Pub Date : 2014-06-30DOI: 10.7777/JKFS.2014.34.3.094
Byung-chul Lee, Sung-Gyoo Kim, B. Park, Heung-Il Park, H. Park
A commercially used Zr-based amorphous alloy was recycled and the effects of introducing carbon during recycling on the glass forming ability and mechanical properties of the alloy were investigated. The initial carbon content used in this study was 229ppm. The carbon content was gradually increased as the number of recycling iterations was increased and after the 4 recycling it rapidly increased. As return scrap was recycled, polygonal particles precipitated, and they were identified as ZrC. The amount of the precipitates also increased with recycling. Tg, Tx and ∆T of the base alloy were 615 K, 696 K and 81 Kr respectively and they changed to 634 K, 706 K and 72 K after the 10 recycling. The decrease of the ∆T value indicates deterioration of the glass forming ability. Hardness was not changed during three iterations of recycling but after the 4 recycling it significantly increased. This is ascribed to an increase of amount of the hard particles, namely ZrC.
{"title":"The Effect of Remelting Cycles and Its Carbon Content on the Glass Forming Ability and Mechanical Properties of the Zr-based Amorphous Alloy Return Scrap","authors":"Byung-chul Lee, Sung-Gyoo Kim, B. Park, Heung-Il Park, H. Park","doi":"10.7777/JKFS.2014.34.3.094","DOIUrl":"https://doi.org/10.7777/JKFS.2014.34.3.094","url":null,"abstract":"A commercially used Zr-based amorphous alloy was recycled and the effects of introducing carbon during recycling on the glass forming ability and mechanical properties of the alloy were investigated. The initial carbon content used in this study was 229ppm. The carbon content was gradually increased as the number of recycling iterations was increased and after the 4 recycling it rapidly increased. As return scrap was recycled, polygonal particles precipitated, and they were identified as ZrC. The amount of the precipitates also increased with recycling. Tg, Tx and ∆T of the base alloy were 615 K, 696 K and 81 Kr respectively and they changed to 634 K, 706 K and 72 K after the 10 recycling. The decrease of the ∆T value indicates deterioration of the glass forming ability. Hardness was not changed during three iterations of recycling but after the 4 recycling it significantly increased. This is ascribed to an increase of amount of the hard particles, namely ZrC.","PeriodicalId":16318,"journal":{"name":"Journal of Korea Foundry Society","volume":"47 1","pages":"94-99"},"PeriodicalIF":0.0,"publicationDate":"2014-06-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"85702867","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}
Pub Date : 2014-04-30DOI: 10.7777/JKFS.2014.34.2.054
Dae-hwan Kim, Tae-young Choi, Sung-Young Shim, Su-gun Lim
In this study, the extruded Al-6.3Zn-2.4Mg alloys were selected among the 7000 series aluminum alloys sensitive to hydrogen environment in order to examine the effects of both the aging conditions and the length of hydrogen charging period on the mechanical properties of the alloy. The specimens were aged for 24hours at (under aging (UA)), (peak aging (PA)), and (over aging (OA)), respectively. Charging tests were performed at RT for 12, 24, 36 hours under potentiostatic conditions (-2000 mV vs (Ag/AgCl)) for 12, 24 and 36 hours in 1M and 0.1% solution. The fracture surface was examined by scanning electron microscopy (SEM). X-ray diffraction (XRD) pattern in peak aged sample was obtained before and after hydrogen charging from extruded Al-6.3Zn-2.4Mg alloys. The decreasing rate of tensile strength and elongation is represented in order of over aging in hydrogen charged Al-6.3Zn-2.4Mg alloys has been confirmed by X-ray diffraction studies.
