Journal of the Korean Society for Precision Engineering

Techniques for Tool Life Prediction and Autonomous Tool Change Using Real-time Process Monitoring Data: Seong Hun Ha, Min-Suk Park, Hoon-Hee Lee; J. Korean Soc. Precis. Eng. 2025;42(11):949-958.
Published online November 1, 2025; DOI: https://doi.org/10.7736/JKSPE.025.077

Abstract
PDF

Materials such as titanium alloys, nickel alloys, and stainless steels are difficult to machine due to low thermal conductivity, work hardening, and built-up edge formation, which accelerate tool wear. Frequent tool changes are required, often relying on operator experience, leading to inefficient tool use. While modern machine tools include intelligent tool replacement systems, many legacy machines remain in service, creating a need for practical alternatives. This study proposes a method to autonomously determine tool replacement timing by monitoring machining process signals in real time, enabling automatic tool changes even on conventional machines. Tool wear is evaluated using current and vibration sensors, with the replacement threshold estimated from the maximum current observed in an initial user-defined interval. When real-time signals exceed this threshold, the system updates controller variables to trigger tool changes. Results show vibration data are more sensitive to wear, whereas current data provide greater stability. These findings indicate that a hybrid strategy combining both sensors can enhance accuracy and reliability of tool change decisions, improving machining efficiency for difficult-to-cut materials.

81 View
4 Download

Micro Hole Machining Characteristics of Glassy Carbon Using Electrical Discharge Machining (EDM): Jae Yeon Kim, Ji Hyo Lee, Bo Hyun Kim; J. Korean Soc. Precis. Eng. 2025;42(4):325-332.
Published online April 1, 2025; DOI: https://doi.org/10.7736/JKSPE.025.006

Abstract
PDF

Glassy carbon (GC) has superior properties such as high corrosion resistance, heat resistance, and low adhesion to glass materials in a glass molding process (GMP). In addition, the demand for GC molds is increasing in various industries that require high precision of glass parts. However, GC is a difficult-to-machine material with high hardness and brittleness. Electrical discharge machining (EDM) can machine GC regardless of its strength or hardness. In this study, tungsten carbide (WC-Co) electrode was fabricated by wire electrical discharge grinding (WEDG). Characteristics of EDM of micro holes on GC were then analyzed. As capacitance and voltage increased, material removal rate (MRR) increased while machining time tended to decrease. However, at low voltages, short circuit and secondary discharge occurred, which increased the electrode wear rate (EWR). As a result, a D-shaped electrode that could prevent short circuit and debris accumulation was fabricated and a micro hole array was machined.

Citations

Citations to this article as recorded by

Experimental Study on the Formation of Discharge Crater Morphology in Micro EDM
Jae Yeon Kim, Ui Seok Lee, Hee Jin Kong, Bo Hyun Kim
Journal of the Korean Society for Precision Engineering.2026; 43(1): 61. CrossRef

67 View
6 Download
Crossref

Development of a Regression-Based Tool Life Prediction Model in Manufacturing Environments: Hyun Chul Kim; J. Korean Soc. Precis. Eng. 2025;42(3):247-252.
Published online March 1, 2025; DOI: https://doi.org/10.7736/JKSPE.024.131

Abstract
PDF

This study aimed to develop a regression-based model for predicting tool life in manufacturing environments, with goals of enhancing productivity and reducing costs. In machining operations, particularly roughing processes, high cutting forces can accelerate tool wear, often leading to process interruptions and increased defect rates. Previous research on tool life prediction has frequently relied on empirical models and statistical methods, which face limitations in reliability across diverse machining conditions. To address this issue, we proposed a data-driven approach that could collects tool wear data under varying machining conditions (such as cutting speed, feed rate, and depth of cut) and applied regression models to predict tool life effectively. The model’s performance was validated under multiple conditions to assess its predictive accuracy. This study offers a practical tool life management solution for manufacturing settings, optimizing tool usage and enhancing operational efficiency.

