Journal of Light Metals最新文献

{"title":"Formation of defect bands in high pressure die cast magnesium alloys","authors":"A.K Dahle ,&nbsp;S Sannes ,&nbsp;D.H St. John ,&nbsp;H Westengen","doi":"10.1016/S1471-5317(01)00002-5","DOIUrl":"https://doi.org/10.1016/S1471-5317(01)00002-5","url":null,"abstract":"<div><p>Die cast magnesium components are being increasingly used worldwide because of the excellent castability and properties that magnesium alloys offer. High pressure die casting of thin-walled components is particularly suitable because of the excellent flow characteristics of molten magnesium alloys. Typical automotive applications for thin-walled castings include components such as instrument panels, steering wheels, door frames and seat frames. These applications require optimisation of the quality and performance of the castings. It has been found that bands of porosity or segregation which follow contours parallel to the surface of the casting are formed under certain casting conditions in thin-walled magnesium high pressure die castings. The presence of this type of defect can have a significant effect on the mechanical properties. This paper investigates the effect of varied casting conditions on casting integrity and the appearance of the bands. A rationale for understanding the origin of these defects is related to the solidification behaviour, the mushy zone rheological properties and the filling pattern of the casting with associated shearing of the mushy zone. Methods to optimise the process parameters to control the occurrence of the banded defects, and thereby optimise the quality of high pressure die cast magnesium components, are outlined.</p></div>","PeriodicalId":100798,"journal":{"name":"Journal of Light Metals","volume":"1 2","pages":"Pages 99-103"},"PeriodicalIF":0.0,"publicationDate":"2001-05-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1016/S1471-5317(01)00002-5","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"72111150","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":"An assessment of the instability of Ti and its alloys in acidic environments at elevated temperature","authors":"Anne Neville,&nbsp;Jie Xu","doi":"10.1016/S1471-5317(01)00005-0","DOIUrl":"https://doi.org/10.1016/S1471-5317(01)00005-0","url":null,"abstract":"<div><p>The effect of temperature in the range from 20 to 100 °C on the corrosion activity of Ti alloys in three different solutions [HCl of pH=4, (HCl<!--> <!-->+<!--> <span>500 ppm NaCl) of pH=4 and HCl of pH=2] was studied by DC electrochemical testing methods. Potentiostatic tests and measurement of the free corrosion potential (</span><em>E</em>_corr) were employed, in conjunction with microscopical analysis, to investigate the localised instability of four materials. It was found that pitting is the main localised corrosion type for commercially pure (CP) Ti and Ti alloys in HCl. A critical pitting temperature (CPT) was defined for the different materials. Observation of the passive current transients before the CPT is reached indicate that corrosion `events' occur throughout the increasing temperature phase and that these `events' are dependent on the material and environment.</p></div>","PeriodicalId":100798,"journal":{"name":"Journal of Light Metals","volume":"1 2","pages":"Pages 119-126"},"PeriodicalIF":0.0,"publicationDate":"2001-05-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1016/S1471-5317(01)00005-0","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"72111153","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":"The Alstruc homogenization model for industrial aluminum alloys","authors":"Anne Lise Dons","doi":"10.1016/S1471-5317(01)00007-4","DOIUrl":"https://doi.org/10.1016/S1471-5317(01)00007-4","url":null,"abstract":"<div><p><span>Wrought aluminum alloys<span> are often given a homogenization heat treatment before extrusion or rolling. Foundry alloys are sometimes given a solution heat treatment before age hardening. The purpose is</span></span></p><ul><li><span>•</span><span><p>to remove particles and segregation gradients that will give films or areas with low melting temperatures, in order to avoid tearing during extrusion and rolling;</p></span></li><li><span>•</span><span><p>to round off hard particles with sharp edges, which give poor ductility and holes in thin walled products;</p></span></li><li><span>•</span><span><p>to form secondary particles (dispersoids) for grain size control during extrusion and rolling;</p></span></li><li><span>•</span><span><p>to obtain a uniform distribution of alloying elements in solid solution before rolling, extrusion or age hardening.