The linear motion guideway (LM guide) is one of the key parts of precision motion and positioning, and it requires high straightness, form accuracy, stiffness, and surface quality. LM guides are actively used in manufacturing facilities for automobiles, aerospace, optics, semiconductors, robots, displays, and portable communication equipment. At present, most of LM guides are based on rolling contact, using either balls or rollers. Roller LM guides have been in high demand in recent years in various industrial fields that require high rigidity. In this study, the friction characteristics of ball and roller LM guides with the same rail width were compared, and friction behavior was analyzed. An experimental setup consisting of a driving unit, specimen, force sensor, and signal acquisition unit was constructed, and signals were collected under various conditions. Three lubrication conditions were used: no lubrication (dry surface), ISO-VG 32, and 68, and a wide feed-rate range from 1 to 100 mm/s was selected. The experimental results showed that the ball LM guide and the roller LM guide had significantly different friction characteristics, which were analyzed from the aspect of Stribeck curve components. In conclusion, friction behavior differed according to lubrication conditions in the no-payload state of the ball and roller LM guides, and the effect of lubrication conditions on friction behavior was shown.
{"title":"Study on Comparison of Friction Force between Ball- and Roller-LM Guides","authors":"Hyeon-Jeong Ra, Dong-Wook Kim, Jun-Man Lee, Han-Seon Ryu, Jae-Han Joung, Young-Hun Jeon","doi":"10.7736/jkspe.023.047","DOIUrl":"https://doi.org/10.7736/jkspe.023.047","url":null,"abstract":"The linear motion guideway (LM guide) is one of the key parts of precision motion and positioning, and it requires high straightness, form accuracy, stiffness, and surface quality. LM guides are actively used in manufacturing facilities for automobiles, aerospace, optics, semiconductors, robots, displays, and portable communication equipment. At present, most of LM guides are based on rolling contact, using either balls or rollers. Roller LM guides have been in high demand in recent years in various industrial fields that require high rigidity. In this study, the friction characteristics of ball and roller LM guides with the same rail width were compared, and friction behavior was analyzed. An experimental setup consisting of a driving unit, specimen, force sensor, and signal acquisition unit was constructed, and signals were collected under various conditions. Three lubrication conditions were used: no lubrication (dry surface), ISO-VG 32, and 68, and a wide feed-rate range from 1 to 100 mm/s was selected. The experimental results showed that the ball LM guide and the roller LM guide had significantly different friction characteristics, which were analyzed from the aspect of Stribeck curve components. In conclusion, friction behavior differed according to lubrication conditions in the no-payload state of the ball and roller LM guides, and the effect of lubrication conditions on friction behavior was shown.","PeriodicalId":37663,"journal":{"name":"Journal of the Korean Society for Precision Engineering","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2023-11-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"135715456","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Anomaly detection models using big data generated from facilities and equipment have been adopted for predictive maintenance in the manufacturing industry. When facility faults or defects occur, different patterns of abnormal data are shown owing to their component behaviors. By detecting these pattern changes, it is possible to determine whether a facility abnormality occurs. This study evaluated the anomaly detection results from a combined driving system consisting of three driving motors for about six months at a manufacturing site. The learning data with an autoencoder model for about a month at the beginning of vibration data collection and continuous monitoring of anomalies using reconstruction errors showed that a component defect occurred in one driving motor, and the reconstruction error increased progressively about three months earlier than a facility manager found the failure. In addition, the micro-electro-mechanical systems sensor showed high amplitude in the entire frequency domain when high reconstruction errors occurred. However, the integrated electronics piezoelectric sensor showed different patterns as high amplitude in a specific frequency domain. The results of this study will be helpful for detecting facility abnormalities in combined driving systems using vibration sensors.
