• Tribology and Lubricants
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• v.6 no.1
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• pp.82-88
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• 1990

In order to investigate tribological effects of coatings on different places on tool wear, commercial quality coated inserts were tested in production speed machining after the coatings on clearance or rake face of coated tools were selectively removed. The experimental results demonstrated that the primary role of coatings in tool wear was the reduction of the thermochemical adhesion between the tool material and workpiece. And the coating on rake face was observed to retard the progress of flank wear. In case of machining carbon steel, multicoated tools showed the most favorable results for considering the notch wear.

• Journal of the Korean Society for Precision Engineering
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• v.15 no.4
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• pp.27-35
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• 1998

Ni-based heat resisting alloys are commonly used for high temperature applications such as in aircraft engines and gas turbines. In this work, the machinability of Nimonic 263 alloy is investigated with respect to optimum tool type and cutting conditions for both continuous and discontinuous machining as well as weld region. Among the five types of tools tested, K25 tool experienced the least of damage in machining the weld region. Furthermore, despite their superior high temperature hardness, Si-Al-O-N and CBN tools peformed poorly in machining Nimonic 263.

• Journal of the Korean Professional Engineers Association
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• v.21 no.1
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• pp.5-12
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• 1988

The purpose of this paper is to investigate on the optimum coating thickness layer of TiC-Al$_2$O$_3$ coated cemented carbide tool. Chemical Vapor Deposition (CVD) of a thick film of TiC-A1$_2$O$_3$ on a cemented carbide produces an intermediate layer, $1.5mutextrm{m}$, 4.5${\mu}{\textrm}{m}$, 7.5${\mu}{\textrm}{m}$ 10.5${\mu}{\textrm}{m}$, 4 kind of TiC between the substrate and the $1.5mutextrm{m}$ constant thick A1$_2$O$_3$ coating. Experiments were carried out with the test relationship between coating thickness and shear angle, surface roughness, cutting force, microphotograph of crater wear, flank wear, tool life. From the experimental results, it was found that the optimum coating thickness of TiC-A1$_2$O$_3$ is 6${\mu}{\textrm}{m}$. Although the coating thickness layer 9${\mu}{\textrm}{m}$. 12${\mu}{\textrm}{m}$ have a much loger tool wear than an 3${\mu}{\textrm}{m}$, 6${\mu}{\textrm}{m}$ coating tool in cutting condition feed 0.05mm/rev, and the condition of feed 0.2mm/rev, 0.3mm/rev has upon in the shot time phenomenon of chipping.

• Journal of the Korean Society of Manufacturing Process Engineers
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• v.15 no.4
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• pp.40-45
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• 2016

Interrupted cutting has different cutting characteristics compared with continuous cutting. In interrupted cutting, the workpiece has a groove that regularly impacts the cutting tool and workpiece. Therefore, tool damage occurs rapidly, and this increases the cutting force and surface roughness. In this study, we performed interrupted cutting of carbon steel for machine structure (SM45C) using a coated carbide tool (TT7100). To predict the cutting force, we analyzed the experimental results with a regression analysis. The results were as follows: We confirmed that the factors affecting the principal force and radial force were cutting speed, depth of cut, and feed rate. From the multi-regression analysis, we deduced regression equations, and their coefficients of determination were 89.6, 89.27, and 28.27 for the principal, radial, and feed forces, respectively. This means that the regression equations were significant for the principal and radial forces but not for the feed force.

• Journal of the Korean institute of surface engineering
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• v.25 no.1
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• pp.16-23
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• 1992

Generally brittle eta phase produced during TiC deposition has a bad effect on the TRS (transverse rupture strength ; thoughness). Therefore it is necessary to reduce eta(η) phase for the improvement of tool life. At this experiment some properties (TRS, bonding strength, tool life, eta phase) have been investigated by inserting TiN or TiCN underlayer between TiC layer and substrate. The results obtained were as fellows; 1. by inserting underlayer eta phase was decreased and TRS was increased, but the bonding strength was decreased. 2. the diffusion of W, Co from the substrate was hindered by the underlayer. 3. TiC layer with TiCN underlayer had the finsest gain size. 4. by inserting underlayer (TiCN or TiN) the tool life was improved and especially notch and crater wear resistance was greatly improved.

• Journal of the Korean Society of Manufacturing Process Engineers
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• v.13 no.3
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• pp.77-82
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• 2014

In this study, we carried out the interrupted cutting of carbon steel for a machine structure (SM45C) with a CVD-coated tool and conducted an ANOVA test and a confidence interval analysis to find factors influence the surface roughness and to obtain a regression equation. We found that factor which mostly affects the surface roughness during interrupted cutting was the feed rate. The cutting speed and depth of the cut only had small effect on the surface roughness. From the result of a multi-regression analysis during an interrupted cutting experiment, we obtained regression equation. Its coefficient of determination was 0.918, indicating that the regression equation was predictable. Compared to continuous cutting, if the feed rate increases, the surface roughness will also increase during interrupted cutting.