本研究选取对氢环境敏感的7000系铝合金中挤压的Al-6.3Zn-2.4Mg合金，考察时效条件和充氢时间对合金力学性能的影响。分别在(UA)、(峰值时效(PA)和(超时效(OA))下时效24h。在恒电位条件下(-2000 mV vs (Ag/AgCl))，在1M和0.1%溶液中进行12、24和36小时的充电试验。采用扫描电镜(SEM)对断口表面进行了观察。对Al-6.3Zn-2.4Mg合金挤压充氢前后峰时效试样的x射线衍射(XRD)图进行了分析。x射线衍射研究证实了充氢Al-6.3Zn-2.4Mg合金的抗拉强度和伸长率的递减规律，并以过时效的先后顺序表示。
{"title":"A Study on Mechanical Characteristic of Hydrogen Charged Al-6.3Zn-2.4Mg Alloy","authors":"Dae-hwan Kim, Tae-young Choi, Sung-Young Shim, Su-gun Lim","doi":"10.7777/JKFS.2014.34.2.054","DOIUrl":"https://doi.org/10.7777/JKFS.2014.34.2.054","url":null,"abstract":"In this study, the extruded Al-6.3Zn-2.4Mg alloys were selected among the 7000 series aluminum alloys sensitive to hydrogen environment in order to examine the effects of both the aging conditions and the length of hydrogen charging period on the mechanical properties of the alloy. The specimens were aged for 24hours at (under aging (UA)), (peak aging (PA)), and (over aging (OA)), respectively. Charging tests were performed at RT for 12, 24, 36 hours under potentiostatic conditions (-2000 mV vs (Ag/AgCl)) for 12, 24 and 36 hours in 1M and 0.1% solution. The fracture surface was examined by scanning electron microscopy (SEM). X-ray diffraction (XRD) pattern in peak aged sample was obtained before and after hydrogen charging from extruded Al-6.3Zn-2.4Mg alloys. The decreasing rate of tensile strength and elongation is represented in order of over aging in hydrogen charged Al-6.3Zn-2.4Mg alloys has been confirmed by X-ray diffraction studies.","PeriodicalId":16318,"journal":{"name":"Journal of Korea Foundry Society","volume":"49 1","pages":"54-59"},"PeriodicalIF":0.0,"publicationDate":"2014-04-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"83560804","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}
Pub Date : 2014-04-30DOI: 10.7777/JKFS.2014.34.2.060
Byung-chul Lee, Sung-Gyoo Kim, B. Park, Cha-Hurn Bae, Heung-Il Park
A Zr-based amorphous alloy specimen was produced by vacuum die casting process. The salt spray test was carried out using the specimens in the as-cast, and particle blasted state. Using these specimens, the SEM-EDX and XRD analyses, DSC measurement and bending strength test were conducted. After the salt spray test, the specimens were not experienced phase change and thermal characteristics of the alloys were remained unchanged. In the as-cast specimen, corrosion products were not observed. However, in the particle blasted specimen, pitting corrosion occurred and the detected corrosion products were and . Due to the salt spray test, bending strength of the blasted specimens showed about 100 MPa lower strength than the other specimens. The bending fracture surface was vein pattern which was shown typically in the amorphous alloys.
{"title":"The Effect of Blasting Treatment on the Corrosion Characteristics in the Zr-based Amorphous Alloy Die Castings","authors":"Byung-chul Lee, Sung-Gyoo Kim, B. Park, Cha-Hurn Bae, Heung-Il Park","doi":"10.7777/JKFS.2014.34.2.060","DOIUrl":"https://doi.org/10.7777/JKFS.2014.34.2.060","url":null,"abstract":"A Zr-based amorphous alloy specimen was produced by vacuum die casting process. The salt spray test was carried out using the specimens in the as-cast, and particle blasted state. Using these specimens, the SEM-EDX and XRD analyses, DSC measurement and bending strength test were conducted. After the salt spray test, the specimens were not experienced phase change and thermal characteristics of the alloys were remained unchanged. In the as-cast specimen, corrosion products were not observed. However, in the particle blasted specimen, pitting corrosion occurred and the detected corrosion products were and . Due to the salt spray test, bending strength of the blasted specimens showed about 100 MPa lower strength than the other specimens. The bending fracture surface was vein pattern which was shown typically in the amorphous alloys.","PeriodicalId":16318,"journal":{"name":"Journal of Korea Foundry Society","volume":"182 1","pages":"60-66"},"PeriodicalIF":0.0,"publicationDate":"2014-04-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"85562738","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}
Pub Date : 2014-04-30DOI: 10.7777/JKFS.2014.34.2.049
Byung-chul Lee, Heong Park, B. Park, Sung-Gyoo Kim
In commercial Zr-Nb-Cu-Ni-Al amorphous alloys, expensive element, Zr, was substituted to Sn which was cheaper one, and then, glass forming ability, compressive strength and hardness of them were estimated. Even though the Sn was added up to 1.5%, resulting phase was not changed to the crystalline form. It was confirmed by X-ray diffraction and thermal analyses. In the X-ray profiles, there were no peaks for crystalline phases and typical halo pattern for amorphous phase was appeared at the diffraction angle of 35o~45o. Thermal analyses also showed that the Sn modified alloys were corresponded to the amorphous standards where ∆T(= Tx − Tg) and Trg(= Tg/Tm) affecting to the amorphous forming ability were more than 50K and 0.60 respectively. Compressive strengths were 1.77 GPa, 1.63 GPa, 1.65 GPa and 1.77 GPa for 0%Sn, 0.5%Sn, 1.0%Sn and 1.5%Sn respectively. Hardnesses of the Sn modified alloys were decreased from 752 Hv to 702 Hv in 1.0%Sn and recovered to 746 Hv in 1.5%Sn.
