Structural-Phase State of the Interphase Boundary at Thermal Diffusion Metallization of Diamond Grains by Cr and Ti

Structural-phase state of the diamond-metallized coating interphase boundary after thermal diffusion metallization of diamond grains by transition metals Cr, Ti were studied. Metallization were conducted under temperature-time mode corresponding to the sintering of cemented carbide matrices with Cu impregnation. The structural-phase state of the metallized coating and diamond-coating interphase boundary was studied by scanning electron microscopy, X-ray phase analysis and Raman spectroscopy. It was found that a thin continuous metal carbide coating chemically bonded to the diamond and consisting of the corresponding metal, their carbides and small amount of graphite phases is formed during thermal diffusion metallization of diamond by Cr and Ti under the conditions specified in the experiment. It was shown that graphite is formed not by a continuous layer, but in the form of local inclusions. This ensures a strong adhesion of the metallized coating to the diamond through the carbides of the corresponding metals. The results can be useful in the development of compositions and technological methods that provide an increased level of diamond retention in the matrices of tools based on cemented carbide powder mixtures.

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Structural-Phase State of the Interphase Boundary at Thermal Diffusion Metallization of Diamond Grains by Fe, Ni and Co

Materials Science Forum ◽

10.4028/www.scientific.net/msf.992.676 ◽

2020 ◽

Vol 992 ◽

pp. 676-682

Author(s):

P.P. Sharin ◽

M.P. Akimova ◽

S.P. Yakovleva

Keyword(s):

Thermal Diffusion ◽

Interphase Boundary ◽

Phase State ◽

Structural Phase ◽

Adhesive Interaction ◽

Experimental Conditions ◽

Structural Phase State ◽

Metallized Coating ◽

Diffusion Metallization ◽

Complex Structural

Structural-phase state of the diamond-metallized coating interphase boundary after thermal diffusion metallization of diamond grains by transition metals Fe, Ni and Co were studied. Metallization were conducted under temperature-time mode corresponding to the sintering of cemented carbide matrices with Cu impregnation. The structural-phase state of the metallized coating and diamond-coating interphase boundary was studied by scanning electron microscopy, X-ray phase analysis and Raman spectroscopy. A metallized coating strongly adhered to the diamond forms during thermal diffusion metallization of diamond by iron. The metallized coating has a complex structural phase composition of iron, a solid solution of carbon in iron and graphite phases. Nickel and cobalt cause intense catalytic graphitization of diamond with the formation of numerous traces of erosion on its surface under the heating conditions specified in the experiment. The observed weak adhesive interaction of these metals with diamond is probably due to the high melting temperatures of the Ni-C and Co-C eutectics, which does not allow the metals to react with diamond under given experimental conditions.

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Features of the Structural-Phase State of the Diamond-Matrix Boundary Zone in Diamond-Containing Composite Materials

Materials Science Forum ◽

10.4028/www.scientific.net/msf.945.756 ◽

2019 ◽

Vol 945 ◽

pp. 756-762

Author(s):

P.P. Sharin ◽

M.P. Akimova ◽

S.P. Yakovleva

Keyword(s):

Phase State ◽

Structural Phase ◽

Cemented Carbide ◽

Specific Productivity ◽

Matrix Composites ◽

Structural Phase State ◽

X Ray ◽

Hybrid Technology ◽

Metallized Coating ◽

Diamond Retention

Preliminary metallization of the diamond component, which promotes the formation of chemical bonds on the diamond-matrix contact during subsequent sintering, is used to increase the strength of diamond retention and the durability of diamond-containing metal matrix composites. There are restrictions on carrying out metallization to create diamond composites with a cemented carbide matrix, since reheating the metallized coating at high sintering temperatures of carbide powders leads to its destruction, diamond graphitization and deterioration of the material properties. The structural-phase state in the diamond-matrix contact zone has been studied and the main factors providing the strength of diamond retention in diamond-cemented carbide composites obtained by hybrid technology that excludes the reheating of the metallized coating have been revealed. It was revealed, that the developed hybrid technology combining the thermal diffusion metallization of diamond and sintering according to the self-dosed impregnation scheme in one cycle ensures the production and preservation of the metallized coating by the methods of scanning electron microscopy, X-ray diffraction and X-ray phase analysis, Raman spectroscopy. Comparative tests have been carried out and it is shown that the specific productivity of experimental samples of a diamond tool (ruling pencils) with a metallized diamond component is on 39% higher than same parameter of pencils without metallization.

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Effect of xenon on the structural phase state of the surface layer of cemented carbide under pulsed electron-beam irradiation

10.1063/1.4932861 ◽

2015 ◽

Author(s):

Vladimir E. Ovcharenko ◽

Yurii F. Ivanov ◽

Alexey A. Mohovikov ◽

Yu Baohai ◽

Xiaolong Cai ◽

...

Keyword(s):

Surface Layer ◽

Electron Beam ◽

Electron Beam Irradiation ◽

Phase State ◽

Structural Phase ◽

Cemented Carbide ◽

Beam Irradiation ◽

Structural Phase State ◽

Pulsed Electron Beam

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Correlation of the diamond/matrix interphase zone structure with tool efficiency obtained by technology combining diamonds metallization with matrix sintering

Voprosy Materialovedeniya ◽

10.22349/1994-6716-2018-94-2-111-123 ◽

2019 ◽

pp. 111-123 ◽

Cited By ~ 1

Author(s):

P. P. Sharin ◽

M. P. Akimova ◽

V. I. Popov

Keyword(s):

Thermal Diffusion ◽

Shielding Effect ◽

Specific Productivity ◽

Grinding Wheel ◽

Zone Structure ◽

Chromium Powder ◽

Carbide Matrix ◽

Diffusion Metallization ◽

Effect Of Copper ◽

Diamond Retention

The paper studies structure and phase characteristics of the interphase zone diamond/matrix in dressers made by thermal diffusion metallization of a diamond combined with matrix sintering based on WC–Co and Cu impregnation. The compact arrangement of chromium powder particles around diamond grains and the shielding effect of copper foil create favorable conditions for thermal diffusion metallization of diamond at matrix sintering. A metallized coating chemically bonded with diamond and consisting of chromium carbide and solid solution of cobalt in chromium phases provides a strong diamond retention in the carbide matrix. It was shown that it is formed on the surface of the diamond under the conditions specified in the experiment and the temperature – time sintering mode. The specific productivity of experimental dresser made by hybrid technology at straightening green silicon carbide grinding wheel equaled 51.50 cm3/mg exceeding that of the control dresser made without metallization of diamonds by sintering with copper impregnation by 44.66%.

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