• Journal of the Korean institute of surface engineering
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• v.20 no.2
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• pp.77-85
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• 1987

최근 10년간 공구의 耐마모 코우팅 분야는 급속한 발전을 하여 왔다. 처음에는 초경 합금 인서트를 TiC로 단층 코우팅하였다. 코우팅 효과를 고려함에 따라 TiC, Ti(C,N), TiN으로 코우팅하게 되었고 또한 $Al_2O_3$ 코우팅도 많이 사용하였다. 처음의 코우팅은 공정작업의 어려움으로 극히 어려웠으나, 밀링작업에 대한 코우팅은 발달하여 왔다. 그림1.은 선반가공과 밀링작업을 하기 위한 초경 합금 인서트를 공구지지대로 지지하고 코우팅 한 것이다. 코우팅의 발전은 공구 코우팅과 강의 마모부분에 코우팅 하는 것으로 많이 발전하였다. 현재 CVD방법이 코우팅에 쓰이고 있으며 저온에서 강에 코우팅하는 작업에는 PVD방법을 도입하기에 이르렀고, 공구의 수명은 3~10배 증가하였으며 코우팅의 효과는 아래와 같이 요약된다. 1. 마찰력 감소, 열발생 감소, 절삭력 감소 2. 고속 절삭시 공구의 표면과 칩사이 확산 감소(코우팅은 확산 장벽으로 작용함) 3. 갤링(galling)을 막아줌. 공구의 수명 연장과 여러분야에 사용하기 위한 최적의 요구 조건은 다음과 같다. -공구재와 접촉시 화학적 안정성 -耐 산화성 -耐 마모성 -갤링의 방지 -耐 충격성 耐 열주기 -모재에 대한 코우팅 재의 충분한 접착성.

• Journal of the Korean Society of Manufacturing Process Engineers
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• v.21 no.8
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• pp.1-8
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• 2022

Inconel 718 is nickel-based and is increasingly being used as a key component in the nuclear, aerospace, and chemical industries which require high fatigue strength and oxidation, because of its excellent corrosion resistance, heat resistance, and wear resistance. It is a heat-resistant alloy which has excellent mechanical properties; however, material deformation, cracking, and shaking occur because of the high cutting temperature accumulated on the cutting surface during cutting processing, and heat accumulated at the insert boundary. Owing to these characteristics, various studies have been conducted, such as developing a tool exclusively for non-deletion, analyzing tool wear, and developing a tool cooling system. However, the optimization of the cutting process is still insufficient. In this study, the optimal process conditions were derived experimentally by cutting conditions according to the insert type during the cutting of Inconel 718.

• Journal of the Korean Society of Manufacturing Process Engineers
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• v.20 no.6
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• pp.10-16
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• 2021

Drilling is a crucial process that takes up a significant amount of weight during machining operations. In addition, drill tip-type tools and related operations have been developed for manufacturing industries to achieve economic efficiency. In this study, SM45C carbon steel, widely used for machine structures, was utilized as the working material after quenching and tempering. Insert-tip types of carbide tools, such as TiN and TiAlN, were used as tool materials. Drilling conditions such as the spindle revolution, feed rate, step of cut, and tool diameter were used to measure roughness, roundness, and straightness using the orthogonal array table statistical method. The surface roughness, roundness, and straightness characteristics based on the conditions were analyzed using ANOVA. The results showed that the spindle speed and feed rate were the main factors influencing carbide insert-tip drilling under the same conditions as the experimental conditions.

• Journal of Power System Engineering
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• v.12 no.3
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• pp.66-71
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• 2008

Diamond-like-carbon (DLC) coatings could be good candidates as solid lubricants for cutting tools in dry machining of aluminum alloy. In this work, DLC thin films were produced as a friction reduction coating for WC-Co insert tip using the plasma immersion ion beam deposition (PIIED) technique. DLC coatings were also coated on $Al_2O_3$ specimens and high temperature wear tested up to $400^{\circ}C$ in dry air to observe the survivability of the DLC coating in simulated severe cutting conditions using a pin-on-disc tribotester with Hertzian contact stress of 1.3GPa. It showed reduced friction coefficients of minimum 0.02 up to $400^{\circ}C$. And cutting performance of DLC coated WC-Co insert tips to Al 6061 alloy were conducted in a high speed machining center. The main problems of built-up edge formation in aluminum machining are drastically reduced with improved surface roughness. The improvements were mainly related to the low friction coefficient of DLC to Al alloy and the anti-adhesion of Al alloy to WE due to the inertness of DLC.

• Journal of the Korean institute of surface engineering
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• v.41 no.2
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• pp.43-47
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• 2008

Cubic boron nitride(c-BN) films were deposited on tungsten carbide insert tool by microwave plasma enhanced chemical vapor deposition(MPECVD) from a gas mixture of triethyl borate$(B(C_2H_5O)_3)$, ammonia $(NH_3)$, hydrogen$(H_2)$ and argon(Ar). The qualities of deposited thin film were investigated by x-ray diffrac-tion(XRD), field emission scanning electron microscopy(FE-SEM) and micro Raman spectroscope. The surface morphologies of the synthesised BN as well as crystallinity appear to be highly dependent on the flow rate of $B(C_2H_5O)_3$ and $(NH_3)$ gases. The deposited film had more crystallized phases with 5 scem of $B(C_2H_5O)_3$ and $(NH_3)$ gases than with 2 sccm, and the phase was identified as c-BN by micro Raman spectroscope and XRD. The adhesion strength were also increased with increasing flow rates of $B(C_2H_5O)_3$ and $(NH_3)$ gases.

• Journal of the Korean Vacuum Society
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• v.15 no.1
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• pp.110-116
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• 2006

The mechanical property and cutting performance of the cutting tools coated with nanoscale nyktukatered nitride film have been investigated. $Ti_{0.54}Al_{0.46}N-CrN$ and $Ti_{0.84}Al_{0.16}N-NlN$ systems, which showed super-lattice in nanoscale multilayered coating, were deposited on WC-Co insert by UBM sputtering, The superlattice coatings with different bilayer periods were manufactured by controlling deposition parameters. The superlattice formation and hardness of the nanoscale multilayered nitride film and the cutting performance of the insert coated with the film were examined. The hardness and cutting performance were dependent on the bilayer periods of the coatings. The flank wear of the inserts with superlattice coatings were decreased over $20\%$, compared to those of commonly used cutting tools coated with TiAIN single phase.