在工业Zr- nb - cu - ni - al非晶合金中，用昂贵元素Zr代替便宜元素Sn，对其玻璃化形成能力、抗压强度和硬度进行了评价。当Sn添加量达到1.5%时，产物相仍未转变为结晶形态。经x射线衍射和热分析证实。在衍射角为35o~45o的x射线衍射谱中，无晶相峰，出现典型的非晶相晕状。热分析表明，Sn改性合金符合非晶态标准，∆T(= Tx−Tg)和Trg(= Tg/Tm)对非晶态形成能力的影响分别大于50K和0.60。0%Sn、0.5%Sn、1.0%Sn和1.5%Sn的抗压强度分别为1.77 GPa、1.63 GPa、1.65 GPa和1.77 GPa。当Sn含量为1.0%时，合金硬度从752 Hv下降到702 Hv，当Sn含量为1.5%时，合金硬度恢复到746 Hv。
{"title":"The Effect of Sn on the Glass Formation Ability of the Zr-based Amorphous Alloy","authors":"Byung-chul Lee, Heong Park, B. Park, Sung-Gyoo Kim","doi":"10.7777/JKFS.2014.34.2.049","DOIUrl":"https://doi.org/10.7777/JKFS.2014.34.2.049","url":null,"abstract":"In commercial Zr-Nb-Cu-Ni-Al amorphous alloys, expensive element, Zr, was substituted to Sn which was cheaper one, and then, glass forming ability, compressive strength and hardness of them were estimated. Even though the Sn was added up to 1.5%, resulting phase was not changed to the crystalline form. It was confirmed by X-ray diffraction and thermal analyses. In the X-ray profiles, there were no peaks for crystalline phases and typical halo pattern for amorphous phase was appeared at the diffraction angle of 35o~45o. Thermal analyses also showed that the Sn modified alloys were corresponded to the amorphous standards where ∆T(= Tx − Tg) and Trg(= Tg/Tm) affecting to the amorphous forming ability were more than 50K and 0.60 respectively. Compressive strengths were 1.77 GPa, 1.63 GPa, 1.65 GPa and 1.77 GPa for 0%Sn, 0.5%Sn, 1.0%Sn and 1.5%Sn respectively. Hardnesses of the Sn modified alloys were decreased from 752 Hv to 702 Hv in 1.0%Sn and recovered to 746 Hv in 1.5%Sn.","PeriodicalId":16318,"journal":{"name":"Journal of Korea Foundry Society","volume":"24 1","pages":"49-53"},"PeriodicalIF":0.0,"publicationDate":"2014-04-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"90266098","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}
Pub Date : 2014-02-28DOI: 10.7777/JKFS.2014.34.1.022
Hwang-Seong Chul, S. Kwak
Internal defects, such as shrinkage during casting, cause stress concentrations and initiate cracking. Therefore, it is important to understand the effects of internal defects on the mechanical properties including the impact behavior. This study evaluates the effects of internal casting defects on the impact performance of A356 Al-alloy castings. The internal shrinkage defects in the casting impact specimen are scanned using an industrial Computed Tomography (CT) scanner, and drop impact tests are performed with varing impact velocities on the A356 casting aluminium specimen (10 mm × 10 mm section area) in order to locate the fracture energy under an impact load. The specimens with defects with a diameter less than 0.35 mm exhibit equivalent fracture impact energies of approximately 32 J and those with a 1.7 mm diameter defect reduced the fracture impact energy by 35%.
