Journal of Light Metals最新文献_第6页

Influence of alloying elements on the thermal analysis results of Al–Si cast alloys 合金元素对铝硅铸造合金热分析结果的影响

Journal of Light Metals Pub Date : 2002-02-01 DOI: 10.1016/S1471-5317(02)00009-3

Leonhard Heusler, Wolfgang Schneider

{"title":"Influence of alloying elements on the thermal analysis results of Al–Si cast alloys","authors":"Leonhard Heusler, Wolfgang Schneider","doi":"10.1016/S1471-5317(02)00009-3","DOIUrl":"https://doi.org/10.1016/S1471-5317(02)00009-3","url":null,"abstract":"<div>Knowledge about the influence of alloying elements on the eutectic temperature and the eutectic depression is essential for assessing the quality of a modification treatment by means of thermal analysis. In this work, the influence of magnesium on sodium and strontium modification was studied while the effects of Si, Cu and Fe were investigated for sodium modification. In addition, the evaluation methods of different commercial thermal analysis systems were studied critically with respect to the determination of the eutectic reference temperature of the non-modified melt. This is usually done by means of equations from literature. These equations consider the effect of alloying elements on the eutectic temperature.Magnesium is shown to affect the depression values in a different way from that expected up to now. The eutectic depression is found to fall substantially with an increasing Si content and to increase with a growing Cu content while the effect of iron was not very pronounced. Thermal analysis systems which calculate the eutectic reference temperature by means of equations from literature may show systematic errors due to different cooling conditions in the thermal analysis experiment. Setting up these empirical equations with experiments at the right cooling rates leads to a very good agreement with the estimated and measured reference temperatures. Systems where ternary reactions in the cooling curves are used to estimate the concentrations of the corresponding elements proved to be unsuccessful because the effects of the alloying element on the cooling curve were not detected correctly.</div>","PeriodicalId":100798,"journal":{"name":"Journal of Light Metals","volume":"2 1","pages":"Pages 17-26"},"PeriodicalIF":0.0,"publicationDate":"2002-02-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1016/S1471-5317(02)00009-3","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"72108601","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: 80

Characterisation of protective surface films formed on molten magnesium protected by air/SF6 atmospheres 由空气/SF6气氛保护的熔融镁上形成的保护性表面膜的特性

Journal of Light Metals Pub Date : 2002-02-01 DOI: 10.1016/S1471-5317(02)00011-1

S.P Cashion , N.J Ricketts , P.C Hayes

{"title":"Characterisation of protective surface films formed on molten magnesium protected by air/SF6 atmospheres","authors":"S.P Cashion , N.J Ricketts , P.C Hayes","doi":"10.1016/S1471-5317(02)00011-1","DOIUrl":"https://doi.org/10.1016/S1471-5317(02)00011-1","url":null,"abstract":"<div>Magnesium metal in its molten state will oxidise rapidly in air, leading to burning on the melt surface. In order to process molten magnesium safely, the melt is protected from oxidation by blanketing the surface with a cover gas. The cover gas reacts with the metal and forms a protective film on the melt surface. Sulphur hexafluoride (SF6) is widely used by the magnesium industry as a component of cover gas mixtures. However, the use of SF6 has come under increased scrutiny due to its high cost and, more importantly, its significant impact on the greenhouse effect. To optimise the use of SF6, a detailed knowledge of its role in protecting molten magnesium is required. This paper describes the characterisation of the surface films formed on molten magnesium protected by cover gas mixtures containing SF6. Sensitive surface analysis techniques have been used to quantitatively determine the chemical attributes of the films. XPS showed that the film contains only MgO and MgF2. No sulphur compounds were detected. AES depth profiling indicated film thickness to be in the range 0.1–1 μm.</div>","PeriodicalId":100798,"journal":{"name":"Journal of Light Metals","volume":"2 1","pages":"Pages 37-42"},"PeriodicalIF":0.0,"publicationDate":"2002-02-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1016/S1471-5317(02)00011-1","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"72108605","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: 67

The effect of zirconium grain refinement on the corrosion behaviour of magnesium-rare earth alloy MEZ 锆晶粒细化对镁稀土合金MEZ腐蚀行为的影响

Journal of Light Metals Pub Date : 2002-02-01 DOI: 10.1016/S1471-5317(02)00008-1

G. Song, D. StJohn

引用次数: 211

Influence of alloying elements on the thermal analysis results of Al–Si cast alloys 合金元素对铝硅铸造合金热分析结果的影响

Journal of Light Metals Pub Date : 2002-02-01 DOI: 10.1016/S1471-5317(02)00009-3

L. Heusler, W. Schneider

引用次数: 79

Effect of a short solution treatment time on microstructure and mechanical properties of modified Al–7wt.%Si–0.3wt.%Mg alloy 短固溶处理时间对改性Al–7wt.%微观结构和力学性能的影响Si–0.3wt.%镁合金