</p></span></li></ul>\u0000The Alstruc homogenization program gives semi-quantitative estimates of the changes in the microstructure during the later part of the heating stage and during the holding stage. The program has separate subroutines for AA3xxx (AlMnFe with Mg and Si), AA5xxx (AlMg with Fe, Si and Mn) and AA6xxx (AlMgSi with Fe, Mn and Cu) wrought alloys and for AlSi foundry alloys with Fe, Mg and Cu. The estimates of the changes in the microstructure during cooling are qualitative.<p>This paper is compiled of three parts: <span>1 Industrial homogenization process for aluminum alloys</span>, <span>2 The homogenization process – structural perspective</span>, <span>3 The homogenization process – modeling needs</span>, <span>4 Homogenization model development</span>, <span>5 Experimental comparison and verification of Alstruc for AA6xxx-alloys</span> present the program concept, <span>6 Experimental Comparison and verification of Alstruc for AA3xxx-alloys</span>, <span>7 Experimental comparison and verification of Alstruc for AlSi foundry alloys</span>, <span>8 Industrial alloys: aluminum corner of the solid-state AlMgMnFeSiCu phase diagram</span> present the results of the curve fitting and verification process for industrial alloys, and <span>Section 9</span> presents interesting phase diagrams.<span><div><div><table><tbody><tr><td>Solidification</td><td>Homogenization</td></tr><tr><td>AA1xxx</td><td></td></tr><tr><td>AA3xxx</td><td>AA3xxx</td></tr><tr><td>AA5xxx</td><td>(AA5xxx)</td></tr><tr><td>AA6xxx</td><td>AA6xxx</td></tr><tr><td>AA7xxx</td><td></td></tr><tr><td><span><math><mtext>AlSi</mtext></math></span>+++</td><td><span><math><mtext>AlSi</mtext></math></span>+++</td></tr></tbody></table></div></div></span></p></div>","PeriodicalId":100798,"journal":{"name":"Journal of Light Metals","volume":"1 2","pages":"Pages 133-149"},"PeriodicalIF":0.0,"publicationDate":"2001-05-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1016/S1471-5317(01)00007-4","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"72111131","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":"A thermochemical analysis of the production of anhydrous MgCl2","authors":"Georges J. Kipouros ,&nbsp;Donald R. Sadoway","doi":"10.1016/S1471-5317(01)00004-9","DOIUrl":"https://doi.org/10.1016/S1471-5317(01)00004-9","url":null,"abstract":"<div><p>The electrolytic production of magnesium requires high-purity, anhydrous magnesium chloride which has a high affinity for water and is found in nature as a plurality of hydrates (MgCl₂·<em>n</em>H₂O, <em>n</em>=1, 2, 4, 6, 8, 12). Their dehydration is nontrivial and can be accompanied by hydrolysis leading to the production of undesirable oxycompounds of magnesium. Through an analysis of the relevant thermochemistry this paper indicates how to prevent hydrolysis and make electrolytic-grade, anhydrous MgCl₂.</p></div>","PeriodicalId":100798,"journal":{"name":"Journal of Light Metals","volume":"1 2","pages":"Pages 111-117"},"PeriodicalIF":0.0,"publicationDate":"2001-05-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1016/S1471-5317(01)00004-9","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"72111152","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":"An assessment of the instability of Ti and its alloys in acidic environments at elevated temperature","authors":"A. Neville, Jie Xu","doi":"10.1016/S1471-5317(01)00005-0","DOIUrl":"https://doi.org/10.1016/S1471-5317(01)00005-0","url":null,"abstract":"","PeriodicalId":100798,"journal":{"name":"Journal of Light Metals","volume":"300 1","pages":"119-126"},"PeriodicalIF":0.0,"publicationDate":"2001-05-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"75112715","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":"A thermochemical analysis of the production of anhydrous MgCl2","authors":"G. Kipouros, D. Sadoway","doi":"10.1016/S1471-5317(01)00004-9","DOIUrl":"https://doi.org/10.1016/S1471-5317(01)00004-9","url":null,"abstract":"","PeriodicalId":100798,"journal":{"name":"Journal of Light Metals","volume":"65 1","pages":"111-117"},"PeriodicalIF":0.0,"publicationDate":"2001-05-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"91149504","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":"Fabrications and mechanical properties of bulk amorphous, nanocrystalline, nanoquasicrystalline alloys in aluminum-based system","authors":"Akihisa Inoue,&nbsp;Hisamichi Kimura","doi":"10.1016/S1471-5317(00)00004-3","DOIUrl":"https://doi.org/10.1016/S1471-5317(00)00004-3","url":null,"abstract":"<div><p><span>By controlling the composition, clustered atomic configuration and stability of supercooled liquid by the rapid solidification and </span>powder metallurgy techniques, high-strength Al-based bulk alloys containing nanoscale nonperiodic phases were produced in Al–Ln–LTM, Al–ETM–LTM and Al–(V, Cr, Mn)–LTM (Ln=lanthanide metal, LTM=VII and VIII group transition metals, ETM=IV–VI group transition metals) alloys containing high Al contents of 92–95 at.