Time-modulated CVD on 0.8 μm-WC-10%-Co hardmetals:: study on diamond nucleation and coating adhesion

被引:8
作者
Ali, N [1 ]
Cabral, G
Lopes, AB
Gracio, J
机构
[1] Univ Aveiro, Ctr Mech Technol & Automat, P-3810193 Aveiro, Portugal
[2] Univ Aveiro, Dept Ceram & Glass Engn, P-3810193 Aveiro, Portugal
关键词
WC-Co hardmetal; chemical vapour deposition (CVD); diamond nucleation;
D O I
10.1016/j.diamond.2003.12.001
中图分类号
T [工业技术];
学科分类号
08 ;
摘要
In this study, we investigate the deposition of diamond films onto 0.8 mum-WC-10%-Co hardmetals using chemical vapour deposition (CVD). Polycrystalline diamond films were deposited using (i) constant methane (CH4) flow, at 3 and 4.5 sccmn, and (ii) modulated CH4 flow at 4.5 sccm and 3 sccm for 8 min and 10 min, respectively. Constant flow of CH4 into the vacuum chamber, during diamond CVD is the conventional approach to deposit diamond films onto a range of materials. The timed CH, modulations are an integral part of our recently proposed process, called time-modulated CVD (TMCVD). The TNICVD process increased drastically the number of diamond crystallites nucleating onto WC-Co. Furthermore, the time-modulated films exhibited (i) smooth surface profile, (ii) improved film coverage and (iii) better coating adhesion. The adhesion was characterised using conventional indentation tests. Data obtained from the micro-Raman spectroscopy technique was used to calculate the biaxial stresses. It is expected that the TMCVD process increases both the diamond nucleation processes and the coating adhesion possibly due to the secondary nucleation processes occurring during the high CH, bursts. It is highly likely that the mechanical interlock at the coating/substrate interface increases during the CH4 pulse cycles. (C) 2003 Elsevier B.V. All rights reserved.
引用
收藏
页码:495 / 502
页数:8
相关论文
共 31 条
[1]   QUANTITATIVE MEASUREMENT OF RESIDUAL BIAXIAL STRESS BY RAMAN-SPECTROSCOPY IN DIAMOND GROWN ON A TI ALLOY BY CHEMICAL-VAPOR-DEPOSITION [J].
AGER, JW ;
DRORY, MD .
PHYSICAL REVIEW B, 1993, 48 (04) :2601-2607
[2]   Quality and reliability in diamond deposition using CVD [J].
Ali, N ;
Ahmed, W ;
Fan, QH .
SURFACE ENGINEERING, 2000, 16 (05) :421-426
[3]   Chromium interlayers as a tool for enhancing diamond adhesion on copper [J].
Ali, N ;
Ahmed, W ;
Rego, CA ;
Fan, QH .
DIAMOND AND RELATED MATERIALS, 2000, 9 (08) :1464-1470
[4]  
Ali N, 1998, MATER WORLD, V6, P348
[5]   Promoting secondary nucleation using methane modulations during diamond chemical vapor deposition to produce smoother, harder, and betterquality films [J].
Ali, N ;
Neto, VF ;
Gracio, J .
JOURNAL OF MATERIALS RESEARCH, 2003, 18 (02) :296-304
[6]  
Ali N., 1998, Surface Engineering, V14, P292
[7]  
ASHFOLD MN, 1994, CHEM SOC REV, P23
[8]   Effects of substrate pretreatment and methane fraction on the optical transparency of nanocrystalline diamond thin films [J].
Bhusari, DM ;
Yang, JR ;
Wang, TY ;
Chen, KH ;
Lin, ST ;
Chen, LC .
JOURNAL OF MATERIALS RESEARCH, 1998, 13 (07) :1769-1773
[9]  
Brookes K.J.A., 1996, WORLD DIRECTORY HDB
[10]   GROWTH OF DIAMOND FILMS ON STAINLESS-STEEL [J].
CHEN, H ;
NIELSEN, ML ;
GOLD, CJ ;
DILLON, RO ;
DIGREGORIO, J ;
FURTAK, T .
THIN SOLID FILMS, 1992, 212 (1-2) :169-172