• Title/Summary/Keyword: Abrasive waterjet machining

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Nozzle Condition Monitoring System for Abrasive Waterjet Process (연마재 워터젯을 위한 노즐상태 모니터링 시스템 설계)

  • Kim, Jeong-Uk;Kim, Roh-Won;Kim, Chul-Min;Kim, Sung-Ryul;Kim, Hyun-Hee;Lee, Kyung-Chang
    • Journal of the Korean Society of Industry Convergence
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    • v.23 no.5
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    • pp.817-823
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    • 2020
  • In recent, the machining of difficult-to-cut materials such as titanium alloys, stainless steel, Inconel, ceramic, glass, and carbon fiber reinforced plastics (CFRP) used in aerospace, automobile, medical industry is actively researched. Abrasive waterjet is a non-traditional processing method in which ultra-high pressure water and abrasive particles are mixed in a mixing chamber and shoot out jet through a nozzle, and removed by erosion due to collision with a material. In particular, the nozzle of the abrasive waterjet is one of the most important parts that affect the machining quality as with a cutting tool in general machining. It is very important to monitor the condition of the nozzle because the workpiece is uncut or the surface quality deteriorates due to wear, expanding of the bore, damage of the nozzle and clogging of the abrasive, etc. Therefore, in this paper, we propose a monitoring system based on Acoustic Emission(AE) sensor that can detect nozzle condition in real time during AWJ processing.

Characteristics of Cut Surface by Abrasive Waterjet Cutting of Titanium Alloy (티타늄 합금의 연마제 워터 제트 절단에 의한 절단표면 특성)

  • Chung Nam-Yong;Jin Yun-Ho
    • Journal of Welding and Joining
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    • v.23 no.1
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    • pp.86-93
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    • 2005
  • Abrasive waterjet (AWJ) can provide a more effective means for precision of difficult -to-machining materials such as ceramics and titanium alloys. The present study is focused on the surface roughness of abrasive waterjet cut surfaces. This paper investigated theoretical and experimental surface characteristics associated with abrasive waterjet cutting of titanium alloy Gr2. It is shown that the proper variations of several cutting parameters such as waterjet cutting pressure, cutting speed and cutting depth improve the roughness and characteristics on specimen surfaces produced by AWJ cutting. From the experimental results by AWJ cutting of titanium alloy Gr2, the optimal cutting conditions to improve the surface roughness and precision were proposed and discussed.

Understanding the Material Removal Mechanisms of Abrasive Water Jet Drilling Process by Acoustic Emission Technique

  • Kwak, Hyo-Sung;Kovacevic, Radovan
    • Proceedings of the Korean Society of Machine Tool Engineers Conference
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    • 1998.03a
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    • pp.40-52
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    • 1998
  • Among the non-traditional machining methods, Abrasive waterjet machining process shows big promise in drilling difficult-to-machine materials due to its numerous advantages such as absence of heat affect zone and thermal distortion. Acoustic emission signal technique is used to understand about material removal mechanisms during abrasive waterjet drilling process. More information about the drilling process is derived through frequency decomposition of auto regressive moving average modeling representing acoustic emission signals.

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Cutting Characteristics of Quartz by Abrasive Waterjet (연마제 워터 제트에 의한 쿼츠의 절단특성)

  • Jin, Yun-Ho;Chung, Nam-Yong;Kim, Kyung-Hoon
    • Proceedings of the KSME Conference
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    • 2004.11a
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    • pp.922-927
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    • 2004
  • Abrasive waterjet (AWJ) cutting is an emerging technology for precision cutting of difficult-to-machining materials with the distinct advantages of no thermal effect, high machinability, high flexibility and small cutting forces. This paper investigated theoretical and experimental cutting characteristics associated with abrasive waterjet cutting of quartz GE214. It is shown that the proper variations of several cutting parameters such as waterjet pressure, cutting speed and cutting depth improve the roughness on workpiece surfaces produced by AWJ cutting. From the experimental results by AWJ cutting of quartz GE214, the optimal cutting conditions to improve the surface roughness were proposed and discussed.

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Cutting Characteristics of Quartz by Abrasive Waterjet (연마제 워터 제트에 의한 쿼츠의 절단특성)

  • Chung, Nam-Yong;Jin, Yun-Ho
    • Transactions of the Korean Society of Automotive Engineers
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    • v.13 no.2
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    • pp.118-126
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    • 2005
  • Abrasive waterjet (AWJ) cutting is an emerging technology for precision cutting of difficult-to-machining materials with the distinct advantages of no thermal effect, high machinability, high flexibility and small cutting forces. This paper investigated theoretical and experimental cutting characteristics associated with abrasive waterjet cutting of quartz GE214. It is shown that the proper variations of several cutting parameters such as waterjet cutting pressure, cutting speed and cutting depth improve the roughness on workpiece surfaces produced by AWJ cutting. From the experimental results by AWJ cutting of quartz GE214, the optimal cutting conditions to improve the surface roughness and precision were proposed and discussed.

