• Title/Summary/Keyword: Casting/Forging

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A Study on The Burr Formation in Sheet Metal Shearing (박판 전단시의 버 형성에 관한 연구)

  • Shin, Yong-Seung;Kim, Byeong-Hee;Kim, Heon-Young;Oh, Soo-Ik
    • Journal of the Korean Society for Precision Engineering
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    • v.19 no.9
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    • pp.166-171
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    • 2002
  • The objective of this paper is to investigate the effect of clearance and the configuration of die system on burr formation by FEM analysis and experimental tests. Compared with casting, forging and machining, shearing has been known, especially in heavy or mass-production industries, as a very economical and fast way to obtain the desired shape Recently, the shearing process becomes widely used in the small and light electronic component manufacturing industries. When shearing a part of sheet metal, the burr formed on the cutting edge is usually unavoidable. The burr would not only degrade the precision of products but also causes additional cost for the deburring process. In this paper, the influence of shearing parameters such as clearance and configurations of the lower pad (ejector) on burr formation is investigated by using the experimental and numerical approach. From the experimental results, it has been shown that the more narrow clearance gives the smaller burr height and the higher shearing forces. The removal of lower holder also makes the sheared surface integrity and the dimensional accuracy become worse. The FEM results (using DEFORM-2D) show good agreement with the experimental results.

Analysis Mechanism of Roll Forming Manufacturing Process using HIP (Hot Isostatic Press) Process (HIP(열간 등방압) 공정을 이용한 압연 롤 제조 공정의 해석 메커니즘)

  • W. Kim
    • Transactions of Materials Processing
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    • v.32 no.3
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    • pp.114-121
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    • 2023
  • During rolling, rolling mill rolls endure wear when shaping metal billets into a desired form, such as bars, plates, and shapes. Such wear affects the lifespan of the rolls and product quality. Therefore, in addition to rigidity, wear performance is a key factor influencing the performance of rolling mill rolls. Conventional methods such as casting and forging have been used to manufacture rolling mill rolls. However, powder alloying methods are increasingly being adopted to enhance wear resistance. These powder manufacturing methods include atomization, canning to shape the powder, hot isostatic pressing to combine the powder alloy with conventional metals, and various wear performance tests on rolls prepared with powder alloys. In this study, numerical simulations and experimental tests were used to develop and elucidate the wear analysis mechanism of rolling mill rolls. The wear characteristics of the rolls under various rolling conditions were analyzed. In addition, experimental tests (wear and surface analysis tests) and wear theory (Archard wear model) were used to evaluate wear. These tests were performed on two different materials in various powder states to evaluate the different aspects of wear resistance. In particular, this study identifies the factors influencing the wear behavior of rolling mill rolls and proposes an analytical approach based on the actual production of products. The developed wear analysis mechanism can serve the future development of rolls with high wear resistance using new materials. Moreover, it can be applied in the mechanical and wear performance testing of new products.

Scientific Analysis of Bronze Materials of Sanoisa Temple in Chongju(I) (청주(淸州) 사뇌사지(思惱寺地) 청동기(靑銅器)의 과학(科學) 분석(分析)(I))

  • Kang, H.T.;Yu, H.S.;Moon, S.Y.;Kwon, H.N.
    • Conservation Science in Museum
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    • v.2
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    • pp.57-68
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    • 2000
  • This study is a scientific analysis of 12 bronze materials which were excavated from Sanoisa temple in Chongju. Analysis of crystalline shape, size and distribution of the each sample metal suggested that they can be classified as tableware(wrought), vessels for memorial service(casting) and bell bronze, which is the same result as classification based on elemental composition. Most of the tableware are forging wares with composition of 8:2:0 in Cu:Sn:Pb, and vessels for memorial service are casting wares whose composition is 7:1:2 in Cu:Sn:Pb, and bell bronze's composition is Cu:Sn:Pb = 85:10:5/9:1:0. The result clearly shows that composition is closely related with usage and manufacturing method of wares. Trace elements such as Co, Fe and As are the elements with high correlation coefficient with Cu, which means they exist as impurities in Cu, and the content of As showed an increase in the order of tableware, memorial service vessels and bell bronze. In addition, the analysis of lead isotope ratio showed that 3 bronze materials with high lead content were made from the lead coming from Japan and China. The composition of the solder was Cu:Sn:Pb = 83:12:5 where small Pb crystals were distributed evenly.