内部缺陷，如铸造时的收缩，会引起应力集中并引发开裂。因此，了解内部缺陷对包括冲击行为在内的力学性能的影响是非常重要的。研究了铸件内部缺陷对A356铝合金铸件冲击性能的影响。利用工业计算机断层扫描(CT)扫描铸件冲击试样的内部收缩缺陷，并对A356铸造铝试样(10 mm × 10 mm断面面积)进行不同冲击速度的跌落冲击试验，以确定冲击载荷作用下的断裂能。当缺陷直径小于0.35 mm时，试件的等效断裂冲击能约为32 J，当缺陷直径为1.7 mm时，试件的等效断裂冲击能降低35%。
{"title":"Effect of Shrinkage Defect on Fracture Impact Energy of A356 Cast Aluminum Alloy","authors":"Hwang-Seong Chul, S. Kwak","doi":"10.7777/JKFS.2014.34.1.022","DOIUrl":"https://doi.org/10.7777/JKFS.2014.34.1.022","url":null,"abstract":"Internal defects, such as shrinkage during casting, cause stress concentrations and initiate cracking. Therefore, it is important to understand the effects of internal defects on the mechanical properties including the impact behavior. This study evaluates the effects of internal casting defects on the impact performance of A356 Al-alloy castings. The internal shrinkage defects in the casting impact specimen are scanned using an industrial Computed Tomography (CT) scanner, and drop impact tests are performed with varing impact velocities on the A356 casting aluminium specimen (10 mm × 10 mm section area) in order to locate the fracture energy under an impact load. The specimens with defects with a diameter less than 0.35 mm exhibit equivalent fracture impact energies of approximately 32 J and those with a 1.7 mm diameter defect reduced the fracture impact energy by 35%.","PeriodicalId":16318,"journal":{"name":"Journal of Korea Foundry Society","volume":"1 1","pages":"22-26"},"PeriodicalIF":0.0,"publicationDate":"2014-02-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"84214366","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}
Pub Date : 2014-02-28DOI: 10.7777/JKFS.2014.34.1.006
B. Yoo, Jeong-Ho Kim, H. Yoon, S. Ur
Abstract The mechanical properties of low-pressure die cast (LPDC) A356-T6 automotive road wheels are evaluated and correlated withtheir corresponding microstructures. In this study, two types of alloy wheels processed using different LPDC gating system areinvestigated. The yield stress, tensile stress, and elongation values tested at room temperature are correlated with the secondary den-drite arm spacing (SDAS) with respect to the gating system, and are also compared with similar studies. The SDAS and precipitatesare examined using optical microscopy, scanning electron microscopy (SEM) and energy-dispersive spectroscopy. The phase infor-mation is also investigated using X-ray diffraction. Charpy impact tests are also performed from −100 o C to 200 o C, and the fracturesurfaces are examined using SEM. The impact energy is demonstrated to increase with increasing temperatures without exhibitingspecific transition behaviors as in other nonferrous alloys. The fracture toughness is also evaluated using three point bend test withsingle-edged bend specimens. The obtained fracture toughness values are in good agreement with those in similar studies.Key words: Mechanical property, SDAS, Impact test, Fracture toughness, A356-T6 alloy
{"title":"Mechanical Properties of Low-Pressure Die Cast A356-T6 alloys for Automotive Wheels","authors":"B. Yoo, Jeong-Ho Kim, H. Yoon, S. Ur","doi":"10.7777/JKFS.2014.34.1.006","DOIUrl":"https://doi.org/10.7777/JKFS.2014.34.1.006","url":null,"abstract":"Abstract The mechanical properties of low-pressure die cast (LPDC) A356-T6 automotive road wheels are evaluated and correlated withtheir corresponding microstructures. In this study, two types of alloy wheels processed using different LPDC gating system areinvestigated. The yield stress, tensile stress, and elongation values tested at room temperature are correlated with the secondary den-drite arm spacing (SDAS) with respect to the gating system, and are also compared with similar studies. The SDAS and precipitatesare examined using optical microscopy, scanning electron microscopy (SEM) and energy-dispersive spectroscopy. The phase infor-mation is also investigated using X-ray diffraction. Charpy impact tests are also performed from −100 o C to 200 o C, and the fracturesurfaces are examined using SEM. The impact energy is demonstrated to increase with increasing temperatures without exhibitingspecific transition behaviors as in other nonferrous alloys. The fracture toughness is also evaluated using three point bend test withsingle-edged bend specimens. The obtained fracture toughness values are in good agreement with those in similar studies.Key words: Mechanical property, SDAS, Impact test, Fracture toughness, A356-T6 alloy","PeriodicalId":16318,"journal":{"name":"Journal of Korea Foundry Society","volume":"46 1","pages":"6-13"},"PeriodicalIF":0.0,"publicationDate":"2014-02-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"91255930","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}
