) partial debonding and penetration of the film; and (iii) full debonding and film removal. The first stage is similar to that occuring with natural diamond. However, the last stage, i.e. the material loss mechanism for CVD films, is mainly caused by delamination of the film. Examination of fracture surfaces using scanning electron microscopy showed that transgranular fracture of the diamond films was quite common despite the polycrystalline nature of the films This suggests that bonding strength between diamond grains strong as that within the grains. Finally, static indentation with a tungsten carbide ball of similar size to the sand particles was performed to determine the fracture strength of polished CVD diamond film and to make a comparison with the impact experiments. The fracture tensile strength for CVD diamond films was found to be ∼2.8 GPa, which is much lower than the reported value of 8.6-12 GPa for natural diamonds.
AB - Studies of the dynamic impact and static indentation of chemically vapour deposited (CVD) diamond films are described. Polished and unpolished CVD diamond films of thickness ∼ 6 to 15 μm, deposited on both silicon nitride and silicon substrates, were investigated. In the dynamic impact experiments, sand particles with impactvelocities of 34 m s-1 and 59 m s-1 were used. Three stages of impact damage were identified: (i) formation of ring cracks; (ii) partial debonding and penetration of the film; and (iii) full debonding and film removal. The first stage is similar to that occuring with natural diamond. However, the last stage, i.e. the material loss mechanism for CVD films, is mainly caused by delamination of the film. Examination of fracture surfaces using scanning electron microscopy showed that transgranular fracture of the diamond films was quite common despite the polycrystalline nature of the films This suggests that bonding strength between diamond grains strong as that within the grains. Finally, static indentation with a tungsten carbide ball of similar size to the sand particles was performed to determine the fracture strength of polished CVD diamond film and to make a comparison with the impact experiments. The fracture tensile strength for CVD diamond films was found to be ∼2.8 GPa, which is much lower than the reported value of 8.6-12 GPa for natural diamonds.
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U2 - 10.1016/0040-6090(92)90497-Y
DO - 10.1016/0040-6090(92)90497-Y
M3 - Article
AN - SCOPUS:0026867654
SN - 0040-6090
VL - 212
SP - 35
EP - 42
JO - Thin Solid Films
JF - Thin Solid Films
IS - 1-2
ER -