69 View
5 Download

Measurement and Analysis of Air Quality Improvement Effects of Applying Water Methods at Various Train Velocities Using a Twin-disk Rig: HyunWook Lee; J. Korean Soc. Precis. Eng. 2024;41(10):753-758.
Published online October 1, 2024; DOI: https://doi.org/10.7736/JKSPE.024.077

Abstract
PDF

This study investigated the effectiveness of tap water application in reducing nano-sized wear particles at a wheel-rail contact interface and its impact on air quality at different train velocities. Airborne wear particles (AWPs) were simulated using a twin-disk rig at 500, 800, and 1,300 RPM. Mass concentration of nano-sized wear particles was measured using a fast mobility particle sizer (FMPS) at a sampling frequency of 1 Hz. To simulate various vehicle dynamics and contact conditions, the slip rate was incrementally increased from 0 to 3%. During wet conditions, water was applied at a rate of 7 L/min. PM0.1 and PM0.56 under dry and wet conditions were compared to evaluate the method’s effectiveness. The analysis showed that the tap water application method improved the air quality by reducing PM0.56 by at least 74% and PM0.1 by approximately 80%. In conclusion, the water application method can effectively improve air quality by reducing generation of nano-sized wear particles. The train velocity affected the generation of nano-sized wear particles under both conditions.

43 View
0 Download

Fretting Wear Simulation of Press-fit Axles Using an Energy Based Wear Model: Dong Hyung Lee, Young-Sam Ham, Chan Woo Lee; J. Korean Soc. Precis. Eng. 2024;41(9):699-705.
Published online September 1, 2024; DOI: https://doi.org/10.7736/JKSPE.024.071

Abstract
PDF

Railway axles are among critical components ensuring safe and efficient train operations. They are particularly susceptible to damage mechanisms such as fretting wear and fatigue. Fretting induced by high contact pressure and microslip between contact surface can significantly deteriorate fatigue strength at the contact edge of the press-fit section. Recent research has been conducted to enhance axle strength and reliability. However, fretting wear or microcrack formation at the wheel-press-fit zone of axles is still an active area of investigation. Accurately analyzing fretting wear is challenging due to its sensitivity to numerous factors such as changes in friction coefficient, influence of wear particles, and selection of an appropriate wear model. This paper aimed to establish a comprehensive analysis method for fretting wear in interference-fitted axles using finite element analysis (FEA) and numerical analysis techniques. Two wear models were applied in simulations: an Archard wear model and an energy-based wear model. Analysis results were compared with experimental data from rotating bending fatigue press-fit specimens. This comparison will help validate the proposed analysis method and assess the effectiveness and accuracy of different wear models in predicting fretting wear in press-fit axles.

51 View
2 Download

Study on the Effectiveness of Applying Tap Water Method in Reducing Generation of Nano-sized Wear Particles from the Railway Wheel-rail Contact: Air Quality Analysis: HyunWook Lee, YuJin Lee; J. Korean Soc. Precis. Eng. 2024;41(9):681-686.
Published online September 1, 2024; DOI: https://doi.org/10.7736/JKSPE.024.058

Abstract
PDF

The effectiveness of applying tap water method to reduce the generation of nano-sized wear particles from wheel-rail contacts in the aspect of air quality was investigated. A twin-disk rig was utilized to simulate the generation of airborne wear particles resulting from wheel-rail contacts. Slip rates ranging from 0 to 3% were continuously generated to simulate various railway vehicle dynamics. Dry and tap water application conditions (7 L/min) were tested. The mass concentration of wear particles with sizes below 560 nm generated during tests was measured using a Fast Mobility Particle Sizer (FMPS). Particles measured in the slip zone (0 to 3%) were categorized into PM0.02, PM0.03, PM0.1, and PM0.56 for analysis. Results indicated a significant decrease in mass concentration of particles with sizes above 30 nm, while those with sizes below 30 nm showed an increase. Particle reduction rate was -217.2% for PM0.02, -58.5% for PM0.03, 84.5% for PM0.1, and 90.3% for PM0.56. It should be noted that a negative reduction rate indicates an increase in the amount of particle generation. This study demonstrates that the application of tap water is effective in improving air quality by reducing the generation of nano-sized wear particles overall.

