AlTiB中间合金熔体结构的DSC分析

通过DSC分析初步探讨了A15TilB中间合金的熔体结构,试验结果表明:AlTiB中间合金熔体结构是微观不均匀的,即含有未溶解的并保持原始固态组织形态的TiAl_3晶体和TiB_2相颗粒。另外,在某一临界温度下,存在着结构转变,初步绘制了AlTiB中间合金的液态相图,快速凝固组织分析进一步证实了这一结构转变。     

AlTiB中间合金细经行为的温度特性

研究了温度对ＡｌＴｉＢ中中金细化效果的影响。试验结果表明,ＡｌＴｉＢ中间合金的 效果不仅取决人于其本身的结构形态,而且与细化工业纯铝的温度密切相关。比较了国内外三种ＡｌＴｉＢ中间合金的细化效果随温度的变化规律,发现,其变化规律和达到最佳细化效果不同。     

AlTiB中间合金细化行为的温度特性

研究了温度对 Ａｌ Ｔｉ Ｂ 中间合金细化效果的影响。试验结果表明， Ａｌ Ｔｉ Ｂ 中间合金的细化效果不仅取决于其本身的结构形态， 而且与细化工业纯铝的温度密切相关。比较了国内外三种 Ａｌ Ｔｉ Ｂ中间合金的细化效果随温度的变化规律， 发现， 其变化规律和达到最佳细化效果不同。     

细化铝晶粒AlTiB中间合金的质量要求（1）

由于在铝材深度加工工业中对质量要求的增高,所以用AlTiB中间合金来细化塑性铝合金的工艺又被提到突出的地位.中间合金应根据各自的使用目的来满足规定的质量要求,藉此可将在进一步深度加工的产品中引起缺陷的危险性降到尽量小的程度.在本文的第一部分里,将围绕质量要求来报道有关标准规范.     

用ICP-AES法快速测定Al-Ti中间合金和AlTiB晶粒细化剂中的Ti含量

建立了一种快速测定Al-Ti中间合金、AlTiB晶粒细化剂中Ti元素含量的分析方法。采用铝基体进行匹配,通过与分光光度法进行对比试验。结果表明,本方法可以达到快速测定Ti含量的目的。两种方法的绝对误差和相对误差均在允差范围内。     

AlTiB中间合金细化效果的组织遗传效应

通过对比试验发现：不同组织的Ａｌ－５Ｔｉ－１Ｂ中间合金具有不同的细化效果。借助金相，ＳＥＭ和ＴＥＭ等手段对组织进行了分析对比，探讨组织遗传对细化效果的影响。实验结果表明：利用快速凝固法制备的该中间合金，其块状ＴｉＡｌ３化合物细小，ＴｉＢ２等微小粒子分布弥散，具有最佳的细化效果。     

细化铝晶粒的AlTiB中间合金的质量要求（2）

本文的第二部分主要论述几种中间合金细化晶粒的效果,从极为重要的质量规范来看组织的形成.目前的结果多数是在对AlTi5B1和AlTi3Bl中间合金进行试验和质量控制的研究基础上获得的.     

杆状AlTiB中间合金的组织形貌及晶粒细化行为的研究

杆状ＡｌＴｉＢ中间合金是铝及其合金连铸过程中最常用的晶粒细化剂。本文采用Ｘ射线衍射和晶粒细化对比试验对国内外杆状ＡｌＴｉＢ中间合金进行了全面分析，发现它们的组成相均为α－Ａｌ＋ＴｉＡｌ３＋ＴｉＢ２。但国内产品的钛含量及ＴｉＢ２、ＴｉＡｌ３相含量偏低，晶粒细化效果很差。自行研制的ＡｌＴｉＢ中间合金的钛含量和ＴｉＢ２、ＴｉＡｌ３相含量与国外产品相当，晶粒细化效果也可与之媲美。探讨了ＡｌＴｉＢ中间合金在铝及铝合金中的形核机理。     

