Shandong Engineering Research Center for Super Hard Materials

Zoucheng, China

Shandong Engineering Research Center for Super Hard Materials

Zoucheng, China
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Huang Y.,Shandong University | Huang Y.,Shandong Engineering Research Center for Super Hard Materials | Wang Q.,Shandong University | Wang Q.,Shandong Engineering Research Center for Super Hard Materials | And 5 more authors.
Rare Metals | Year: 2012

Diamond-like carbon (DLC) films have excellent mechanical and chemical properties similar to those of crystalline diamond giving them wide applications as protective coatings. So far, a variety of methods are employed to deposit DLC films. In this study, DLC films with different thicknesses were deposited on Si and glass substrates using RF magnetron PECVD method with C 4H 10 as carbon source. The bonding microstructure, surface morphology and tribological properties at different growing stages of the DLC films were tested. Raman spectra were deconvoluted into D peak at about 1370 cm -1 and G peak around 1590 cm -1, indicating typical features of the DLC films. A linear relationship between the film thickness and the deposition time was found, revealing that the required film thickness may be obtained by the appropriate tune of the deposition time. The concentration of sp 3 and sp 2 carbon atoms in the DLC films was measured by XPS spectra. As the films grew, the sp 3 carbon atoms decreased while sp 2 atoms increased. Surface morphology of the DLC films clearly showed that the films were composed of spherical carbon clusters, which tended to congregate as the deposition time increased. The friction coefficient of the films was very low and an increase was also found with the increase of film thickness corresponding to the results of XPS spectra. The scratch test proved that there was good bonding between the DLC films and the substrates. © The Nonferrous Metals Society of China and Springer-Verlag Berlin Heidelberg 2012.


Li H.-S.,Shandong University | Li H.-S.,Shandong Engineering Research Center for Super hard Materials | Li M.-S.,Shandong University | Li M.-S.,Shandong Engineering Research Center for Super hard Materials | And 2 more authors.
Xinxing Tan Cailiao/ New Carbon Materials | Year: 2010

Diamond synthesis experiments were carried out in the Fe-Ni-C system under high temperature and high pressure (HTHP). The real carbon source forming diamond was investigated by characterizing the structure and phase of the catalyst and the metal surrounding the carbon films, by analyzing the phase diagram and by thermodynamic calculations. These show that the catalyst and metal are composed mainly of cementite and the catalysts rapidly become supersaturated by absorbing carbon from the graphite and separate out as cementite (Fe3C or Fe2C:Fe) when diamond begins to form a nucleus. According to the phase diagram, the diamond nucleation and growth are accompanied by the decomposition of the cementite. Thermodynamic calculations indicate that the phase transformation free energy of Fe3C to diamond and γ-Fe is more negative than that of graphite to diamond in the stable diamond growth region. All of these results indicate that the real carbon source for diamond growth in the Fe-Ni-C system under HTHP is cementite, and not graphite.


Liu L.,Shandong University | Liu L.,Shandong Engineering Research Center for Super Hard Materials | Zhang Y.-P.,Shandong University | Zhang Y.-P.,Shandong Engineering Research Center for Super Hard Materials | And 6 more authors.
Gaoya Wuli Xuebao/Chinese Journal of High Pressure Physics | Year: 2010

The growth process of synthetic diamond single crystals under high-pressure and high-temperature (HPHT) was tested with acoustic emission (AE) technique. A real-time AE monitoring system was built by using a PCI-8 acoustic emission instrument and a LMD-800 hinge-type cubic-anvil press. The characteristics and their variations of the AE signals in the growth and non-growth processes of the diamonds were compared. Furthermore, the spectrum analysis of the AE signals was performed. The experimental results indicated that the AE signals corresponding to the diamond growth process exhibit a low frequency feature. Accordingly, AE testing can be used to study the in-situ reaction mechanics of synthetic diamond single crystals under HPHT.


Liu L.,Shandong University | Liu L.,Shandong Engineering Research Center for Super Hard Materials | Zhang Y.-P.,Shandong University | Zhang Y.-P.,Shandong Engineering Research Center for Super Hard Materials | And 4 more authors.
Gaoya Wuli Xuebao/Chinese Journal of High Pressure Physics | Year: 2010

The growth process of synthetic diamond single crystals under high-pressure and high-temperature (HPHT) was tested with acoustic emission technique. Associated with the fracture morphologies of the synthetic mass, the main acoustic emission dynamic parameters corresponding to growth process of diamond single crystals were analyzed. The results indicate that the energy, count, amplitude and rise time of recorded acoustic emission signals can be objective reflection of the dynamic growth process of diamond single crystals under HPHT. The research provides the important experimental basis for studying the in-situ reaction mechanics of synthetic diamond single crystals under HPHT by using acoustic emission testing.

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