• Title/Summary/Keyword: 입방정질화붕소 공구

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Machining Characteristics of Ni-based Heat Resisting Alloy (니켈기 초내열합금의 절삭성에 관한 연구)

  • 강신호;김대은
    • 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.

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고경도 금형강의 고속절삭 가공시 CBN공구의 인선형태 변화에 따른 공구수명 평가에 관한 연구

  • 문상돈;오성훈;김태영
    • Proceedings of the Korean Society of Precision Engineering Conference
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    • 1997.04a
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    • pp.927-931
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    • 1997
  • In process of the finish face milling of the hardended STD11 steel(H /sab r/ c50,55) by CBN tool, the optimum tool shape is suggested,which can minimize the tool fracture and by chipping by impact. The obtained results are as follows. (1) The optimal chamfer angel was about 25 .deg. , and the suitable chamfer width was 0.2mm. (2) The nose radius of tool was most excellent at 1.2mm in the viewpoint of tool wear and surface roughness. (3) Wear speed was effected by sintering method of CBN tool B.U.E

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A Study on the Performance of CBN Tools in the Machining of Hardened Die-Materials by High-Speed face Milling (금형용 고경도재의 고속정면밀링 가공시 CBN 공구의 성능에 관한 연구)

  • 조성실;임근영;김태영
    • Proceedings of the Korean Society of Precision Engineering Conference
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    • 1996.11a
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    • pp.26-30
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    • 1996
  • This paper presents the performance of CBN tools in the machining of hardened die-materials, SKD11 and SKD61 steel with HRC 50, by high-speed face milling. Generally, grinding or EDM is being used in machining of hardened materials but the cost is very high. If those can be replaced by cutting, it will be a greatly economical advantage. CBN tool has been recognized as an effective tool in turning, but it has not been in milling. So wear and surface roughness mode of CBN tool for hardened SKD11 and SKD61 steel were investigated by high-speed face milling in this study Also the relation between cutting force and wear mode of CBN tools was investigated.

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Experimental investigation on the wear mechanism of CBN cutting tools (CBM공구의 마모에 관한 실험적 연구)

  • Kwon, O-chul;Lee, Jong-chan
    • Journal of the Korean Society for Precision Engineering
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    • v.11 no.6
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    • pp.86-97
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    • 1994
  • An experimental investigation is reported on the wear mechanism of CBN cutting tools. The cutting experiments were conducted on a lathe equipped with a tool dynamometer for cutting force measurement. The investigation of wear mechanism was executed by observing the worn tools using tool microscope and scanning electron microscope. Results indicate that the flank wear occurs dominantly by abrasive wear mode and the crater wear by adhesive wear mode. The results also indicate that the width of flank wear is closely related with the passive component of cutting force.

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A Study on the Cutting Characteristics of Glass Fiber Reinforced Plastics by Tool Materials and Type (유리섬유강화 플라스틱의 공구재질 및 형상에 따른 절삭특성에 관한 연구)

  • An, Sang-Ook;Noh, Sang-Lai
    • Transactions of the Korean Society of Mechanical Engineers A
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    • v.20 no.4
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    • pp.1216-1224
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    • 1996
  • In the use of glass fiber reinforced plastics it is often necessary to cutting the components, but the cutting GFRP is often made difficult by the delamination of composites and the short tool life. In this paper, the machinability of GFRP by mean of tool materials and type was experimentally investigated. By proper selection of cutting tool material and type excellent machining of this workpiece is achieved. The surface quality relate closely with the feed rate and cutting tools.

Cutting Characteristics of CBN Ball Endmills for STD-11 of Various Hardnesses (STB-11 경도변화에 따른 CBN볼 엔드밀의 절삭특성)

  • 최상우;이기우;이세균;이종찬
    • Proceedings of the Korean Society of Precision Engineering Conference
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    • 1997.04a
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    • pp.1078-1082
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    • 1997
  • The use of CBN tool material has been greatil increased because of the superior metal cutting performance for the machining of hardened steels. This paper presents some experimental results on the ball endmilling of hardened steels. Three different hardnesses of STB-11 workpieces were machined using CBN ball endmills, and the machining charteristics including cutting forces, tool wear, and surface roughness of machined surface were compared. It has been found that the CBN ball endmill works better in the machining of harder workpieces. The microscopic examination explains that this unusual phenomenon is cause by the difference of microstructure of each workpieces.