AlTiC中间合金细化剂研究的最新进展

通过合适的工艺、并选择合适的成分,AlTiC对99.7％Al的细化效果完全可以和目前国际上最好的AlTiB相媲美。当细化1070、1060、1235、3004、6063及8011等合金时,AlTiC和AlTiB细化效果均优异且相当。当用对99.7％Al具有同样细化效果的AlTiC和AlTiB细化含Zr、Cr、Mn的铝合金时,未发现细化“中毒”现象,Zr和Mn还不同程度地加强了AlTiC和AlTiB的细化效果。TiC单独成为结晶核心的观点成立与否与TiC的加入方式和保温时间同时相关;用不含Al3Ti的AlTiC细化剂细化工业纯铝时,在保温60min时间内,这样的AlTiC可产生一定的细化效果;用纯TiC粉直接加入铝液时,当TiC粉在铝液中分散均匀后,即可产生显著的晶粒细化效果。     

AlTiB中间合金中TiAl3形态的遗传与变异

对两种ＴｉＡｌ３形态的ＡｌＴｉＢ中间合金的重熔试验表明：ＴｉＡｌ３晶体形态在１０００℃以下有明显遗传性；过热至１１００℃时ＴｉＡｌ３晶体形态发生变异，原先为块状的ＴｉＡｌ３晶体转变为针片状，原先为针片状的ＴｉＡｌ３晶体则变厚变短，有转化为块状的倾向。     

AlTiB晶粒细化剂微观组织的电镜观察

简要概括了AlTiB合金细化剂生产中影响其质量的几个环节.采用非腐蚀方法制备试样,保持样品真实的状态.在扫描电镜下观察了铸态、加工变形后中间合金微观组织的变化,得到一些更详细的信息.概括了以前一些细化机制.讨论了TiAl3、TiB2粒子在晶粒细化过程中可能起的作用;并把"表面重构"和"过渡层"的概念引入到AlTiB中间合金细化剂细化机制的讨论中.     

Performance comparison of AlTiC and AlTiB master alloys in grain refinement of commercial and high purity aluminum

1 Introduction Since AlTiC master alloys were improved greatly as a new type of master alloy used in grain refinement of aluminum and aluminum alloys in the middle of 1980s[1, 2], there were many important progresses in the preparation techniques and the …     

Grain refinement of AZ31 magnesium alloy by new Al-Ti-C master alloys

New Al₄C₃-containing Al-Ti-C master alloys (Al-0.6Ti-1C and Al-1Ti-1C) were developed by introducing Ti element into Al-C melt using melt reaction method, in which most of the TiC particles distribute around Al₄C₃ particles. It is believed that most of the C firstly reacts with Al melt and form Al₄C₃ particles by the reaction Al(l)+C(s)→Al₄C₃(s), and after adding Ti into the Al-C melt, the size of Al₄C₃ particles is decreased and the distribution of Al₄C₃ is improved through the reaction Ti(solute)+Al₄C₃(s)→TiC(s)+Al(l). With the addition of 1% Al-1Ti-1C master alloy, the average grain size of AZ31 is reduced sharply from 850 μm to 200 μm, and the grain morphology of α-Mg transits from a fully-developed equiaxed dendritic structure to a petal-like shape. Al-C-O-Mn-Fe compounds are proposed to be potent nucleating substrates for primary Mg. Appropriate addition of Ti is believed to increase the grain refinement efficiency of Al₄C₃-containing Al-Ti-C master alloys in AZ31 alloy.     

Quality assessment of aluminum-based grain refining master alloys

1. IntroductionThe improvement of the properties of aluminumproducts is still a real problem in the theory and practiceof foundry. It can be solved by different methods includinggrain refinement, which is considered to be one of themost effective, simple and reliable methods. A grain refineris known to contain numerous high-melting particles,which are released after the aluminum matrix dissolves ina melt and subsequently act as heterogeneous nuclei oncooling. It provides a fine equiaxed grain …     

Al-Mg-Sc中间合金的制备

在非真空条件下用氟化物熔盐体系镁 (铝 )热还原法制备了Al Mg Sc中间合金 ,讨论了金属还原剂的选择及还原温度、时间等工艺条件对钪收率的影响 ,并研究制定了氧化钪固相氟化制备氟化钪熔盐工艺。采用Al Mg合金熔体为还原剂经二次还原后钪收率 >80 %,制备的Al Mg Sc中间合金铸锭中钪含量 >1.9%,最佳的还原反应温度为 110 0K ,还原时间 40min .。氟化钪还原产生的初生态钪与铝作用形成稳定的Al3 Sc化合物 ,促进了还原的进行 ,使钪收率得到了大幅度提高。     