Pub Date : 2014-02-28DOI: 10.7777/JKFS.2014.34.1.001
Sang-Yun Shin, Do-Hoon Lee, Seo-Eun Kim, B. Ye
The austempering transformation behavior in Fe-0.7wt.%C-2.3wt.%Si-0.3wt.%Mn steel is investigated. Each specimen was aus-tenitized for 60 min at 900 o C, and austempered at 380 o C for different time periods varying from 2 min to 256 min. After the austempering heat treatment, the Stage I and II evolutions are performed using optical metallography, X-ray diffraction and image analyses. Variations in the X-ray diffraction patterns and lattice parameters of the ferrite and austenite demonstrate that the residual austenite decomposes into ferrite and carbide during the Stage II evolution; moreover the amount of ferrite increases during the Stage I evolution. While the amount of austenite increases during Stage I, it dicreases during Stage II. Overall, the variations in the volume fractions of the microstructure and carbide formation in stages I and II meet high temperature austempering reaction of the ausferrite microstructure.
{"title":"The Austempering Transformation Behavior of Fe-0.7wt.%C-2.3wt.%Si-0.3wt.%Mn Steel","authors":"Sang-Yun Shin, Do-Hoon Lee, Seo-Eun Kim, B. Ye","doi":"10.7777/JKFS.2014.34.1.001","DOIUrl":"https://doi.org/10.7777/JKFS.2014.34.1.001","url":null,"abstract":"The austempering transformation behavior in Fe-0.7wt.%C-2.3wt.%Si-0.3wt.%Mn steel is investigated. Each specimen was aus-tenitized for 60 min at 900 o C, and austempered at 380 o C for different time periods varying from 2 min to 256 min. After the austempering heat treatment, the Stage I and II evolutions are performed using optical metallography, X-ray diffraction and image analyses. Variations in the X-ray diffraction patterns and lattice parameters of the ferrite and austenite demonstrate that the residual austenite decomposes into ferrite and carbide during the Stage II evolution; moreover the amount of ferrite increases during the Stage I evolution. While the amount of austenite increases during Stage I, it dicreases during Stage II. Overall, the variations in the volume fractions of the microstructure and carbide formation in stages I and II meet high temperature austempering reaction of the ausferrite microstructure.","PeriodicalId":16318,"journal":{"name":"Journal of Korea Foundry Society","volume":"11 1","pages":"1-5"},"PeriodicalIF":0.0,"publicationDate":"2014-02-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"82476244","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}
Pub Date : 2014-02-28DOI: 10.7777/JKFS.2014.34.1.014
Hyun Sik Kim, D. Ye, M. Kang, K. Sohn, Hae-Yong Jeong
Magnesium and its alloys are being applied to various kinds of industrial fields, especially their use on automotive parts and electronic part. These parts are manufactured mainly through diecasting process and magnesium ingots are used as raw materials. In the case that ingot quality is not secured, massive casting defects can occur and some manufactures can be damaged by the defects. This study is to evaluate ingots` cleanliness of magnesium alloys. It includes composition analysis by spectrometer, measurement of inclusion contents by SEM, brightness test on fractured surface and etc. Especially, the brightness test is a very easy and quick evaluation method. The brightness becomes low when the amount of oxides or inclusions on the surface increases. The brightness test data have been compared with those obtained from other methods for measuring the mount of impurities, which showed good relationship between the brightness and the others. Thus, the brightness test could be a promising method to measure the cleanliness of magnesium alloys.
