Mechanical properties and quality of diamond films synthesized on Ti{endash}6Al{endash}4V alloy using the microwave plasmas of CH{sub 4}/H{sub 2} and CO/H{sub 2} systems

Journal Article · Thu Jan 01 04:00:00 EST 1998 · Journal of Applied Physics

DOI:https://doi.org/10.1063/1.366673· OSTI ID:565609

Catledge, S A; Vohra, Y K ^[1]

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1. Department of Physics, University of Alabama at Birmingham (UAB), Birmingham, Alabama 35294-1170 (United States)

Microwave plasma-enhanced chemical vapor deposition was used to grow diamond films on Ti{endash}6Al{endash}4V alloy using various gas phase precursors. The results of four types of experiments with different gas mixtures are compared: (1) 2{percent} CH{sub 4} in H{sub 2}; (2) initial saturation of 5{percent} CH{sub 4} in H{sub 2} followed by 2{percent} CH{sub 4} in H{sub 2}; (3) a CO-rich mixture with a CO:H{sub 2} ratio of 8; and (4) a hybrid mixture of 2{percent} CH{sub 4} in H{sub 2} followed by a CO:H{sub 2} ratio of 8. The substrate temperature during deposition with CH{sub 4}/H{sub 2} mixtures was between 715 and 810{degree}C, and was between 550 and 600{degree}C when CO/H{sub 2} mixtures were used. Optical emission spectroscopy was used to monitor the excited gas-phase species in the plasma. The films were characterized by micro-Raman spectroscopy, glancing-angle x-ray diffraction, and nanoindentation. The films grown with the type (1) mixture often exhibited good quality with high hardness (70 GPa) but suffered from poor adhesion to the substrate. The films grown with the type (2) mixture were of slightly lower quality and hardness (58 GPa) but exhibited better adhesion. The films produced from the type (3) mixture were adhered, but exhibited very low growth rates and low hardness (18 GPa). Finally, the films produced from the hybrid type (4) mixture were of poor quality and suffered from poor adhesion to the substrate. The differences in interfacial phases and mechanical properties for each film are discussed and the usefulness of each gas mixture for the diamond growth is evaluated. {copyright} {ital 1998 American Institute of Physics.}

• OSTI ID: 565609
• Journal Information: Journal of Applied Physics, Journal Name: Journal of Applied Physics Journal Issue: 1 Vol. 83; ISSN JAPIAU; ISSN 0021-8979
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
ADHESION
CARBON MONOXIDE
CHEMICAL VAPOR DEPOSITION
DIAMONDS
HARDNESS
HYDROGEN
MECHANICAL PROPERTIES
METHANE
PLASMA
RAMAN SPECTRA
THIN FILMS
X-RAY DIFFRACTION