Citations

Citations to this article as recorded by

Measurement and Analysis of Air Quality Improvement Effects of Applying Water Methods at Various Train Velocities Using a Twin-disk Rig
HyunWook Lee
Journal of the Korean Society for Precision Engineering.2024; 41(10): 753. CrossRef

61 View
1 Download
Crossref

Study on of Friction and Degradation Characteristics of TPV Glass Run Channel: Su-Bin Cha, Junho Bae, Koo-Hyun Chung; J. Korean Soc. Precis. Eng. 2023;40(11):891-897.
Published online November 1, 2023; DOI: https://doi.org/10.7736/JKSPE.023.078

Abstract
PDF

Recently, the demand for electric vehicles is intensively increasing in accordance with environmental issues in automotive industries. Given that noise level from the electric vehicles is significantly lower than that from conventional vehicles with internal combustion engine, noise management has become more critical. Conventionally, glass run channel (GRC) is used to block the noise and contaminants from outside of vehicle. In this work, the friction and degradation characteristics of GRC with thermoplastic vulcanizate substrate were assessed. The tests were performed using the reciprocating tribo-tester developed to replicate the contact sliding between GRC and window glass. Also, the test conditions were determined in consideration of operating condition of GRC. As a result, the plastic deformation of the lips due to creep and wear of the slip coating deposited on the lip surface were found to be major degradation mechanisms. Furthermore, it was shown that the friction and degradation increased significantly due to the misalignment between GRC and window glass, associated with the significant increase in the reaction force. The results of this work provide fundamental understanding of the degradation characteristics of GRC, and therefore are expected to be useful for the design of GRC with improved performance.

36 View
0 Download

Study on Wear Behavior of 630 Stainless Steel Fabricated by Sequential Metal Additive Manufacturing (Powder Bed Fusion and Directed Energy Deposition): Tae-Geon Kim, Gwang-Yong Shin, Ki-Yong Lee, Do-Sik Shim; J. Korean Soc. Precis. Eng. 2023;40(6):483-492.
Published online June 1, 2023; DOI: https://doi.org/10.7736/JKSPE.022.131

Abstract
PDF

Hybrid additive manufacturing (AM) refers to a combination of two metal AM techniques: material deposition by powder bed fusion (PBF) and additional building by directed energy deposition (DED). This study focused on different characteristics in accordance with relative deposition directions of PBF and DED during hybrid AM production. Characteristics of the sample fabricated by hybrid AM (i.e., hybrid sample) were compared with those of the sample fabricated by PBF or DED. Ferrite was dominant in the microstructure of PBF deposits with very fine retained austenite observed locally. In contrast, lath martensite and retained austenite were formed uniformly in the microstructure of DED deposits. Different microstructures in the two processes were attributed to differences of cooling rate. In DED deposits, microhardness was significantly decreased owing to a high retained austenite fraction. However, in the hybrid sample, microhardness was rapidly increased in the HAZ owing to aging heat treatment for long-term deposition. Principal wear mechanisms of PBF and DED samples were oxidative wear and plastic deformation, respectively.