Optimization for high speed manufacturing of Ti-6Al-4V alloy by a selective laser melting technique (SLM 기술을 이용한 Ti-6Al-4V 합금의 고속 적층 공정 최적화 연구)

  • Lee, Kang Pyo;Kim, Kang Min;Kang, Suk Hyun;Han, Jun Hyun;Jung, Kyung Hwan
    • Journal of the Korean Crystal Growth and Crystal Technology
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    • v.28 no.5
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    • pp.217-221
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    • 2018
  • Selective laser melting (SLM) technique is one of the additive manufacturing processes, in which functional, complex parts can be directly manufactured by selective melting layers of powder. SLM technique has received great attention due to offering a facile part-manufacturing route and utilizing a hard-to-manufacturing material (e.g. Ti6Al4V). The SLM process allows the accurate fabrication of near-net shaped parts and the significant reduction in the consumption of raw materials when compared to the traditional manufacturing processes such as casting and/or forging. In this study, we focus the high-speed additive manufacturing of Ti6Al4V parts in the aspect of manufacturing time, controlling various process parameters.

Lineage of Horse Bridle Kept in Yatsushiro Shrine in Kamishima (가미시마 야츠시로 신사(神島八代神社) 소장 재갈의 계보)

  • Shimizu, Yasuji
    • Korean Journal of Heritage: History & Science
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    • v.49 no.4
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    • pp.156-179
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    • 2016
  • Yatsushiro Shrine on the island of Kamishima located in Ise Bay, Japan, contains many cultural artifacts with ancient mirrors in significant numbers. Also included among the artifacts are horse gags and reins that are clearly of the same lineage as the horse harnesses from the unified Shilla era and Goryeo era in Korean history. Type classification and position establishment were carried out on the horse reins kept in the Yatsushiro shrine, including items such as those mentioned previously. Type A horse harness can be classified into 3 types. Based on this classification scheme, the harness type in the Yatsushiro shrine was found to belong to the most recent period. The blacksmith workshop that made the harness was producing iron wares and bronze wares, and it possessed metal forging and metal casting technologies. Note, however, that it was primarily a workshop where iron wares were made. The parts that were visible from the outside when the harness was attached were made from composite bronze, and the reins and bridle linkage were made from iron. Such integration of bronze ware production techniques and iron ware production techniques was an attempt at enhancing the practicality and embellishments on the harness.

An Examination of the Characteristics and Manufacturing Techniques of Joseon-era Metal Bullets (조선시대 금속제 탄환의 특징과 제작기법 검토)

  • Choi, Bo Bae;Lee, Hye Jin;Kim, Myung Hoon;Jeong, Hyeon Jin
    • Conservation Science in Museum
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    • v.28
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    • pp.65-88
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    • 2022
  • The characteristics and behavior of bullets are important because they are directly related to the firearm performance. However, research related to bullets have been small. In this paper, scientific analysis was conducted to find out the materials and manufacturing process of metal bullets during the Joseon Dynasty, owned by Korea Army Museum, and the types of firearms available were classified and organized according to the bullet diameter. As a result, bullets were classified into iron bullets, lead bullets, and lead-coated iron bullets. Most of the iron bullets and lead bullets were made from casting. Some iron bullets were made from forging. And the lead-coated iron bullet was made by pouring molten lead after putting the iron bullet into the mold. Finally, the bullets could be used for Hand Cannon, Matchlock Musket, Frankish Cannon, Hyeon-ja Cannon, Dae-Wiwon Cannon, Small Cannon, and Hong-Yi Cannon.

Jangdo(Small Ornamental Knives) manufacturing process and restoration research using Odong Inlay application (오동상감(烏銅象嵌)기법을 활용한 장도(粧刀)의 제작기술 및 복원연구)