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A Study on the Optimum Cutting Conditions of CBN Ball Endmill- I (CBN 볼 엔드밀의 최적 절삭조건에 관한 연구- I)

  • 이기우;최상우;이종찬;강추욱
    • Proceedings of the Korean Society of Precision Engineering Conference
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    • 1996.11a
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    • pp.20-25
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    • 1996
  • The needs to machine hardened steels with high productivity and good surface integrity have been increased in the dies & molds industry. This paper presents some experimental results on the CBN ball endmilling for hardened tool steel. This investigation concerns on the effects of cutting speed and cutting fluids on the cutting performance such as cutting forces, tool wear, and surface finish. The wear of CBN ball endmill for each cutting conditions were also examined through the microscopic observation. It has been found out that the higher cutting speeds with cutting fluids result in better cutting performance.

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A Study on the Optimum Cutting Conditions of CBN Ball Endmill (CBN 볼 엔드밀의 최적 절삭조건에 관한 연구)

  • Choi, Sangwoo;Lee, Kiwoo;Lee, Jongchan
    • Journal of the Korean Society for Precision Engineering
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    • v.14 no.10
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    • pp.157-163
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    • 1997
  • The needs to machine hardened steels with high productivity and good sufrace integrity have been increased in the dies & molds industry. This paper presents some experimental results on the CBN ball endmilling for hardened tool steel. This investigation concerns on the effects of cutting fluids, cutting speed, and feed on the cutting performance such as cutting forces, tool wear, and surface finish. The wear of CBN ball endmill for each cutting conditions were also examined through the microscopic observation. It has been found that the higher cutting speeds with cutting fluids result in better cutting performance.

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c-BN 박막의 박리특성 향상에 관한 연구

  • 이성훈;변응선;이건환;이구현;이응직;이상로
    • Proceedings of the Korean Vacuum Society Conference
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    • 2000.02a
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    • pp.124-124
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    • 2000
  • 다이아몬드에 버금가는 높은 경도뿐만 아니라 높은 화학적 안정성 및 열전도성 등 우수한 물리화학적 특성을 가진 입방정 질화붕소(cubic boron nitride)는 마찰.마모, 전자, 광학 등의 여러 분야에서의 산업적 응용이 크게 기대되는 재료이다. 특히 탄화물형성원소에 대해 안정하여 철계금속의 가공을 위한 공구재료로의 응용 또한 크게 기대된다. 이 때문에 각종의 PVD, CVD 공정을 이용하여 c-BN 박막의 합성에 대한 연구가 광범위하게 진행되어 많은 성공사례들이 보고되고 있다. 그러나 c-BN 박막의 유용성에도 불구하고 아직 실제적인 응용이 이루어지지 못한 것은 c-BN 박막의 증착직후 급격한 박리현상 때문이다. 본 연구에서는 평행자기장을 부가한 ME-ARE(Magnetically Enhanced Activated Reactive Evaporation)법을 이용한 c-BN 박막의 합성에서 적용한 증착공정 인자들의 변화에 따른 박리특성 고찰과 함께 다층박막화 및 제 3원소 혼입 방법을 적용하여 박리특성 향상 정도를 조사하였다. BN 박막합성은 전자총에 의해 증발된 보론과 (질소+아르곤) 플라즈마의 활성화반응증착(Activated Reactive Evaporation)에 의해 이루어졌다. 기존의 ARE 장치와 달리 열음극(got cathode)과 양극(anode) 사이에 평행자기장을 부가하여 플라즈마의 증대시켜 반응효율을 높였다. 합성실험용 모재로는 p-type으로 도핑된 (100) Si웨이퍼를 30$\times$40mmzmrl로 절단 후, 10%로 희석된 완충불산용액에 10분간 침적하여 표면의 산화층을 제거한 후 사용하였다. 박막실험실에서의 주요공정변수는 기판바이어스 전압, discharge 전류, Ar/N2가스유량비이었다. 합성된 박막의 결정성 분석을 FTIR을 이용하였으며, BN 박막의상 및 미세구조관찰을 위해 투과전자현미경(TEM;Philips EM400T) 분석을 병행하였고, 박막의 기계적 물성 평가를 위해 미소경도를 측정하였다. 박리특성의 고찰은 대기중에서의 자발적 박리가 일어나 90%이상의 박리가 진행된 시점까지의 시간을 측정하였고, 증착직후 박막의 잔류응력 변화와 연관하여 고찰해 보았다.

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