Thermodynamic calculation on metallic thermoreduction during preparation of aluminum-rare master alloys

1　ＩＮＴＲＯＤＵＣＴＩＯＮＲｅｃｅｎｔｌｙａｌｕｍｉｎｕｍ ｒａｒｅｍｅｔａｌａｌｌｏｙｓａｔｔｒａｃｔｍｕｃｈｉｎｔｅｒｅｓｔ.Ｍｅｔａｌｌｉｃｔｈｅｒｍｏｒｅｄｕｃｔｉｏｎ ,ｉｎｗｈｉｃｈｏｘｉｄｅｓａｎｄｃｈｌｏｒｉｄｅｓｏｆｒａｒｅｍｅｔａｌａｒｅｒｅｄｕｃｅｄａｎｄｉｎ ｓｉｔｕａｌｌｏｙｅｄｂｙａｌｕｍｉｎｕｍ ,ｈａｓｔｈｅｂｅｓｔｐｒｏｓｐｅｃｔｉｎａｌｌｐｒｏｄｕｃｔｉｏｎｍｅｔｈｏｄｓｏｆａｌｕｍｉｎｕｍ ｒａｒｅｍｅｔａｌａｌｌｏｙｓ .Ｈｏｗｅｖｅｒｔｈｉｓｍｅｔｈｏｄｉｓｍｏ…     

金属热还原法制备V-Ti-Fe中间合金(英文)

采用金属热还原热法制备V-Ti-Fe中间合金,考察V2O5与TiO2的加入比例、用铝量和Al-Mg合金用量对金属回收率和合金成分的影响。结果表明:最佳工艺参数为原料中V2O5和TiO2的质量比为0.5:1,实际用铝量为理论值的95%,Al-Mg合金用量为铝量的1/3。能谱分析结果表明,合金中的V和Fe元素分布比较均匀,Ti则存在一定偏析。为降低合金中Al和O的杂质含量,进行喷吹造渣精炼。精炼后,合金中的铝含量由4.27%降为1.86%,氧含量由2.10%降为0.91%。     

Structural heredity between Al5Ti1B and AlTi, AlB master alloys

1INTRODUCTIONAl5TilBmasteralloyiswidelyusedinalu-minumindustryasahighlyeffectivegrainrefin-.,[1~4],itusuallycontainsTiAl3andTiB2parti-clesinanAl..t.i.[5'6J,amongothersTiB2particlesactasnucleantsofa(Al),whileTiAl3particlesaredissolvedinAlmeltandpromotetheformationofTiB2...l...t,L7,8].SOmetimes,Al5Ti1BmasteralloycontainscertainAlB2parti-cleswhenitisproducedbyfirstaddingKBF4a11dthenK,TiF,['],thiswillinfluenceitsgrainrefiningefficency.ThepreparingmethodsofAl5Ti1Bmasteralloymainlyi…     

Grain refining of Al-Si alloys using Al-10% Ti master alloy: role of Zr addition

The present study was carried out on ultra-pure aluminum, 1050, and 356 alloys. The results revealed that when Al-4%B is added to ultra-pure aluminum, it forms AlB₁₂ and AlB₂ which have no grain refining effect in pure aluminum. When no grain refiner is added to pure aluminum, the microstructure is a mixture of columnar and equiaxed grains. The addition of 30 ppm Ti to pure aluminum is sufficient to promote equiaxed grains when the metal is solidified at high rate ~ 10°C/s but requires an addition of 1000 ppm B at 0.8°C. Increasing the Si content to 7% reduces the initial grain size of pure aluminum from 2800 μm to 1200 μm. In commercial aluminum, B reacts with traces of Ti to form TiB₂ phases which are active grain refining agents. However, in Al-7%Si, Ti reacts with Si forming (Al,Si)₂Ti phase which is a poor refining agent.