• Journal of the Korean Society for Precision Engineering
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• v.17 no.12
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• pp.94-100
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• 2000

This paper presents a methodology for In-Process monitoring of tool wear by using ultrasonic sensor in turning operation. An integrated single ultrasonic transducer operation at a frequency of 10MHz is placed in contact with the insert tip. The change in amount of the reflected energy from the nose and flank of the tool can be related to the level of tool wear and the mechanical integrity of the tool. As the results, the tool wear monitoring system based on the ultrasonic pulse-echo method was proposed, it is useful to determine a tool life and tool change time.

• Transactions of the Korean Society of Machine Tool Engineers
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• v.10 no.3
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• pp.55-60
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• 2001

A technique on the detection of tool wear based on the ultrasonic pulse-echo method in turning process is presented. The change in amount of the reflected energy from nose and flank of the tool can be related to the level of tool wear and mechanical integrity of the tool, that is, there exists an excellent correlation between the ultrasonic measurement and tool wear. As a results, the method is very useful for the prediction of cutting tool life and the determination of tool exchange period.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 1994.10a
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• pp.73-78
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• 1994

Wear and fracture mode of ceramic tool for hardened SKD11 steel was investigated by face milling in this study. The cutting force and Acoustic Emission(AE) signal were utilized to detect the wear and fracture of ceramic tool. The following conclusions were obtained : (1) The wear and fracture modes of ceramic tool are characterized by three types: \circled1wear which has normal wear and notch wear, \circled2 wear caused by scooping on the rake face, \circled3 large fracture caused by thermal crack in the rake face. (2) The wear behaviour of ceramic tool can be detected by the increase of mean cutting force and the variation of the AE RMS voltage. (3) The catastrophic fracture of ceramic tool can be detected by the cutting force(Fz-component). (4) As the hardness of work material increased, Acoustic Emission RMS value and mean cutting force(Fz) increased linearly, but the tool life decreased.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 1994.10a
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• pp.26-31
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• 1994

The analysis of acoustic emission signals generated during machining has been proposed as a technique for studying both the fundamentals of the cutting process and process and as a methodology for detecting tool fracture on line. In this study, AE signals detected during End Milling were applied as the experimental test to sensing tool fracture on the CNC vertical milling machine. Because automatic monitoring of the cutting condition is one of the most important technologies in machining, the in-process detection of cutting tool life including fracture has been investigated by performing experimental test.

• Transactions of the Korean Society of Mechanical Engineers
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• v.18 no.5
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• pp.1096-1105
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• 1994

A hypereutectic Aluminum-Silicon Alloy is widely used in the parts of automobile because of high-resistance and good strength. In this study, the cutting of hypereutectic A1-Si alloy for economical production was investigated by simulation. Tool life and the extraction rate of Si particles is inversely proportional to the depth of cut. When decreasing the depth of cut, the reduction of single crystal diamond tool cost and tool change time is achieved.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2000.06a
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• pp.35-49
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• 2000

Over the past ten years we have wethnessed a revolution in metalcutting in the field of High Speed Machining. As machining speeds continue to increase, particularly spindle RPM, forces created by unbalance in the spindle, cutting tool, and toolholder require close attaention. It has been observed that these forces, if left uncompensated, can results in poor surface finish, loss of tool life, and spindle bearing failure. The sources of this unbalance needs to be identified and elimated in order to create a smooth, vibration free condition and allow the machine tool and its spindle to operate properly.

• Journal of Surface Science and Engineering
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• v.31 no.6
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• pp.317-324
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• 1998

TiN and TiCN films were deposited on the high speed steel by Cathode Arc Ion Plating(CAIP) Process to investigate the tool life extension effect. The experiment variables were bias voltage and deposit time for the TiN coating and reactive gas flow rate ($CH_4:N_2$) under fixing deposit pressure, are current, bias voltage for the TiCN coating respectively. The micro structure and mechanical properties were investigated and compared for among the coating conditions using various methods and machining practice.

• Journal of the Korean Society of Manufacturing Technology Engineers
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• v.25 no.6
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• pp.445-451
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• 2016

The Inconel 718 alloy is a well-known super-heat-resistant alloy and a difficult-to-cut material. Inconel 718 with excellent corrosion and heat resistance is used in harsh environments. However, the heat generated is not released owing to excellent physical properties, making processes (e.g., adhesion and thermal fatigue) difficult. Tool condition monitoring in machining is significant in reducing manufacturing costs. The cutting tool is easily broken and worn because of the material properties of Inconel 718. Therefore, tool management is required to improve tool life and machinability. This study proposes a method of predicting the tool wear with non-contacting sensors (e.g., IR thermometer for measuring the cutting temperature and a microphone for measuring the sound pressure level in machining). The cutting temperature and sound pressure fluctuation according to the tool condition and cutting force are analyzed using experimental data. This experiment verifies the effectiveness of the non-contact measurement signals in tool condition monitoring.

• Proceedings of the Korean Society of Machine Tool Engineers Conference
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• 2001.04a
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• pp.346-351
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• 2001

The technique of high speed machining is widely studied in machining field. Because the high efficiency and accuracy in machining can be obtained in high speed machining. Unfortunately the development of tool for high speed machining is not close behind that of machining tool. So in this study, we made 4 types flat end mill for obtaining data according to tool shape. Especially, we concentrated in helix angle and number of cutting edge. First we confirmed cutting condition by several experiments and measuring cutting force, tool life, tool wear and chip shape according to cutting length. In results, we acquired the fact that 45 degree helix angle and six cutting edge tool is suitable for high speed machining.

• Proceedings of the Korean Society of Machine Tool Engineers Conference
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• 2002.04a
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• pp.32-37
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• 2002

High speed machining is one of most effective technologies to improve productivity. It can give great advantage for manufacture of die and Moulds. However, when the high speed machining of materials, especially in machining of micro groove, a severely thermal demage was generated on workpiece and tool. Generally, the cutting fluid is used to improve penetration, lubrication, and cooling effect. In order to rise the performance of lubrication, it contains extreme pressure agents (Cl, S, P). But the environment of work room go bad by those additive Therefore, the compressed chilly air with Oil mist system was developed to replace the conventional cutting fluid system. This paper carried out the tests to evaluate the machinability by the cutting environment in high speed micro groove machining of NAK80 (HRC40). Compressed chilly air with oil mist was ejected on the contact area between cutting edge and workpiece. The effectiveness of this developed compressed chilly air with oil mist system was evaluated in terms of tool life. The results showed that the tool life of carbide tool coated TiAIN with compressed chilly air mist cooling was much longer than with dry and flood coolant when cutting the material.