{"title":"Anomaly Detection in a Combined Driving System based on Unsupervised Learning","authors":"Kichang Park, Yongkwan Lee","doi":"10.7736/jkspe.023.068","DOIUrl":"https://doi.org/10.7736/jkspe.023.068","url":null,"abstract":"Anomaly detection models using big data generated from facilities and equipment have been adopted for predictive maintenance in the manufacturing industry. When facility faults or defects occur, different patterns of abnormal data are shown owing to their component behaviors. By detecting these pattern changes, it is possible to determine whether a facility abnormality occurs. This study evaluated the anomaly detection results from a combined driving system consisting of three driving motors for about six months at a manufacturing site. The learning data with an autoencoder model for about a month at the beginning of vibration data collection and continuous monitoring of anomalies using reconstruction errors showed that a component defect occurred in one driving motor, and the reconstruction error increased progressively about three months earlier than a facility manager found the failure. In addition, the micro-electro-mechanical systems sensor showed high amplitude in the entire frequency domain when high reconstruction errors occurred. However, the integrated electronics piezoelectric sensor showed different patterns as high amplitude in a specific frequency domain. The results of this study will be helpful for detecting facility abnormalities in combined driving systems using vibration sensors.","PeriodicalId":37663,"journal":{"name":"Journal of the Korean Society for Precision Engineering","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2023-11-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"135715458","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Yongchan Park, Davin Jeong, Hyeontaek Kim, Hyeongmin Kim, Soonwook Hong
In this study, we successfully demonstrated a fuel cell fabrication method using a platinum-samarium-doped ceria (Pt-SDC) composite cathode, which could reduce the platinum content while maintaining the same thickness as the functional layer. The Pt-SDC composite cathode was deposited by a sputtering process in which two materials were simultaneously deposited by a co-sputtering system. Despite the decreased platinum content in the composite cathode, we achieved high performance of the fuel cell since Pt-SCD was able to form triple-phase boundaries (TPBs) not only at the interface between the cathode and the electrolyte but at the entire volumetric surface of the cathode. This composite cathode revealed that Pt-SDC could enhance the oxygen reduction reaction rate by enlarging the TPB site in the cathode. The fuel cell fabricated in this study with a composite cathode demonstrated improved performance at 1.66 times the peak power density of a pristine fuel cell.
{"title":"Fabrication of Platinum-Samarium Doped Ceria Composite Cathode Using Sputtering Technique","authors":"Yongchan Park, Davin Jeong, Hyeontaek Kim, Hyeongmin Kim, Soonwook Hong","doi":"10.7736/jkspe.023.049","DOIUrl":"https://doi.org/10.7736/jkspe.023.049","url":null,"abstract":"In this study, we successfully demonstrated a fuel cell fabrication method using a platinum-samarium-doped ceria (Pt-SDC) composite cathode, which could reduce the platinum content while maintaining the same thickness as the functional layer. The Pt-SDC composite cathode was deposited by a sputtering process in which two materials were simultaneously deposited by a co-sputtering system. Despite the decreased platinum content in the composite cathode, we achieved high performance of the fuel cell since Pt-SCD was able to form triple-phase boundaries (TPBs) not only at the interface between the cathode and the electrolyte but at the entire volumetric surface of the cathode. This composite cathode revealed that Pt-SDC could enhance the oxygen reduction reaction rate by enlarging the TPB site in the cathode. The fuel cell fabricated in this study with a composite cathode demonstrated improved performance at 1.66 times the peak power density of a pristine fuel cell.","PeriodicalId":37663,"journal":{"name":"Journal of the Korean Society for Precision Engineering","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2023-11-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"135715452","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Dong-Jun Lee, Jung-Min Kim, Chul-Soo Jeong, Sangrok Jin
This paper proposes a new rotary welding torch with a ball-jointed mechanical seal structure that simultaneously realizes the enclosure of CO₂ gas, the energization of welding current, and the insulation for system protection. In order to effectively compare the operation mechanism of the proposed device with the conventional rotary welding torch, a schematic technique is introduced to clearly visualize the operation and connection structure of the model. The kinematic state and constraint degrees of freedom of the tool are clearly shown, and it is easy to distinguish between the two designs that use different component parts and connection structures but result in the same final motion. In addition, the four dynamic characteristics of a rotary torch operating at 20 Hz (driving torque, vibration reaction force, natural frequency, and inertial mismatch) were analyzed to demonstrate superior performance to conventional products. The welding test showed that the tool normally operated even in a harsh welding environment, verifying its applicability in the field.