56 View
2 Download

Tool Wear Monitoring System based on Real-Time Cutting Coefficient Identification: Young Jae Choi, Ki Hyeong Song, Jae Hyeok Kim, and Gu Seon; J. Korean Soc. Precis. Eng. 2022;39(12):891-898.
Published online December 1, 2022; DOI: https://doi.org/10.7736/JKSPE.022.111

Abstract
PDF

Among the monitoring technologies in the metal-cutting process, tool wear is the most critical monitoring factor in real machining sites. Extensive studies have been conducted to monitor equipment breakdown in real-time. For example, tool wear prediction studies using cutting force signals and deducting force coefficient values from the cutting process. However, due to many limitations, those wearable monitoring technologies have not been directly adopted in the field. This paper proposes a novel tool wear predictor using the cutting force coefficient with various cutting tools, and its validity evaluates through cutting tests. Tool wear prediction from the cutting force coefficient should conduct in real-time for adoption in real machining sites. Therefore, a real-time calculation algorithm of the cutting force coefficient and a tool wear estimation method proposes, and they compare with actual tool wear in cutting experiments for validation. Validation cutting tests are conducted with carbon steel and titanium, the most commonly used materials in real cutting sites. In future work, validation will be conducted with different materials and cutting tools, considering the application in real machining sites.

Citations

Citations to this article as recorded by

A Review of Intelligent Machining Process in CNC Machine Tool Systems
Joo Sung Yoon, Il-ha Park, Dong Yoon Lee
International Journal of Precision Engineering and Manufacturing.2025; 26(9): 2243. CrossRef

65 View
0 Download
Crossref

EDM Using Wire Electrical Discharge Milling Electrode: Do Kwan Chung; J. Korean Soc. Precis. Eng. 2022;39(1):21-27.
Published online January 1, 2022; DOI: https://doi.org/10.7736/JKSPE.021.107

Abstract
PDF

In this study, a wire electrical discharge milling electrode was developed, and electric discharge machining characteristics were studied by using the electrode. The wire electrical discharge milling electrode is a form, in which the wire is conveyed by using a cylindrical rod with a hemispherical end as a guide, and it also rotates in one direction around the guide axis. If the wire electrical discharge milling electrode is used in electrical discharge machining (EDM), there is no need to consider electrode wear compensation. The EDM characteristics according to capacitance of the RC circuit and the rotational speed of the wire electrical discharge milling electrode were examined. The machining conditions were selected, and a hemispherical shape with good shape accuracy and fine surface finish was fabricated in two stages of roughing and finishing. By applying the wire electrical discharge milling electrode to the electric discharge milling process, straight and curved shapes were successfully machined.

Citations

Citations to this article as recorded by

Experimental study on the wire electrical discharge machining of PCD with different grain sizes
Kechuang Zhang, Laifa Zhu, Zhongwei Chen, Jianyun Shen, Xuefeng Zhao, Xian Wu
Diamond and Related Materials.2025; 155: 112331. CrossRef

58 View
0 Download
Crossref

Comparative Analysis and Monitoring of Tool Wear in Carbon Fiber Reinforced Plastics Drilling: Kyeong Bin Kim, Jang Hoon Seo, Tae-Gon Kim, Martin Byung-Guk Jun, Young Hun Jeong; J. Korean Soc. Precis. Eng. 2020;37(11):813-818.
Published online November 1, 2020; DOI: https://doi.org/10.7736/JKSPE.020.091

Abstract
PDF

Recently, carbon fiber-reinforced plastic (CFRP) has been attracting much attention in various industries because of its beneficial properties such as excellent strength, modulus per unit density, and anti-corrosion properties. However, there are several issues in its application to various fields. Severe tool wear issues in its machining have been noted as one of the most serious problems because it induces various serious machining failures such as delamination and splintering. In this regard, timely tool replacement is essential for reducing the influence of tool wear. In this study, tool wear, especially flank wear, in the CFRP drilling was investigated and monitored. First, the reproducibility of tool wear under the same machining condition was experimentally evaluated. And it is demonstrated that tool wear may remarkably differ even though the same machining condition is applied to the tools. Then, tool wear monitoring based on the feed motor torque was applied to the detection of tool life ending in the CFRP drilling process. Consequently, it was demonstrated that the average and maximum detection error of the tool life end were less than 7 and 14%, respectively.