Molecular Simulation of Nano-Scale Waterjet Machining (나노스케일 워터젯 가공에 대한 분자시뮬레이션 연구)

  • Sang-Hoon Lee;Hyun-Joon Kim;Tae-Wook Kim
    • Tribology and Lubricants
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    • v.39 no.5
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    • pp.216-219
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    • 2023
  • This study employs molecular dynamics simulations to investigate the material behavior of workpieces in waterjet machining processes. To gain fundamental insights into waterjet machining, simulations were conducted using pure water, excluding abrasive particles. The simulation model comprised thousands of water molecules interacting with a single crystal metal workpiece. Water molecule clusters were imparted with various velocities to initiate collisions with the metal workpiece. The material behavior of the metal surface was analyzed with respect to the applied velocity conditions, considering the intricate interplay between water molecules and the workpiece at the atomic scale. The results demonstrated that the machining of the metal workpiece occurred only when water molecules were endowed with velocities above a certain threshold. In cases where energy was insufficient, the metal workpiece exhibited a slight increase in surface roughness due to mild plastic deformation, without undergoing substantial material removal. When machining occurred, the ejection of material revealed a 3-fold symmetric pattern, confirming that material removal in waterjet machining of the metal workpiece is primarily driven by plastic deformation-induced material ejection. This research provides crucial insights into the mechanisms underlying waterjet machining and enhances our understanding of material behavior during the process. The findings can be valuable in optimizing waterjet machining techniques.

Transition Mechanism from Brittle Fracture to Ductile Shear when Machining Brittle Materials with an Abrasive Waterjet

  • Huang, Chuanzhen;Zhu, Hongtao;Lu, Xinyu;Li, Quanlai;Che, Cuilian
    • International Journal of Precision Engineering and Manufacturing
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    • v.9 no.2
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    • pp.11-17
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    • 2008
  • Critical erosion kinetic energy models for radial/median cracks and lateral cracks in a workpiece are established in this study. We used experimental results to demonstrate that the fracture erosion resistance and erosion machining number could be used to evaluate the brittle fracture resistance and machinability of a workpiece. Erosion kinetic energy models were developed to predict brittle fracture and ductile shear, and a critical erosion kinetic energy model was developed to predict the transition from brittle fracture to ductile shear. These models were verified experimentally.

Applicability of abrasive waterjet cutting to irradiated graphite decommissioning

  • Francesco Perotti ;Eros Mossini ;Elena Macerata;Massimiliano Annoni ;Michele Monno
    • Nuclear Engineering and Technology
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    • v.55 no.7
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    • pp.2356-2365
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    • 2023
  • Characterization, dismantling and pre-disposal management of irradiated graphite (i-graphite) have an important role in safe decommissioning of several nuclear facilities which used this material as moderator and reflector. In addition to common radiation protection issues, easily volatizing long-lived radionuclides and stored Wigner energy could be released during imprudent retrieval and processing of i-graphite. With this regard, among all cutting technologies, abrasive waterjet (AWJ) can successfully achieve all of the thermo-mechanical and radiation protection objectives. In this work, factorial experiments were designed and systematically conducted to characterize the AWJ processing parameters and the machining capability. Moreover, the limitation of dust production and secondary waste generation has been addressed since they are important aspects for radiation protection and radioactive waste management. The promising results obtained on non-irradiated nuclear graphite blocks demonstrate the applicability of AWJ as a valid technology for optimizing the retrieval, storage, and disposal of such radioactive waste. These activities would benefit from the points of view of safety, management, and costs.

Research for Patent Application Tendency in the Super Fine Machining System Using the Wet Waterjet (습식워터젯을 채용한 초정밀 절삭 가공시스템의 특허동향조사에 관한 연구)

  • Kim, Sung-Min;Ko, Jun-Bin;Park, Hee-Sang
    • Transactions of the Korean Society of Machine Tool Engineers
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    • v.18 no.1
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    • pp.1-12
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    • 2009
  • Presently, the semiconductor industry has the chronic problem. In the semiconductor industry, it has the semiconductor wafer, a package, the optical filter cut by using the saw blade, the mold, a laser etc. The cutting technique has the difficulty due to the rising of the production cost by the wearing of mold, the poor quality problem due to generated heat at the moment of cutting procedure and curve cutting etc. The goal of this time of national research and development project is develop the apparatus for solving the problem that the existing cutting technique has. The technology is so called waterjet abrasive method. This technology will be mainly applied to cut a semiconductor package and a wafer. Two important things to be considered are ripple effect(in other words, the scale of a market) and simplicity of an application.

Surface Smoothing of Blasted Glass Micro-Channels Using Abrasive Waterjet (워터젯을 이용한 블라스팅 유리 마이크로 채널의 표면거칠기 개선)

  • Son, Sung-Gyun;Han, Sol-Yi;Sung, In-Ha;Kim, Wook-Bae
    • Transactions of the Korean Society of Mechanical Engineers B
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    • v.37 no.12
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    • pp.1159-1165
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    • 2013
  • Powder blasting, which is an efficient micromachining method for glass, silicon, and ceramics, has a critical disadvantage in that the surface finish is poor owing to the brittle fracture of materials. Low-pressure waterjet machining can be applied to smoothen the rough surface inside the blasted structure. In this study, the surface roughness and sectional dimension of micro-channels are observed during the repetitive application of a waterjet to blasted micro-channels. The asperities and subsurface cracks created by blasting are removed by waterjet machining. Along with the surface roughness, it is found that the sectional dimension increases and the edges of the finished micro-channel become slightly round. Finally, a microfluidic chip is machined by the blasting-waterjet process and a transparent microfluidic channel is obtained efficiently.