Journal of Korea Foundry Society最新文献_第8页

The Influence of [Mn/S] Ratios on the Fracture Morphology of a Heavy-section Steel Castings at Elevated Temperature [Mn/S]比对高温大断面铸钢件断口形貌的影响

Journal of Korea Foundry Society Pub Date : 2014-10-31 DOI: 10.7777/JKFS.2014.34.5.170

Sung-Gyoo Kim, Ji-tae Kim, B. Park, Heung-Il Park

{"title":"The Influence of [Mn/S] Ratios on the Fracture Morphology of a Heavy-section Steel Castings at Elevated Temperature","authors":"Sung-Gyoo Kim, Ji-tae Kim, B. Park, Heung-Il Park","doi":"10.7777/JKFS.2014.34.5.170","DOIUrl":"https://doi.org/10.7777/JKFS.2014.34.5.170","url":null,"abstract":"Using the Gleeble test, the effects of [Mn/S] ratios and the presence of sulfides on the high-temperature fracture morphology of heavy-section steel castings were analysed via the observations of the microstructures. The specimens for which the [Mn/S] ratio was in the range of 60~80 showed a ductile fracture morphology with an area reduction of more than 60%, while some specimens with similar [Mn/S] ratios showed a brittle fracture morphology with an area reduction of 0.0% due to the liquidation of sulfides at the grain boundary. The fracture morphology was classified into three types in the Gleeble high-temperature tensile test specimens. The first type showed dimple formation at the grain boundary, the formation of globular MnS sulfides, and plastic deformation of sulfides at an elevated temperature, indicating a needle-point type of ductile fracture with area reductions of 96.0~97.8%. The sec-ond type was a knife-edge type brittle fracture with an area reduction of 0.0% due to the film-type liquidation of sulfides at the grain boundary, band-type liquidation, and the liquidation of a terraced nipple pattern. The third type was the typical ductile fracture with an area reduction of 31.3~81.0%, in accordance with the mixture of dimples with in the grains and terraced nipple pattern at the grain boundary.","PeriodicalId":16318,"journal":{"name":"Journal of Korea Foundry Society","volume":"95 1","pages":"170-178"},"PeriodicalIF":0.0,"publicationDate":"2014-10-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"83404966","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}

引用次数: 0

Al2Ca를 함유한 A356 합금에서의 다양한 열처리 조건에 따른공정 Si 개량화 거동 含有Al2Ca的A356合金，根据不同热处理条件的工艺Si改良化行为

Journal of Korea Foundry Society Pub Date : 2014-10-31 DOI: 10.7777/JKFS.2014.34.5.156

김세준, 현승균, 김세광, 윤영옥

引用次数: 2

Effect of Mold Preheat Temperature on Solidification Crack Strength of AC2B Aluminum Alloy 模具预热温度对AC2B铝合金凝固裂纹强度的影响

Journal of Korea Foundry Society Pub Date : 2014-10-31 DOI: 10.7777/JKFS.2014.34.5.162

Heon-Joo Kim

{"title":"Effect of Mold Preheat Temperature on Solidification Crack Strength of AC2B Aluminum Alloy","authors":"Heon-Joo Kim","doi":"10.7777/JKFS.2014.34.5.162","DOIUrl":"https://doi.org/10.7777/JKFS.2014.34.5.162","url":null,"abstract":"The effect of the mold preheat temperature on the solidification crack strength was investigated in AC2B aluminum alloy. A tension type apparatus as part of a solidification crack test which could measure the stress-strain relationship quantitatively was utilized. The evaluation of the solidification crack strength with varying mold preheat temperatures was performed by the test procedure established in this research. When the mold preheat temperatures were 250C, 150C and 50C, the solidification crack strengths were found to be 7.8 Kgf/cm, 12.9 Kgf/cm and 28.6 Kgf/cm, respectively. In the same way, when the mold preheat temperatures were 250C, 150C and 50C, the corresponding temperatures of the failure sites were 610C, 600C and 571C, and the calculated solid fractions were 14.0%, 29.3% and 50.8% when the specimens failed, respectively. The solidification crack strength increased in proportion to the solid fraction of the failure site. The solidification crack strength obtained in this test is assumed to reflect the effects of metallurgical factors on the thermo-plastic characteristics of a solidifying alloy such as the grain size of the solid, the grain morphology, and the distribution of solid grain.","PeriodicalId":16318,"journal":{"name":"Journal of Korea Foundry Society","volume":"284 1","pages":"162-169"},"PeriodicalIF":0.0,"publicationDate":"2014-10-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"73399123","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}