Citations

Citations to this article as recorded by

Experimental research on multi-structural parameter optimization of rhombic tooth endmill based on DOE in CFRP milling
Xiaochen Zuo, Junxue Ren, Tiejun Song, Tao Zeng, Mengliu Zhang, Hexuan Liu
Journal of Materials Research and Technology.2025; 38: 2892. CrossRef
Laser Drilling of Micro-Hole Array on CFRP Using Nanosecond Pulsed Fiber Laser
Do Kwan Chung
Journal of the Korean Society of Manufacturing Process Engineers.2024; 23(5): 92. CrossRef
Laser EDM Hybrid Micro Machining of CFRP
Do Kwan Chung, Chan Ho Han, Yu Jin Choi, Jun Seo Park
Journal of the Korean Society for Precision Engineering.2023; 40(2): 99. CrossRef
Comparison of TiAlN DLC and PCD Tool Wear in CFRP Drilling
Jong-Hyun Baek, Su-Jin Kim
Journal of the Korean Society of Manufacturing Process Engineers.2022; 21(5): 77. CrossRef

56 View
2 Download
Crossref

Friction and Wear Characteristics of ABS-like Resin for 3D Printing Under Non-Lubricated Condition: Young Sang Jo, Hyun Seop Lee; J. Korean Soc. Precis. Eng. 2019;36(12):1117-1124.
Published online December 1, 2019; DOI: https://doi.org/10.7736/KSPE.2019.36.12.1117

Abstract
PDF

Recently, as the interest in 3D printing technology has increased, many efforts have been initiated to apply 3D printing technology to various industrial fields. The 3D printing technology is also widely applied in medical, electronics, and apparel industries. Many studies on 3D printing have focused on equipment and material development. However, to use 3D printed components, it is necessary to understand friction and wear phenomenon that will occur during relative motion between two bodies. In this study, friction and wear characteristics of ABS (Acrylonitrile butadiene styrene)-like resin printed with the SLA (Stereo Lithography Apparatus) method were studies by using pin-on-disk and ball-on-disk methods. We also compared friction and wear characteristics between ABS-like resin-SUS304 and ABS-like resin-ABS-like resin. As a result, the relative motion between the ABS-like resin and SUS304 showed lower friction coefficient and wear amount than between the ABSlike resins. Markedly high frictional heat was observed because of the friction by the relative motion between the ABS-like resins. Experimental results show that further research on suitable lubricants is required to use 3D printed ABS-like resin parts as mechanical components.

Citations

Citations to this article as recorded by

A Study on the Wear Phenomena of PLA and PETG Materials for 3D Printing in Non-lubricated Condition
Yonsang Cho, Hyunseop Lee
Journal of the Korean Society for Precision Engineering.2024; 41(2): 145. CrossRef
Effect of Frictional Characteristics on Surface Roughness and Glossiness in Polishing of ABS-Like Resin
Jungyu Son, Hyunseop Lee
Journal of the Korean Society for Precision Engineering.2020; 37(11): 797. CrossRef

75 View
0 Download
Crossref

Experimental Analysis on Multilayer Cladding Using AISI-M4/H13 Metal Powders for Enhancement of Wear Resistance and Shockproof Characteristics: Yeong Kwan Jo, Jae Hyun Yu, Ho Seung Jeong, Gyung Yoon Beak, Gi Yong Lee, Sang-Hu Park; J. Korean Soc. Precis. Eng. 2019;36(11):1059-1064.
Published online November 1, 2019; DOI: https://doi.org/10.7736/KSPE.2019.36.11.1059

Abstract
PDF

Generally, press molds have thermal and mechanical impact wear during usage. To improve the life of the mold, enhancement of mechanical properties such as abrasion resistance and shockproof capability is required. To solve this, we propose the multi-layered cladding process of functional materials with different mixing ratios. AISI-D2 material, known as cold die steel, was used as base material and AISI-M4 and -H13 powders were used for surface cladding on the base metal for high resistance wear and shockproof capability. Four cases of specimens were prepared to compare mechanical properties after tests. Through this study, a specimen multiple cladded with mixing M4 and H13 powders for middle layer and M4 powder only for top layer showed 80% improvement in shockproof capability. We posit that this method based on multi-layer cladding with a combination of functional metal powders increased mold life.