{"title":"Design and Dynamic Characteristics Analysis of Rotating Welding Torch with Ball Joint Type Mechanical Seal structure","authors":"Dong-Jun Lee, Jung-Min Kim, Chul-Soo Jeong, Sangrok Jin","doi":"10.7736/jkspe.023.063","DOIUrl":"https://doi.org/10.7736/jkspe.023.063","url":null,"abstract":"This paper proposes a new rotary welding torch with a ball-jointed mechanical seal structure that simultaneously realizes the enclosure of CO₂ gas, the energization of welding current, and the insulation for system protection. In order to effectively compare the operation mechanism of the proposed device with the conventional rotary welding torch, a schematic technique is introduced to clearly visualize the operation and connection structure of the model. The kinematic state and constraint degrees of freedom of the tool are clearly shown, and it is easy to distinguish between the two designs that use different component parts and connection structures but result in the same final motion. In addition, the four dynamic characteristics of a rotary torch operating at 20 Hz (driving torque, vibration reaction force, natural frequency, and inertial mismatch) were analyzed to demonstrate superior performance to conventional products. The welding test showed that the tool normally operated even in a harsh welding environment, verifying its applicability in the field.","PeriodicalId":37663,"journal":{"name":"Journal of the Korean Society for Precision Engineering","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2023-11-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"135715454","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Recently, with the development of the space, mobility, semiconductor, and precision machinery industries, the processing of precision mechanical parts has been recognized as an important and a high value-added technology. Research on ultra-precision processing is actively underway to produce such products. In addition, eco-friendliness and 0% carbon are emerging as key keywords in modern industrial society, and the need for this is also increasing in the ultra-precision processing field. As the industry advances, environmental issues are becoming a major concern, and in the processing technology field, environmental destruction caused by cutting oil is becoming an issue. To solve this problem, this study measured the movement precision of the global feed system and instaled a Fine Servo that corrects the nm-level movement of the feed system in real time, using a piezoelectric actuator, to finely drive the cutting tool to control the movement necessary for machining. We intended to control variables for ultra-precision machining and measure cutting heat generation in real time to establish a dry cooling method using thermoelectric elements without using cutting oil.
{"title":"Research on Dry Cooling and Processing Precision in Ultra-precision Machining","authors":"Gyung-Il Lee","doi":"10.7736/jkspe.023.112","DOIUrl":"https://doi.org/10.7736/jkspe.023.112","url":null,"abstract":"Recently, with the development of the space, mobility, semiconductor, and precision machinery industries, the processing of precision mechanical parts has been recognized as an important and a high value-added technology. Research on ultra-precision processing is actively underway to produce such products. In addition, eco-friendliness and 0% carbon are emerging as key keywords in modern industrial society, and the need for this is also increasing in the ultra-precision processing field. As the industry advances, environmental issues are becoming a major concern, and in the processing technology field, environmental destruction caused by cutting oil is becoming an issue. To solve this problem, this study measured the movement precision of the global feed system and instaled a Fine Servo that corrects the nm-level movement of the feed system in real time, using a piezoelectric actuator, to finely drive the cutting tool to control the movement necessary for machining. We intended to control variables for ultra-precision machining and measure cutting heat generation in real time to establish a dry cooling method using thermoelectric elements without using cutting oil.","PeriodicalId":37663,"journal":{"name":"Journal of the Korean Society for Precision Engineering","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2023-11-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"135715455","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Hybrid mobile robot is the system that will practically combine legged walking and skated driving in the same system. Therefore, this robot has own problems of inverse kinematics that are not considered in typical walking robots. In this paper, I fully categorized the inverse kinematics problems for hybrid mobile robot with general motion by walking and driving on an inclined plane, including switching end-effectors between foots and blades. I also solved the inverse kinematics for each case of problems. I here actively adopted the coordinate transformation derived from the inclined plane to cope with the random motion of foots and blades on the plane. I then presented several examples of the inverse kinematics problems with specific situations, and verified the validity of the analysis method from the results.