%. The nonperiodic phases are composed of an amorphous or an icosahedral quasicrystalline phase. In particular, the Al-based bulk alloys consisting of nanoscale icosahedral particles surrounded by fcc-Al phase exhibit much better mechanical properties exceeding largely those for the commercial high-strength type Al-based alloys. The success of producing the Al-based alloys with good engineering properties by use of the icosahedral phase is promising for future development of icosahedral base alloy as practical materials.</p></div>","PeriodicalId":100798,"journal":{"name":"Journal of Light Metals","volume":"1 1","pages":"Pages 31-41"},"PeriodicalIF":0.0,"publicationDate":"2001-02-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1016/S1471-5317(00)00004-3","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"72113879","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":"The role of plastic deformation on the competitive microstructural evolution and mechanical properties of a novel Al–Li–Cu–X alloy","authors":"B.M Gable,&nbsp;A.W Zhu,&nbsp;A.A Csontos,&nbsp;E.A Starke Jr.","doi":"10.1016/S1471-5317(00)00002-X","DOIUrl":"https://doi.org/10.1016/S1471-5317(00)00002-X","url":null,"abstract":"<div><p><span>The role of plastic deformation<span> prior to artificial aging on the microstructural evolution<span><span> and mechanical properties of a novel Al–Li–Cu–X alloy designated AF/C 458 was investigated. Induced plastic deformation ranged from a non-stretched or 0% stretch condition to an 8% stretch, with intermediate stretches of 2%, 4% and 6%. Tensile properties, </span>fractography and quantitative precipitate analysis were acquired from specimens that were water quenched from a solution heat treatment, immediately stretched and artificially aged at 150°C. Fractography was investigated through scanning electron microscopy (SEM). Quantitative transmission electron microscopy (TEM) determined the variation in precipitate type, number density, size and volume fraction of the major strengthening precipitates Al</span></span></span>₂CuLi (<em>T</em>₁), Al₂Cu (<em>θ</em>″/<em>θ</em>^′) and Al₃Li (<em>δ</em>^′).</p><p>Age hardening curves for each level of mechanical stretch illustrated the enhanced aging kinetics of plastically deformed material. Quantitative TEM indicated that increasing amounts of pre-age stretch were found to greatly affect the competitive precipitation kinetics of <em>T</em>₁ and <em>θ</em>″/<em>θ</em>^′ in AF/C 458 augmenting the volume fraction of fine matrix <em>T</em>₁ plates and dramatically decreasing the volume fraction of <em>θ</em>″/<em>θ</em>^′ for isochronal treatments. A quantitative microstructural comparison of specimens exhibiting a given strength demonstrated that the imposed level of cold work dictated the density, size and volume fraction of the competing precipitates. The tensile data indicated a trend of increasing ductility for equivalent yield strengths with the increasing amount of pre-age mechanical stretch and therefore shorter artificial aging times. The quantitative precipitate data were used with a computer simulation for yield strength determination. The theoretical simulation reported calculated yield strengths in good accord with experimental results and can thus be used to predict the optimum microstructural configuration for high strength.</p></div>","PeriodicalId":100798,"journal":{"name":"Journal of Light Metals","volume":"1 1","pages":"Pages 1-14"},"PeriodicalIF":0.0,"publicationDate":"2001-02-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1016/S1471-5317(00)00002-X","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"72117066","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":"Modeling microporosity in aluminum–silicon alloys: a review","authors":"P. Lee, A. Chirazi, D. See","doi":"10.1016/S1471-5317(00)00003-1","DOIUrl":"https://doi.org/10.1016/S1471-5317(00)00003-1","url":null,"abstract":"","PeriodicalId":100798,"journal":{"name":"Journal of Light Metals","volume":"103 1","pages":"15-30"},"PeriodicalIF":0.0,"publicationDate":"2001-02-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"90343330","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":"Development of the as-cast microstructure in magnesium-aluminium alloys","authors":"A. Dahle, Y. C. Lee, M. Nave, P. Schaffer, D. StJohn","doi":"10.1016/S1471-5317(00)00007-9","DOIUrl":"https://doi.org/10.1016/S1471-5317(00)00007-9","url":null,"abstract":"","PeriodicalId":100798,"journal":{"name":"Journal of Light Metals","volume":"29 1","pages":"61-72"},"PeriodicalIF":0.0,"publicationDate":"2001-02-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"76999182","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}