Citations

Citations to this article as recorded by

Hybrid Mechanical Surface Treatment Technology via UNSM and Burnishing for Realizing High Surface Hardness
Yeong-Wook Gil, Sang-Hu Park
Journal of the Korean Society of Manufacturing Process Engineers.2023; 22(10): 10. CrossRef
A Study on the Method and Application of Shaft Repair using Directed Energy Deposition Process
Yoon Sun Lee, Min Kyu Lee, Ji Hyun Sung, Myeong Pyo Hong, Yong Son, Seouk An, Oe Cheol Jeong, Ho Jin Lee
Journal of the Korean Society of Manufacturing Process Engineers.2021; 20(9): 1. CrossRef
Effect of Post-Heat Treatment on the AISI M4 Layer Deposited by Directed Energy Deposition
Gyeong Yun Baek, Gwang Yong Shin, Ki Yong Lee, Do Sik Shim
Metals.2020; 10(6): 703. CrossRef

79 View
0 Download
Crossref

Improvement of Punch Life and Contact Stamping Quality in Ultra-High Speed Press: Ju-Hwan Kim, Hyun-Pyo Shin; J. Korean Soc. Precis. Eng. 2019;36(10):961-967.
Published online October 1, 2019; DOI: https://doi.org/10.7736/KSPE.2019.36.10.961

Abstract
PDF

In recent years, the manufacture connector terminals of electronic devices require an accuracy of several microns and high productivity, thus the need to develop the ultra-high speed press technology. However, increased impulse and vibration of ultra-high speed press have reduced durability of stamping die and induced serious tool wear. To solve this problem, we investigate the changes of vibrations occurring in the die and press machine under ultra-high speed working condition by using a piezoelectric sensor. Moreover, by analyzing the design parameters such as stroke, stripper movement, and collision velocity of the die, impulse and vibration were decreased, thus improving the punch life by 50% under 2,000 SPM (stroke per minute) condition

36 View
1 Download

Development of Diagnosis Algorithm for Cam Wear of Paper Container Using Machine Learning: Seolha Kim, Jaeho Jang, Baeksuk Chu; J. Korean Soc. Precis. Eng. 2019;36(10):953-959.
Published online October 1, 2019; DOI: https://doi.org/10.7736/KSPE.2019.36.10.953

Abstract
PDF

Recently, improvement of productivity of the paper cup forming machine has being conducted by increasing manufacturing speed. However, rapid manufacturing speed imposes high load on cams and cam followers. It accelerates wear and cracking, and increases paper cup failure. In this study, a failure diagnosis algorithm was suggested using vibration data measured from cam driving parts. Among various paper cup forming processes, a test bed imitating the bottom paper attaching process was manufactured. Accelerometers were installed on the test bed to collect data. To diagnose failure from measured data, the K-NN (K-Nearest Neighbor) classifier was used. To find a decision boundary between normal and abnormal state, learning data were collected from normal and abnormal state, and normal and abnormal cams. A few representative features such as mean and variance were selected and transformed to the relevant form for the classifier. Classification experiments were performed with the developed classifier and data gathered from the test bed. According to assigned K values, a successful classification result was obtained which means appropriate failure recognition.

Citations

Citations to this article as recorded by

A Study on 3D Printing Conditions Prediction Model of Bone Plates Using Machine Learning
Song Yeon Lee, Yong Jeong Huh
Journal of the Korean Society for Precision Engineering.2022; 39(4): 291. CrossRef