{"title":"Analysis of Inverse Kinematics for Legged Walking and Skated Driving with Hybrid Mobile Robot","authors":"Chang-Soon Hwang, Ho Lee, Bo-Yeong Kang","doi":"10.7736/jkspe.023.067","DOIUrl":"https://doi.org/10.7736/jkspe.023.067","url":null,"abstract":"Hybrid mobile robot is the system that will practically combine legged walking and skated driving in the same system. Therefore, this robot has own problems of inverse kinematics that are not considered in typical walking robots. In this paper, I fully categorized the inverse kinematics problems for hybrid mobile robot with general motion by walking and driving on an inclined plane, including switching end-effectors between foots and blades. I also solved the inverse kinematics for each case of problems. I here actively adopted the coordinate transformation derived from the inclined plane to cope with the random motion of foots and blades on the plane. I then presented several examples of the inverse kinematics problems with specific situations, and verified the validity of the analysis method from the results.","PeriodicalId":37663,"journal":{"name":"Journal of the Korean Society for Precision Engineering","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2023-11-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"135715457","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Study on of Friction and Degradation Characteristics of TPV Glass Run Channel","authors":"Su-Bin Cha, Junho Bae, Koo-Hyun Chung","doi":"10.7736/jkspe.023.078","DOIUrl":"https://doi.org/10.7736/jkspe.023.078","url":null,"abstract":"","PeriodicalId":37663,"journal":{"name":"Journal of the Korean Society for Precision Engineering","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2023-11-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"135715459","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Jung-Soo Kim, Gu Young Cho, Ho-Jun Yoo, Ji-Woong Jeon, Dong-Kun Song, Ye-Rim Kwon, Young-Jo Lee, Seung Hyeok Hong, Su Min Lee, Da Hye Geum
Polymer electrolyte membrane fuel cells (PEMFC) require activation to maximize their performance. Thus, an appropriate activation process is essential for the performance of the fuel cell. In this study, the performance of the fuel cell was investigated by changing the voltage range during the activation process. There were three voltage ranges: 0.3-0.9 V, 0.3-0.6 V, and 0.6-0.9 V. When the fuel cell was activated in the low voltage region, the highest performance was output. On the other hand, it showed the lowest performance at high voltage. The results suggest that it is advantageous to activate the fuel cell with a high current. On the other hand, if activation is performed while outputting at a low current, the generation of water and the electrochemical reaction are insufficient, resulting in a load on the fuel cell. Through this experiment, it was confirmed that the control method greatly affects fuel cell performance when activated.
{"title":"Evaluate the Activation Effect according to the Voltage Range","authors":"Jung-Soo Kim, Gu Young Cho, Ho-Jun Yoo, Ji-Woong Jeon, Dong-Kun Song, Ye-Rim Kwon, Young-Jo Lee, Seung Hyeok Hong, Su Min Lee, Da Hye Geum","doi":"10.7736/jkspe.023.056","DOIUrl":"https://doi.org/10.7736/jkspe.023.056","url":null,"abstract":"Polymer electrolyte membrane fuel cells (PEMFC) require activation to maximize their performance. Thus, an appropriate activation process is essential for the performance of the fuel cell. In this study, the performance of the fuel cell was investigated by changing the voltage range during the activation process. There were three voltage ranges: 0.3-0.9 V, 0.3-0.6 V, and 0.6-0.9 V. When the fuel cell was activated in the low voltage region, the highest performance was output. On the other hand, it showed the lowest performance at high voltage. The results suggest that it is advantageous to activate the fuel cell with a high current. On the other hand, if activation is performed while outputting at a low current, the generation of water and the electrochemical reaction are insufficient, resulting in a load on the fuel cell. Through this experiment, it was confirmed that the control method greatly affects fuel cell performance when activated.","PeriodicalId":37663,"journal":{"name":"Journal of the Korean Society for Precision Engineering","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2023-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"135707681","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Lopez Reyes Rigoberto, Min-Soo Ghim, Young-Sam Cho
Recently, the demand for lightweight open-pore lattice structures with specific stiffness is increasing in many fields, such as the aeronautical, automotive, mechanical and bone tissue engineering sectors. For each concrete application, there is a need to predict its mechanical properties precisely and efficiently. There are several methods used to analyze the mechanical properties of lattice structures. Among them, the asymptotic expansion homogenization method is a more advantageous approach over the experimental, theoretical, and finite element methods, because it handles some of their limitations such as the time-consuming process, size effect, and the high amount of computational resources needed. Therefore, in this work, we use the asymptotic expansion homogenization method to perform a systematic parametric study to calculate the effective stiffness of different open-pore lattice structures. In addition, the designed models were fabricated using an SLA 3D printer, and the effective stiffness of the fabricated specimens was tested via UTM experiment to validate the numerical results computed by the asymptotic expansion homogenization method. Consequently, it was proved that this method is precise and effective for predicting the mechanical properties of lattice structures.