{"title":"The Quantitative Evaluation for Impurities of Magnesium Diecasting Alloys","authors":"Hyun Sik Kim, D. Ye, M. Kang, K. Sohn, Hae-Yong Jeong","doi":"10.7777/JKFS.2014.34.1.014","DOIUrl":"https://doi.org/10.7777/JKFS.2014.34.1.014","url":null,"abstract":"Magnesium and its alloys are being applied to various kinds of industrial fields, especially their use on automotive parts and electronic part. These parts are manufactured mainly through diecasting process and magnesium ingots are used as raw materials. In the case that ingot quality is not secured, massive casting defects can occur and some manufactures can be damaged by the defects. This study is to evaluate ingots` cleanliness of magnesium alloys. It includes composition analysis by spectrometer, measurement of inclusion contents by SEM, brightness test on fractured surface and etc. Especially, the brightness test is a very easy and quick evaluation method. The brightness becomes low when the amount of oxides or inclusions on the surface increases. The brightness test data have been compared with those obtained from other methods for measuring the mount of impurities, which showed good relationship between the brightness and the others. Thus, the brightness test could be a promising method to measure the cleanliness of magnesium alloys.","PeriodicalId":16318,"journal":{"name":"Journal of Korea Foundry Society","volume":"41 1","pages":"14-21"},"PeriodicalIF":0.0,"publicationDate":"2014-02-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"91021801","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}
Pub Date : 2013-12-31DOI: 10.7777/JKFS.2013.33.6.233
Heon-Joo Kim, C. Jeong
Effect of Fe and Mn contents on the castability of Al-9wt%Si-xMg-yFe-zMn alloy has been studied. The alloy was composed of α-Al phase, Al+eutectic Si phase, β-Al5FeSi compound and chinese script α-Al15(Mn,Fe)3Si2 compound. β-Al5FeSi and αAl15(Mn,Fe)3Si2 compounds assumed to effect the fluidity and shrinkage behaviors of the alloy during solidification due to the crystallization of α-Al15(Fe,Mn)3Si2 and β-Al5FeSi compounds above eutectic temperature. As Fe and Mn contents of Al-9wt%Si0.3wt%Mg system alloy increased from 0.15wt% to 0.6wt% and from 0.3wt% to 0.7wt%, fluidity of the alloy decreased by 5.7% and 3.3%, respectively. And as Mg content of Al-9wt%Si-0.45wt%Fe-0.5wt%Mn system alloy increased from 0.3wt% to 0.4wt%, fluidity of the alloy decreased by 8.6%. When Fe content of the alloy increased from 0.15wt% to 0.6wt%, macro shrinkage ratio decreased from 6.1% to 4.1%, and micro shrinkage ratio increased from 0.04% to 0.24%. Similarly, Mn content of the alloy increased from 0.3wt% to 0.7wt%, macro shrinkage ratio decreased from 6.0% to 4.5% and micro shrinkage ratio increased from 0.12% to 0.18%. Judging from the castability of the alloy, Al-9wt%Si-0.3wt%Mg alloy with low content of Fe and Mn, 0.1wt% Fe and 0.3wt% Mn, is recommendable.
