Ceramic Cutting Tools, State of the Art and Development Trends

Brandt, G.

doi:10.1080/10667857.1999.11752806

Cited by 48 publications

(23 citation statements)

References 16 publications

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“…By comparing the hardness of the material analysed in the present work with most traditional cutting tool materials (Table 1), we notice that the material Al 2 O 3 -NbC 2 , which is prepared with a larger carbon content (48 wt%), presents a hardness superior than that of the pure alumina, as well as that of material ( 17-18 WC-Co [3] 17-20 Al 2 O 3 -30 wt% NbC 1 ) 1 7 Al 2 O 3 -30 wt% NbC 2 ) 1 9 Al 2 O 3 -TiC [5,6] 19-21 Si 3 N 4 [16] 19 Al 2 O 3 [2] 17-18 1 ) This work, polymer (13.2 wt% C).…”

Section: Resultsmentioning

confidence: 93%

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Study of the Surface Composition on Alumina-NbC Composites

Silva

Acchar

Costa

et al. 2001

phys. stat. sol. (a)

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The aim of this work is to analyse an alumina-NbC based composite ceramic made from a polymeric precursor (polysiloxane), alumina and metallic niobium. The materials have a fixed concentration of 60 wt% of polymer and 40% of a mixture of niobium and alumina. These materials are mixed and sintered at 1450 C for 6 h. Alumina based composites have been proposed as excellent materials for use as cutting tools, so knowledge of the superficial composition is extremely important because it is directly related to the hardness and abrasion resistance. Analysis of the surface composition was carried out by electron spectroscopy. It should be emphasized that there may be a meaningful difference between the surface and the interior composition due to a eventual processes such as element segregation to the surface and/or diffusion of elements from the surface to the sample bulk. The analysis was performed by XPS and Auger for three niobium concentrations 10, 20 and 40 wt%, and the results show the appearance of niobium on the surface only at the Nb composition of 10 wt%; this appears to be due to a process of niobium atom migration to the interior of the sample or one involving niobium bonds. For the 10 wt% sample after sintering, the formation of NbC on the surface and the presence of niobium Auger peaks were observed. However, for concentrations larger than 10 wt%, oxides and sub-oxides (NbO, NbO 2 , etc.) were formed which may result in the absence of niobium peaks in the spectra. The analysis of the ratio of niobium to carbon atoms at the surface shows a value of 0.1 which reveals that the quantity of niobium and carbon is not sufficient for ideal formation of niobium carbide (NbC). Under these conditions it is verified that there is only a slight formation of niobium carbide on the surface, which is harmful to the hardness of the material. The excess niobium tends to diffuse towards the interior of the sample and react with the oxygen forming sub-oxides.

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Section: Resultsmentioning

confidence: 93%

“…Alumina based ceramic composites have been developed as alternative materials for metal working [1][2][3][4][5]. Hardness has been improved by the dispersion of hard particles, such as WC [1], TiC [2,[5][6], TiN [7][8], Cr 3 C 2 and NbC [10,11].…”

Section: Introductionmentioning

confidence: 99%

Study of the Surface Composition on Alumina-NbC Composites

Silva

Acchar

Costa

et al. 2001

phys. stat. sol. (a)

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“…The incorporation of theses reinforcing elements may also increase the wear behavior of alumina matrix 5 . Although the cutting tools market is still dominated by WC-Co, alumina-based composite materials may be a good alternative to improve cutting speed and lower production cost 6 . Adding these reinforcing elements increases strength and hardness values at room temperatures in comparison with monolithic material 7 .…”

Section: Introductionmentioning

confidence: 99%

Mechanical performance of alumina reinforced with NbC, TiC and WC

et al. 2012

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The incorporation of refractory hard particles in Al 2 O 3 -based composites may inhibit grain growth of the matrix, which could significantly contribute to mechanical performance of the composite. The present study aimed to investigate the potential use of NbC as alumina reinforcing material, as an alternative to other carbides such as TiC and WC. Alumina was mixed with a fixed carbide concentration of 30 wt.(%) in a ball mill and uniaxially hot-pressed at 1650 °C under a load of 30 MPa in an inert atmosphere. X-ray diffraction revealed no oxidation products were present after the sintering process. Microstructure analyses indicate a homogeneous carbide distribution in the alumina matrix. Results obtained in this study show that alumina reinforced with NbC is a composite material with properties comparable to those of alumina reinforced with WC and TiC, thereby making it good reinforcing material.

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“…Update, WC-Co material is still the most used material for cutting tool applications 4 . The addition of hard refractory particles such as TiC, WC, NbC or mixed carbides causes a pinning effect, reducing the grain growth of alumina, which improves the mechanical performance of this composite materials [5][6][7] .…”

Section: Introductionmentioning

confidence: 99%

Surface characterization of alumina reinforced with niobium carbide obtained by polymer precursor

Acchar

Silva

2006

Mat. Res.

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Active filler controlled pyrolysis of polymers (AFCOP) is a recent method for obtaining near-net shaped ceramic bodies. Alumina based composites have been developed for use as cutting tools, so knowledge of the surface composition is extremely important because it is directly related to the hardness and wear resistance Samples containing a fixed concentration of 60 wt. (%) of polysiloxane and a mixture of metallic niobium and alumina powder were homogenized, uniaxially warm pressed at 80 °C and subsequently pyrolyzed in flowing argon at 1200, 1400 and 1500 °C. Analysis of the surface composition was carried out by X ray photoelectron spectroscopy, infrared spectroscopy, X ray diffraction and scanning electron microscopy. The results have indicated that the formation of the phases on the surface depends strongly on the niobium/carbon ratio in the raw materials.

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Ceramic Cutting Tools, State of the Art and Development Trends

Cited by 48 publications

References 16 publications

Study of the Surface Composition on Alumina-NbC Composites

Study of the Surface Composition on Alumina-NbC Composites

Mechanical performance of alumina reinforced with NbC, TiC and WC

Surface characterization of alumina reinforced with niobium carbide obtained by polymer precursor

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