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The comparison of the sintering methods for diamond cutting tools

Bulut B., Tazegul O., Baydogan M., Kayali E. S.

Journal of Achievements in Materials and Manufacturing Engineering

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2016

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Vol. 76, nr 1

30--35

EN

Purpose: Aim of this study is to compare mechanical, physical, microstructural properties of diamond cutting tools (DCTs) made of Co-Ni-Cu-Sn matrix, produced by Spark Plasma Sintering (SPS) and Conventional Sintering (CS) methods. The main reason for this research is choosing the most convenient and economically manufacturing method for diamond cutting tools. Design/methodology/approach: Aim of this study is to compare mechanical, physical, microstructural properties of diamond cutting tools (DCTs) made of Co-Ni-Cu-Sn matrix, produced by Spark Plasma Sintering (SPS) and Conventional Sintering (CS) methods. The main reason for this research is choosing the most convenient and economically manufacturing method for diamond cutting tools. Findings: The results showed that, the density values of the samples which are produced two different sintering methods are similar. However, the mechanical and microstructure properties of the samples which are produced by SPS method are decent. The robust mechanical properties were obtained at SPS method than CS method. Practical implications: Powder metallurgy is the most common method because of forming new diamond grains due to wearing of matrix. In powder metallurgy, Conventional Sintering (CS) and Spark Plasma Sintering (SPS) are used at DCTs production prevalently. SPS is a short and effective way to produce diamond tools but costs are higher and production capacity is lower than conventional sintering method. Originality/value: This paper demonstrates that the sintering methods can effect the cutting performances of the DCTs. The samples which are produced with CS method had elevated cutting performance on-site field tests.

2

Characterization of thermally oxidized titanium based coating

Cetiner D., Paksoy A. H., Tazegul O., Atar E., Cimenoglu H.

Journal of Achievements in Materials and Manufacturing Engineering

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2016

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Vol. 75, nr 2

49--54

EN

Purpose: Aim of the study is to improve the bioactivity of CoCr alloy upon covering the surface with titanium based coating. Design/methodology/approach: CoCr alloy was coated by cold spraying of powder mixture having a composition of 92 wt.%Ti + 8 wt.%Al. Coated samples were thermally oxidized at 600°C for 60 hours. Characterization of the coating was made by X-Ray diffraction analyses, microstructural surveys, cross-section and surface SEM elemental mapping analyses, roughness and hardness measurements. Findings: Results showed that sequential application of cold spray and thermal oxidation processes provided the multi-layered coating consisting of an inner titanium based layer and an outer oxide layer consisted of TiO2 and Al2O3. Thermal oxidation also caused the remarkable increasing in the surface hardness as compared to the as-cold sprayed state. Practical implications: Modifying the surface of CoCr metallic implants for long term success. Originality/value: Producing a multilayer coating on the surface of the CoCr alloy for biomedical application by sequential application of cold spray and thermal oxidation processes is the orginality of the study.

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Copper matrix composite coatings produced by cold spraying process for electrical applications

Tazegul O., Dylmishi V., Cimenoglu H.

Archives of Civil and Mechanical Engineering

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2016

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Vol. 16, no. 3

344--350

EN

Composite coatings were deposited on commercially pure copper substrates by cold spraying of feedstock consisted of copper and Al2Cu powders. The amount of the Al2Cu powder incorporated in the feedstock varied in between 0 and 15 vol.%. Characterisations of the coatings were done by microstructural examinations, hardness and electrical conductivity measurements and wear tests. Composite coatings deposited from the feedstock containing 5 and 10 vol.% Al2Cu powder exhibited better electrical conductivity and superior wear resistance than the monolithic (Al2Cu free) copper coating. Presence of 15 vol.% Al2Cu in the feedstock diminished both the wear resistance and the electrical conductivity of the coating.