  • Yun, Yong Hyun;Cho, Nam Chul;Jeong, Yeong Sang;Jang, Chu Nam
    • Korean Journal of Heritage: History & Science
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    • v.49 no.2
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    • pp.172-189
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    • 2016
  • In this research, literature research on the Odong material, mixture ratio, casting method and casting facility was conducted on contemporary documents, such as Cheongong Geamul. Also, a long sword was produced using the Odong inlay technique. The sword reproduction steps were as follows; Odong alloying, silver soldering alloying, Odong plate and Silver plate production, hilt and sheath production, metal frame and decorative elements, such as a Dugup (metal frame), production, Odong inlay assembly and final assembly. For the Odong alloy production, the mixture ratio of the true Odong, which has copper and gold ratio of 20:1, was used. This is traditional ratio for high quality product according to $17^{th}$ century metallurgy instruction manual. The silver soldering alloy was produced with silver and brass(Cu 7 : Zn 3) ratio of 5:1 for inlay purpose and 5:2 ratio for simple welding purpose. The true Odong alloy laminated with silver plate was used to produce hilt and sheath. The alloy went through annealing and forging steps to make it into 0.6 mm thick plate and its backing layer, which is a silver plate, had the matching thickness. After the two plates were adhered, the laminated plate went through annealing, forging, engraving, silver inlaying, shaping, silver welding, finishing and polishing steps. During the Odong colouring process, its red surface turns black by induced corrosion and different hues can be achieved depending on its quality. To accomplish the silver inlay Odong techniques, a Hanji saturated with thirty day old urine is wrapped around a hilt and sheath material, then it is left at warm room temperature for two to three hours. The Odong's surface will turn black when silver inlay remains unchanged. Various scientific analysis were conducted to study composition of recreated Odong panel, silver soldering, silver plate and the colouring agent on Odong's surface. The recreated Odong had average out at Cu 95.57 wt% Au 4.16wt% and Cu 98.04 wt% Au 1.95wt%, when documented ratio in the old record is Cu 95wt% and Au 5wt%. The recreated Odong was prone to surface breakage during manufacturing process unlike material made with composition ratio written in the old record. On the silver plate of the silver and Odong laminate, 100wt% Ag was detected and between the two layers Cu, Ag and Au were detected. This proves that the adhesion between the two layers was successfully achieved. The silver soldering had varied composition of Ag depending on the location. This shows uneven composition of the silver welding. A large quantities of S, that was not initially present, was detected on the surface of the black Odong. This indicates that presence of S has influence on Odong colour. Additional study on the chromaticity, additional chemical compounds and its restoration are needed for the further understanding of the origin of Odong colour. The result of Odong alloy testing and recreation, Odong silver inlay long sword production, scientific analysis of the Odong black colouring agent will form an important foundation of knowledge for conservation of Odong artifact.

A Study of Material and Production Technique of Scroll Painting Ring in Joseon (조선시대 족자 장황에 사용된 고리의 재료 및 제작기법 연구)

  • Jang, Yeonhee;Yun, Eunyoung;Kwon, Yoonmi;Kim, Sooyeon
    • Conservation Science in Museum
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    • v.16
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    • pp.56-81
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    • 2015
  • Ring in the scroll painting is one of the mounting elements which are fixed string and tassel to hang, these differ widely in shape and produce a variety of metals. Most traditional shapes of ring have been lost, because of remount, there are used Japanese style rings in present.Therefore, this study examines to shape, production technique and analyze component traditional style rings of 19 traditional scroll paintings in National Museum of Korea for restoration of original style. Ring has been recorded official names; Wonhwan(Ring), Gukhwadong(Chrysanthemum shaped ornaments), Baemok(Ring-shaped nail) in Uigwe. Result of an optical microscope (Leica, M205A), Wonhwan has two type of production technique; one is cutting and bending a metal rod and other is cast. Baemok is made to forging process after metal rod or plate by casting alloy. Baemok decoration is metal plate cutting shape, and then decorates it with pattern by using kicking line engraving, chasing and so on. Component analysis result from portable X-ray fluorescence found various metals, such as, brass, iron silver-cooper. Brass based on copper and zinc used rings of 17 scroll painting. Baemok of Yun Sidal portrait is used iron and plated with a tin-lead alloy. Yi Seogu portrait is silver-cooper alloy in whole ring.

Manufacturing Technique and Conservation of Bigyeokjincheolloe Bomb Shells Excavated from the Ancient Local Government Office and Fortress of Mujang-hyeon, Gochang (고창 무장현 관아와 읍성 출토 비격진천뢰의 제작기법과 보존처리)

  • Kim, Haesol;Huh, Ilkwon
    • Conservation Science in Museum
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    • v.24
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    • pp.17-36
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    • 2020
  • This paper describes the consevation treatment of eleven bigyeokjincheolloe bomb shells that were excavated from the Joseon-period local government office and fortress of Mujang-hyeon (present-day Mujang-myeon) in Gochang in 2018. It also provides information on the production method of the shells revealed through CT scanning, gamma-ray transmission imaging, and metallographic analysis. In preparation for the special exhibition "Bigyeokjincheolloe" at the Jinju National Museum in 2019 (July 16 to August 25), contaminants were removed from the shells and their surface was reinforced during the first phase of conservation treatment. Furthermore, the closures for the shells were identified for the first time. Regarding the production of the shells, the CT scanning and gamma-ray transmission imaging identified many blowholes in the interior of the body and the use of a chaplet on the side of one shell. The side of the body proved to be relatively thinner than the top and bottom. The traces of a hole for pouring molten metal into the center of the bottom indicates that molten metal was indeed emptied into the inverted body. In the metallographic analysis of two of the bodies and one lid, cementite and pearlite structures were identified on the body, indicating that it was made by casting. The presence of the ferrite structure with a partial distribution of the pearlite along with non-metallic inclusion in the lid suggested that the lid was made by forging.