含钪铝合金的开发应用前景

介绍和分析了新型合金化元素钪对铝合金性能的影响和当前含钪铝合金的发展动向及应用前景，同时提出并讨论了我国含钪铝合金的发展战略，建议加速掌握以非高纯氧化钪为原料生产Ａｌ－Ｓｃ中间合金的工业技术和大力开展含钪铝合金的开发应用，尽快把我国含钪铝合金工业的生产体系建立起来。     

钪在铝合金中的应用

本文简介了钪铝合金的制取方法以及它在铝及铝—镁合金中的应用与某些特性。     

钪在铝合金中的作用

介绍了目前Al－Sc合金的研究现状,总结了添加微量钪对铝合金组织和性能的影响,钪在铝合金中可以起到变质剂的作用而使合金的晶粒细化,钪的加入对合金力学性能,焊接性能和耐蚀性能的提高具有重要影响。     

铝钪中间合金的制备技术

钪是铝合金最强的变质剂和加工半成品最有效的抗再结晶剂,添加微量钪可以改善传统铝合金的综合性能。但是钪的熔点高达1541℃,化学性质活泼,制备含钪铝合金时,钪必须以中间合金的形式加入,钪中间合金因此成为制取铝钪合金的关     

钪对2618合金再结晶行为的影响

采用硬度、金相、X射线衍射、透射电镜等测试手段研究了添加钪合金化对2618铝合金再结晶行为的影响。结果表明,添加钪可以明显提高2618铝合金的再结晶温度,而且sc与Al可以生成与铝基体完全共格的细小的Al_3Sc质点。该质点均匀弥散地分布在铝基体上,对位错起强烈的钉扎作用,阻碍晶界迁移,不仅阻碍再结晶软化作用,而且使再结晶晶粒明显细化。实验合金的再结晶形核是通过亚晶粗化的机制而形核的。     

钪、锆对Al-Cu-Mg-Fe-Ni系铝合金显微组织与力学性能的影响

通过添加钪,锆,调整铜量,配制实验合金,采用Ｘ射线衍射,透射电镜,扫描电镜,硬度测量,拉伸试验等手段研究了实验合金挤压棒材组织性能,探讨了含钪,锆的Ａｌ－Ｃｕ－Ｍｇ－Ｆｅ－Ｎｉ系合金的强韧化机理。在２６１８铝合金中添加钪,锆使合金的组织性能得到了明显改善,但钪,锆不宜过量。     

稀土铝合金的研究与应用

添加RE元素可显著改善和提高铝合金的组织结构与综合力学性能。本文主要阐述稀土铝合金尤其是新一代高性能钪铝合金的研究与应用现状。     

加钪对Al-Zn-Mg-Cu-Zr合金组织性能的影响

本文研究了微量钪对Al-Zn-Mg-Cu-Zr合金组织及性能的影响。钪在铝合金中主要以两种形式的化合物存在，一种是合金凝固时从熔体中析出的一次Al2(Sc，Zr)相，另一种是铸锭均匀化时析出的二次Al2(Sc，Zr)相。前者是αa(Al)晶粒细化剂，可有效细化铸态晶粒；后者可强烈牵制晶粒内位错及亚晶界，有效阻止热轧、退火或固溶处理过程中的再结晶。钪是产生强烈析出强化的合金元素，同不加钪的铝合金相比，含0．30％Sc的Al-Zn-Mg-Cu-Zr合金的抗拉强度和延性显著提高。     

稀土在铝合金中的作用及新型含钪铝合金

本文介绍了稀土元素对铝合金熔体净化、变质处理及微合金化的作用，着重阐述了新型含钪铝合金的优异性能及其在尖端工业中的广阔应用前景。     

钪对7005铝合金组织性能的影响

采用金相、透射电镜、扫描电镜、拉伸试验等测试手段，研究了不同含量的稀土元素钪对７００５铝合金组织性能的影响。加入适量钪合金化可以明显细化合金组织，改变主要强化相η相的尺寸、形态、分布，减小晶界无沉淀带宽度，可以明显提高合金强度、塑性以及高温稳定性，这是合金中析出了与铝在体完全共格的Ａｌ３Ｓｃ（ｆｃｃ，α＝０．４１ｍｍ）质点所致。     

铝合金-镁合金间搅拌摩擦异质焊接研究现状

综合了近几年铝-镁搅拌摩擦异质焊的研完成果,分析和讨论以下几个方面的内容:(1)铝.镁异质焊的焊接性能及其影响因素;(2)焊接过程中的热输入情况及焊缝处的温度分布;(3)焊缝的力学性能及其影响因素;(4)焊缝的宏观、微观组织及其在局部升温和塑性变形下的演化过程,着重分析了金属间化合物的生成、形貌和分布、及其对焊缝力学性...     

P/M Al-Zn-Mg-Cu系铝合金中的微量元素

总结P／M Al-Zn-Mg-Cu系铝合金中常用的微量元素和最新进展情况，以及各微量元素在合金中的主要作用，并提出了一些观点和建议。     

Effect of activity differences on hydrogen migration in dissimilar titanium alloy welds