{"title":"Effect of Fe, Mn Content on the Castability in Al-9wt%Si-Mg System Alloys for High Elongation","authors":"Heon-Joo Kim, C. Jeong","doi":"10.7777/JKFS.2013.33.6.233","DOIUrl":"https://doi.org/10.7777/JKFS.2013.33.6.233","url":null,"abstract":"Effect of Fe and Mn contents on the castability of Al-9wt%Si-xMg-yFe-zMn alloy has been studied. The alloy was composed of α-Al phase, Al+eutectic Si phase, β-Al5FeSi compound and chinese script α-Al15(Mn,Fe)3Si2 compound. β-Al5FeSi and αAl15(Mn,Fe)3Si2 compounds assumed to effect the fluidity and shrinkage behaviors of the alloy during solidification due to the crystallization of α-Al15(Fe,Mn)3Si2 and β-Al5FeSi compounds above eutectic temperature. As Fe and Mn contents of Al-9wt%Si0.3wt%Mg system alloy increased from 0.15wt% to 0.6wt% and from 0.3wt% to 0.7wt%, fluidity of the alloy decreased by 5.7% and 3.3%, respectively. And as Mg content of Al-9wt%Si-0.45wt%Fe-0.5wt%Mn system alloy increased from 0.3wt% to 0.4wt%, fluidity of the alloy decreased by 8.6%. When Fe content of the alloy increased from 0.15wt% to 0.6wt%, macro shrinkage ratio decreased from 6.1% to 4.1%, and micro shrinkage ratio increased from 0.04% to 0.24%. Similarly, Mn content of the alloy increased from 0.3wt% to 0.7wt%, macro shrinkage ratio decreased from 6.0% to 4.5% and micro shrinkage ratio increased from 0.12% to 0.18%. Judging from the castability of the alloy, Al-9wt%Si-0.3wt%Mg alloy with low content of Fe and Mn, 0.1wt% Fe and 0.3wt% Mn, is recommendable.","PeriodicalId":16318,"journal":{"name":"Journal of Korea Foundry Society","volume":"1 1","pages":"233-241"},"PeriodicalIF":0.0,"publicationDate":"2013-12-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"81237419","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}
Pub Date : 2013-12-31DOI: 10.7777/JKFS.2013.33.6.242
H. Yun, Jeong-Min Kim, Joonsik Park, K. Kim, Se-Hyun Ko
The most widely utilized commercial, aluminum-casting alloys are based on an aluminum-silicon system due to its excellent casting, and good mechanical, properties. Unfortunately, these Al-Si based alloys are inherently poor energy conductors; compared to pure aluminum, because of their high silicon content. This means that they are not suitable for applications demanding high eletrical or thermal conductivity. Therefore, efforts are currently being made to develop new, highly-conductive aluminum-casting alloys containing no silicon. In this research, a number of properties; including potential for castability, were investigated for a number of Al-Fe-Zn-Cu alloys with varying Cu content. As the copper content was increased, the tensile strength of Al-Fe-Zn-Cu alloy tended to increase gradually, while the electrical conductivity was slightly reduced. Fluidity was found to be lower in high-Cu alloys, and susceptibility to hot-cracking was generally high in all the alloys investigated.
{"title":"Properties and Casting Capabilities of Al-Fe-Zn-Cu Alloys for High Conductivity Parts","authors":"H. Yun, Jeong-Min Kim, Joonsik Park, K. Kim, Se-Hyun Ko","doi":"10.7777/JKFS.2013.33.6.242","DOIUrl":"https://doi.org/10.7777/JKFS.2013.33.6.242","url":null,"abstract":"The most widely utilized commercial, aluminum-casting alloys are based on an aluminum-silicon system due to its excellent casting, and good mechanical, properties. Unfortunately, these Al-Si based alloys are inherently poor energy conductors; compared to pure aluminum, because of their high silicon content. This means that they are not suitable for applications demanding high eletrical or thermal conductivity. Therefore, efforts are currently being made to develop new, highly-conductive aluminum-casting alloys containing no silicon. In this research, a number of properties; including potential for castability, were investigated for a number of Al-Fe-Zn-Cu alloys with varying Cu content. As the copper content was increased, the tensile strength of Al-Fe-Zn-Cu alloy tended to increase gradually, while the electrical conductivity was slightly reduced. Fluidity was found to be lower in high-Cu alloys, and susceptibility to hot-cracking was generally high in all the alloys investigated.","PeriodicalId":16318,"journal":{"name":"Journal of Korea Foundry Society","volume":"36 8 1","pages":"242-247"},"PeriodicalIF":0.0,"publicationDate":"2013-12-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"78317118","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}
京公网安备 11010802042870号
京ICP备2023020795号-1
扫码关注我们
求助内容：
应助结果提醒方式：