{"title":"A Comparative Analysis of AEH (Asymptotic Expansion Homogenization) Results and Experimental Findings of Various Additive Manufactured Lattice Structures","authors":"Lopez Reyes Rigoberto, Min-Soo Ghim, Young-Sam Cho","doi":"10.7736/jkspe.023.071","DOIUrl":"https://doi.org/10.7736/jkspe.023.071","url":null,"abstract":"Recently, the demand for lightweight open-pore lattice structures with specific stiffness is increasing in many fields, such as the aeronautical, automotive, mechanical and bone tissue engineering sectors. For each concrete application, there is a need to predict its mechanical properties precisely and efficiently. There are several methods used to analyze the mechanical properties of lattice structures. Among them, the asymptotic expansion homogenization method is a more advantageous approach over the experimental, theoretical, and finite element methods, because it handles some of their limitations such as the time-consuming process, size effect, and the high amount of computational resources needed. Therefore, in this work, we use the asymptotic expansion homogenization method to perform a systematic parametric study to calculate the effective stiffness of different open-pore lattice structures. In addition, the designed models were fabricated using an SLA 3D printer, and the effective stiffness of the fabricated specimens was tested via UTM experiment to validate the numerical results computed by the asymptotic expansion homogenization method. Consequently, it was proved that this method is precise and effective for predicting the mechanical properties of lattice structures.","PeriodicalId":37663,"journal":{"name":"Journal of the Korean Society for Precision Engineering","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2023-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"135707686","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
In this study, based on directed energy deposition (DED) technology, one of the additive manufacturing technologies, a porous material fabricated by mixing various aluminum alloys and foaming agent was manufactured. First, the foaming agent formed pores inside the deposited materials and differences in foaming characteristics were observed depending on the type of aluminum. Also, the foaming characteristics according to the laser power, which is a representative process variable, were analyzed. As a result, a closed-cell porous material with a maximum porosity at a laser power of 1,100 W was manufactured. Results of the compression test showed that the porous material made by the pores generated therein collapses to absorb energy, and the internal pores disappear to become high density. Therefore, Young’s modulus and yield stress were reduced by the pores inside the sample of pure aluminum and Al6063. However, it was found that the specific energy absorption, which is an advantage of the foamed materials, increased compared to non-porous materials. The findings of this study confirmed that it was possible to manufacture DED-applied foam materials using aluminum powder and a foaming agent.
{"title":"Study on Fabrication of Closed-cell Aluminum Foam Using Directed Energy Deposition","authors":"Hwa-Jeong Kim, Do-Sik Shim","doi":"10.7736/jkspe.023.076","DOIUrl":"https://doi.org/10.7736/jkspe.023.076","url":null,"abstract":"In this study, based on directed energy deposition (DED) technology, one of the additive manufacturing technologies, a porous material fabricated by mixing various aluminum alloys and foaming agent was manufactured. First, the foaming agent formed pores inside the deposited materials and differences in foaming characteristics were observed depending on the type of aluminum. Also, the foaming characteristics according to the laser power, which is a representative process variable, were analyzed. As a result, a closed-cell porous material with a maximum porosity at a laser power of 1,100 W was manufactured. Results of the compression test showed that the porous material made by the pores generated therein collapses to absorb energy, and the internal pores disappear to become high density. Therefore, Young’s modulus and yield stress were reduced by the pores inside the sample of pure aluminum and Al6063. However, it was found that the specific energy absorption, which is an advantage of the foamed materials, increased compared to non-porous materials. The findings of this study confirmed that it was possible to manufacture DED-applied foam materials using aluminum powder and a foaming agent.","PeriodicalId":37663,"journal":{"name":"Journal of the Korean Society for Precision Engineering","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2023-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"135707680","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
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