引用次数: 1

Microstructure and Properties of Mg-RE-Zn Alloys for High Conductivity Parts 高导电性零件用Mg-RE-Zn合金的组织与性能

Journal of Korea Foundry Society Pub Date : 2014-10-31 DOI: 10.7777/JKFS.2014.34.5.151

Jeong-Min Kim, N. Kim

引用次数: 0

Thixo Extrusion and Reheating Characteristics of Semi Solid A356 Alloy 半固态A356合金的触相挤压及再加热特性

Journal of Korea Foundry Society Pub Date : 2014-08-31 DOI: 10.7777/JKFS.2014.34.4.123

Dae-hwan Kim, Hyun-Ju Jung, Sung-Yong Shim, Su-gun Lim, Sang-yong Lee

引用次数: 0

Influence of Cu and Zn Contents on the Properties of Al-Fe-Cu-Mg Based Casting Alloys Cu和Zn含量对Al-Fe-Cu-Mg基铸造合金性能的影响

Journal of Korea Foundry Society Pub Date : 2014-08-31 DOI: 10.7777/JKFS.2014.34.4.130

Jeong-Min Kim, N. Kim, Jesik Shin, K. Kim, Se-Hyun Ko

{"title":"Influence of Cu and Zn Contents on the Properties of Al-Fe-Cu-Mg Based Casting Alloys","authors":"Jeong-Min Kim, N. Kim, Jesik Shin, K. Kim, Se-Hyun Ko","doi":"10.7777/JKFS.2014.34.4.130","DOIUrl":"https://doi.org/10.7777/JKFS.2014.34.4.130","url":null,"abstract":"Abstract Efforts have been made to develop new silicon-free aluminum casting alloys that possess high electrical and thermal con-ductivity. In this research Al-Fe-Cu-Mg alloys with various Cu and Mg contents were investigated for their various properties. Asthe Cu or Mg content was increased, the electrical conductivity gradually decreased, while the tensile strength of the Al-Fe-Cu-Mgalloy tended to be improved. It was found that fluidity was generally inversely proportional to the Cu content, but the alloys con-taining 1%Mg showed considerably low fluidity, regardless of the Cu content. Key words : Aluminum, Casting, Conductivity, Tensile strength, Fluidity 1. 서 론 알루미늄 및 알루미늄합금은 대표적인 경량소재로서 비강도가 높고 전기 및 열 전도도가 우수하므로 자동차, 항공, 전기/전자 산업 등에서 널리 사용되고 있다. 예를 들어, 고출력LED 방열부품소재로서 중요하게 활용되고 있는데, 최근 전기/전자제품의 소형화 및 고집적화가 진행됨에 따라 보다 전도성이 우수한 새로운 알루미늄합금의 출현이 필요한 시점이기도하다. 기존에 주로 사용되는 알루미늄 주조합금은 주조성과 강도가 우수하지만 통상적으로 다량의 Si을 포함하고 있어 전도성이 상대적으로 낮고 주조공정 후 표면처리에 어려움이 있다.상용합금계인 Al-Si계 주조합금은 순수한 알루미늄에 비해 열전도도가 절반 수준까지 낮은 경우가 대부분인 것으로 알려져있으며[1], 따라서 최근 들어 전도성을 현저히 저하시키는 Si을 완전히 배제한 상태에서 양호한 강도와 주조성을 보유한새로운 고전도성 알루미늄합금의 개발연구가 활발하게 진행되고 있다[2,3].방열부품용 알루미늄합금은 보통 높은 강도가 요구되지는 않으나 활용분야에 따라 일정 수준이상의 강도가 필요하므로 새로운 고전도성 합금의 조성에 따른 기계적 성질을 조사할 가치가 있다. 또한 방열부품용 알루미늄합금은 생산성과 경제성이우수한 주조공정으로 대부분 제조되므로 주조특성이 중요하며,특히 주형 충전성을 의미하는 유동도가 낮으면 불량률의 증가와 생산성의 저하가 예상된다. 알루미늄합금에서 Si은 응고 중응고잠열을 다량 방출함으로써 유동도의 증가에 매우 효과적인합금원소이므로 제거할 경우 유동도의 저하가 심각할 수 있어확인이 필요하다. 합금의 유동도는 여러 가지 재료 및 공정변수의 영향을 받는 복잡한 현상으로서 많은 연구에도 불구하고아직도 완전하게 규명되어 있지 못 하다[4-6]. 그럼에도 불구하고 일반적으로 합금의 유동도는 응고구간과 매우 밀접한 관련이 있는 것으로 알려져 있는데, 즉 응고구간이 확대될수록 유동도는 감소하는 일반적인 경향을 보인다[4,7].Received:May. 25, 2014;Revised:Aug. 5, 2014;Accepted:Aug. 18, 2014","PeriodicalId":16318,"journal":{"name":"Journal of Korea Foundry Society","volume":"104 1","pages":"130-135"},"PeriodicalIF":0.0,"publicationDate":"2014-08-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"80640169","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}