Journal of Light Metals Pub Date : 2002-02-01 DOI: 10.1016/S1471-5317(02)00010-X

D.L Zhang , L.H Zheng , D.H StJohn

{"title":"Effect of a short solution treatment time on microstructure and mechanical properties of modified Al–7wt.%Si–0.3wt.%Mg alloy","authors":"D.L Zhang , L.H Zheng , D.H StJohn","doi":"10.1016/S1471-5317(02)00010-X","DOIUrl":"https://doi.org/10.1016/S1471-5317(02)00010-X","url":null,"abstract":"<div>Microstructural change caused by a short solution treatment and the corresponding change in tensile properties and impact energy of a strontium modified Al–7wt.%Si–0.3%Mg cast alloy were studied. It was found that a solution treatment of 10 min at 540 or 550 °C is sufficient for the α-aluminium phase to homogenise and achieve the maximum level of magnesium and silicon as predicted by the solubility and alloy composition limits. A solution treatment of 30 min causes spheroidisation, coarsening and an increase in inter-particle spacing of the eutectic silicon particles leading to a significant improvement in ductility and impact resistance. Compared with a standard 6 h solution treatment, solution treatment of 30 min at 540 or 550 °C is sufficient to achieve more than 90% of the maximum yield strength and more than 95% of the maximum UTS and the maximum average elongation to fracture. However, only 80% of the maximum impact energy can be attained by the short solution treatment. The values of the ductility and impact energy pass through a minimum between 1.5 and 10 min of solution treatment time indicating that solution treatments of less than 10 min should be avoided.</div>","PeriodicalId":100798,"journal":{"name":"Journal of Light Metals","volume":"2 1","pages":"Pages 27-36"},"PeriodicalIF":0.0,"publicationDate":"2002-02-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1016/S1471-5317(02)00010-X","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"72108602","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: 152

The elastic modulus of cast Mg–Al–Zn alloys 铸造Mg–Al–Zn合金的弹性模量

Journal of Light Metals Pub Date : 2002-02-01 DOI: 10.1016/S1471-5317(02)00013-5

T. Sumitomo , C.H. Cáceres , M. Veidt

引用次数: 57

The elastic modulus of cast Mg–Al–Zn alloys 铸造Mg-Al-Zn合金的弹性模量

Journal of Light Metals Pub Date : 2002-02-01 DOI: 10.1016/S1471-5317(02)00013-5

T. Sumitomo, C. H. Cáceres, M. Veidt

引用次数: 57

Characterisation of protective surface films formed on molten magnesium protected by air/SF6 atmospheres 空气/SF6环境下熔镁表面保护膜的表征

Journal of Light Metals Pub Date : 2002-02-01 DOI: 10.1016/S1471-5317(02)00011-1

S. Cashion, N. Ricketts, P. Hayes

引用次数: 67

The mechanism of protection of molten magnesium by cover gas mixtures containing sulphur hexafluoride 含六氟化硫气体混合物保护熔融镁的机理

Journal of Light Metals Pub Date : 2002-02-01 DOI: 10.1016/S1471-5317(02)00012-3

S. Cashion, N. Ricketts, P. Hayes

引用次数: 51

The effect of zirconium grain refinement on the corrosion behaviour of magnesium-rare earth alloy MEZ 锆晶粒细化对镁-稀土合金MEZ腐蚀行为的影响

Journal of Light Metals Pub Date : 2002-02-01 DOI: 10.1016/S1471-5317(02)00008-1

Guangling Song, David StJohn

{"title":"The effect of zirconium grain refinement on the corrosion behaviour of magnesium-rare earth alloy MEZ","authors":"Guangling Song, David StJohn","doi":"10.1016/S1471-5317(02)00008-1","DOIUrl":"https://doi.org/10.1016/S1471-5317(02)00008-1","url":null,"abstract":"<div>Corrosion performance of sand cast magnesium alloy MEZ was investigated for unrefined (MEZU) and Zr-grain-refined (MEZR) microstructures in 5% NaCl solution using salt spray, immersion, in situ examination of the corrosion morphology, ESEM, electron probe microanalysis, hydrogen evolution and polarisation curves. MEZU demonstrated higher rates of anodic dissolution and cathodic hydrogen evolution than MEZR. The central zirconium-rich areas within the grains of the MEZR microstructure was more corrosion resistant than the outer zirconium-depleted areas of the grains, whereas MEZU showed little difference in corrosion between the centre and the edge of the grains. Based on the analyses of the corrosion process, polarisation behaviour and the microstructure of these two alloys, it is postulated that zirconium acts in a number of ways to improve corrosion resistance. Zirconium stabilises the solid solution and makes it inactive in anodic dissolution, significantly passivates the precipitated particles reducing cathodic hydrogen evolution and increases the barrier effect of the grain boundary phase through a finer grain size and thus a more continuous layer of the grain boundary phase.</div>","PeriodicalId":100798,"journal":{"name":"Journal of Light Metals","volume":"2 1","pages":"Pages 1-16"},"PeriodicalIF":0.0,"publicationDate":"2002-02-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1016/S1471-5317(02)00008-1","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"72115828","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: 215