The effect of alloy composition on hydrogen activity was measured for seven titanium alloys as a means to determine the tendency for hydrogen migration within dissimilar metal welds. The alloys were: Ti-CP, Ti-3A1-2.5V, Ti-3Al-2.5V-3Zr, Ti-3Al-2Nb-lTa, Ti-6A1, Ti-6A1-4V, and Ti-6Al-2Nb-lTa-0.8Mo. Hydrogen pressure—hydrogen concentration relationships were determined for temperatures from 600 °C to 800 °C and hydrogen concentrations up to approximately 3.5 at. pct (750 wppm). Fusion welds were made between Ti-CP and Ti-CP and between Ti-CP and Ti-6A1-4V to observe directly the hydrogen redistribution in similar and dissimilar metal couples. Hydrogen activity was found to be significantly affected by alloying elements, particularly Al in solid solution. At a constant Al content and temperature, an increase in the volume fraction of β reduced the activity of hydrogen in α-β alloys. Activity was also found to be strongly affected by temperature. The effect of temperature differences on hydrogen activity was much greater than the effects resulting from alloy composition differences at a given temperature. Thus, hydrogen redistribution should be expected within similar metal couples subjected to extreme temperature gradients, such as those peculiar to fusion welding. Significant hydrogen redistribution in dissimilar alloy weldments also can be expected for many of the compositions in this study. Hydride formation stemming from these driving forces was observed in the dissimilar couple fusion welds. In addition, a basis for estimating hydrogen migration in titanium welds, based on hydrogen activity data, is described.     

Effect of activity differences on hydrogen migration in dissimilar titanium alloy welds

The effect of alloy composition on hydrogen activity was measured for seven titanium alloys as a means to determine the tendency for hydrogen migration within dissimilar metal welds. The alloys were: Ti-CP, Ti-3A1-2.5V, Ti-3Al-2.5V-3Zr, Ti-3Al-2Nb-lTa, Ti-6A1, Ti-6A1-4V, and Ti-6Al-2Nb-lTa-0.8Mo. Hydrogen pressure-hydrogen concentration relationships were determined for temperatures from 600 ‡C to 800 ‡C and hydrogen concentrations up to approximately 3.5 at. pct (750 wppm). Fusion welds were made between Ti-CP and Ti-CP and between Ti-CP and Ti-6A1-4V to observe directly the hydrogen redistribution in similar and dissimilar metal couples. Hydrogen activity was found to be significantly affected by alloying elements, particularly Al in solid solution. At a constant Al content and temperature, an increase in the volume fraction ofΒ reduced the activity of hydrogen in α-@#@ Β alloys. Activity was also found to be strongly affected by temperature. The effect of temperature differences on hydrogen activity was much greater than the effects resulting from alloy composition differences at a given temperature. Thus, hydrogen redistribution should be expected within similar metal couples subjected to extreme temperature gradients, such as those peculiar to fusion welding. Significant hydrogen redistribution in dissimilar alloy weldments also can be expected for many of the compositions in this study. Hydride formation stemming from these driving forces was observed in the dissimilar couple fusion welds. In addition, a basis for estimating hydrogen migration in titanium welds, based on hydrogen activity data, is described.     

稀土在铝和铝合金中应用的研究及进展

稀土元素作为微量元素加入铝及其合金中,不仅有细化晶粒的变质作用,还有净化熔体、减少气体含量及氧化夹杂的精炼效果,从而可显著改善和提高铝及其合金的综合性能.分析讨论了稀土在铝及铝合金中的作用,论述了稀土在铝及铝合金中的开发应用现状,展望了稀土铝合金的发展前景.     

Iron Aluminium Alloys with Strengthening Carbides and Intermetallic Phases for High‐Temperature Applications

An overview of materials developments of iron aluminium alloys with strengthening precipitate phases is given. The discussion is focussed on recent studies on Fe‐Al‐based alloys with strengthening precipitates, such as κ‐phase Fe₃AlC_x, MC‐carbide and Laves phase. Alloys of the following alloy systems were investigated: Fe‐Al‐C, Fe‐Al‐Ta, Fe‐Al‐Ni, Fe‐Al‐Ti‐Nb, and Fe‐Al‐M‐C (M = Ti, V, Nb, Ta). The investigations were centred on microstructure, constitution, and mechanical properties of such Fe‐Al‐based alloys with Al contents ranging from 10 to 30 at. %. Mechanisms and problems are discussed and perspectives are outlined.     

钡系复合合金对钢液脱氧行为的试验研究

在实验室研究的基础上,在LF／VD精炼设备上进行了钡系合金对钢液的脱氧工业试验。试验发现采用SiAlBaCa脱氧时的全氧含量基本上在各个工位均低于采用Al和FeSiAl脱氧,其脱氧产物上浮速度要快于用Al脱氧,能够较快地使夹杂物数量达到较低的水平,且试验中夹杂物的球化作用比较明显,同时还探讨了钡系合金脱氧和对夹杂物的变质作用机理。     

Acid Refining of Synthesised Alloys Within the Quaternary System Fe–Si–Ca–AI: Effect of Ferric Ions

A systematic study of synthesis of different chemical composition of alloys within the quaternary Fe–Si–Ca–Al system, versus acid leaching refining using HCl with or without FeCl₃ has been undertaken. Such study has the aim of achieving an adequate structural composition of Fe–Si alloys, in order to obtain high purity and fine particle size silicon by acid leaching, at more reduced costs. The experimental results show that an adequate control of Fe/Al and Si/Ca concentration ratios can hinder the formation of tetragonal and orthorhombic FeSi₂ phases, and consequently promotes a successful refining of ferro-silicon alloys. The presence of ferric ion influences on a distinct way the rate of removal of Al–Fe–Si and Fe–Al–Si–Ca phases, increasing the first and decreasing the second one. The suitable starting composition which could give the expected results must be the following: 92–94% Si; 3–3.5% Fe; 3.5–4% Al and Ca ≤ 0.5%.     

Influence of CO on PCT Properties of LaNi_5, LaNi_(4.7)Al_(0.3) and MlNi_(4.5)Al_(0.5) Alloys

Influence of CO on PCT Properties of LaNi_5, LaNi_(4.7)Al_(0.3) and MlNi_(4.5)Al_(0.5) Alloys