引用次数: 0

Quantitative Evaluation of Solidification Crack Strength of AC2B Aluminum Casting Alloy AC2B铝合金铸件凝固裂纹强度的定量评价

Journal of Korea Foundry Society Pub Date : 2014-08-31 DOI: 10.7777/JKFS.2014.34.4.136

Heon-Joo Kim

引用次数: 1

Electrical Conductivity by Addition of Zn and Cu on Mg-Zn-Cu Alloys 添加Zn和Cu在Mg-Zn-Cu合金上的电导率

Journal of Korea Foundry Society Pub Date : 2014-06-30 DOI: 10.7777/JKFS.2014.34.3.100

D. Ye, Hyun Sik Kim, M. Kang, Jung Dae Kim, Haeyoung Jeoung

{"title":"Electrical Conductivity by Addition of Zn and Cu on Mg-Zn-Cu Alloys","authors":"D. Ye, Hyun Sik Kim, M. Kang, Jung Dae Kim, Haeyoung Jeoung","doi":"10.7777/JKFS.2014.34.3.100","DOIUrl":"https://doi.org/10.7777/JKFS.2014.34.3.100","url":null,"abstract":"In recent years, Mg and its alloys have attracted a great deal of attention due to their low density, relatively excellent castability, and straightforward recyclability. Mg alloys have been widely applied to various industrial fields, and are representatively used in automotive and electronic parts. According to previous researches, the electrical conductivity of Mg alloys greatly decreases with increasing Al content. However, with the addition of Zn and/or Cu, the electrical conductivity of Mg alloys is maintained or slightly increased, and improved mechanical properties are obtained as well. On this basis, Mg-Zn-Cu alloys have been investigated in the present study with a focus on the effect of adding Zn and Cu on the electrical conductivity. The Zn and Cu contents ranged from 4 to 6wt.% and 0 to 1.5wt.%, respectively. Ternary Mg-Zn-Cu alloys have been prepared by gravity casting in a steel mold. In the as-casting condition, the electrical conductivity of Mg-Zn-Cu alloys showed a linear increasing trend with decreasing Zn and increasing Cu contents. Furthermore, impact values of Zn = − 1.5 and Cu = 2.5 were determined for these alloys by electrical conductivity tests.","PeriodicalId":16318,"journal":{"name":"Journal of Korea Foundry Society","volume":"35 1","pages":"100-106"},"PeriodicalIF":0.0,"publicationDate":"2014-06-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"75083841","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}

引用次数: 2

Thixo-extrusion of Semi Solid 7075 Aluminum Alloys and Mechanical Properties of The Extrudates 半固态7075铝合金的触点挤压及挤压物的力学性能

Journal of Korea Foundry Society Pub Date : 2014-06-30 DOI: 10.7777/JKFS.2014.34.3.087

Tae-young Choi, Dae-hwan Kim, Soo-Bae Kim, Sung-Young Shim, Su-gun Lim

引用次数: 2

Estimation of Permeability of Green Sand Mould by Performing Sensitivity Analysis on Neural Networks Model 基于神经网络模型敏感性分析的绿砂型渗透率估算

Journal of Korea Foundry Society Pub Date : 2014-06-30 DOI: 10.7777/JKFS.2014.34.3.107

N. Reddy, Yong-Hyun Baek, Seong-Gyeong Kim, B. Hur

引用次数: 7