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。     

Sc对Al-Mg合金组织和性能的影响

采用金相显微镜，扫描电镜（SEM）和力学性能检测等方法，研究了微量Sc对Al-5%Mg合金显微组织，力学性能和断口形貌的影响，结果表明，添加0．17％Sc的合金铸态组织得到显著细化，枝晶组织在相当程度上得到消除，直到575℃合金仍然保持着大量的变形组织，添加钪的合金在高温退火后可以保留较高的强度，但合金塑性比普通Al-Mg合金要低。     

含微量Zr和Y的Al-Zn-Mg-Cu合金的组织与力学性能

采用光学显微镜、扫描电镜、X射线衍射和室温拉伸等检测技术研究了含微量锆和钇的Al-Zn-Mg-Cu合金的组织与力学性能。结果表明,在Al-Zn-Mg-Cu合金中复合添加微量(总量为0.35%)锆和钇,铸造组织中出现了Al3Y初生化合物,晶粒细小均匀。合金组织的再结晶被强烈抑制,再结晶组织的体积分数较小,晶粒被细化,合金的强度较单独添加锆或钇显著提高。但由于钇的加入使得基体中残留的较粗大化合物(S相)增多,导致合金的延伸率明显下降。     

钪对AZ91合金组织和性能的影响

研究钪在AZ91合金中的相组成、形貌及其对合金组织和性能的影响。结果表明,钪在合金中生成Al3Sc高温耐热相,细化了枝晶组织。钪添加量为0.6%时,室温和200℃的抗拉强度分别为265.4MPa和161.1MPa。钪可显著降低合金自腐蚀电流密度,但腐蚀电位只有轻微增加。     

镱对铝-镁合金显微组织和力学性能的影响

研究了Yb对Al-Mg合金显微组织和力学性能的影响.结果表明:添加0.3%(质量分数)Yb降低了Al-Mg合金的抗拉强度和屈服强度,主要是由于含Mg和Yb的化合物相的形成降低了Mg和Yb在Al基体中的固溶度,从而减小固溶强化效果.但添加1.0%Yb,基体中Yb溶质原子的浓度提高,产生很强的固溶强化效果,并提高热挤压制品的位错密度和加工硬化程度,改善合金的屈服强度和抗拉强度.     

电解生产Al-Sc-Zr多元合金的方法

中国专利CN151403A本发明涉及一种电解生产Al-Sc-Zr多元合金的方法。这是一种以铝、钪和锆的氧化物为原料,采用电解法将铝、钪和锆同时电解析出形成合金,直接生产Al-Sc-Zr多元合金的方法。其工艺条件是控制电解质熔融冰晶石体系的重量百分比成分,即:Al2O3 1%～6%、     

复合添加Sc对Al-6.2Zn-2.5Mg合金板材焊接性能与组织的影响

文章利用显微硬度试验、显微组织观察等手段,研究了复合添加Sc元素对Al-6.2Zn-2.5Mg合金板材氩弧焊焊接性能与组织的影响规律。试验结果表明,带余高的含钪合金板材较不含钪的合金板材焊接系数提高了9.2%,具有较好的焊接性能;合金板材焊接接头中心处硬度值最低,并沿中心往基材方向,呈先升高后降低再增高的趋势,且硬度以焊缝为中心呈近似对称;且含钪合金板材的接头晶粒组织较不含钪合金板材的组织要细小得多。在焊接过程中,含Sc合金板材组织中形成的Al3Sc粒子提高了合金板材的整体焊接性能。     

电感耦合等离子体原子发射光谱法测定铝镁锰钪锆合金导线中的镁锰钪锆含量

建立了电感耦合等离子体原子发射光谱法快速测定铝镁锰钪锆合金导线中的镁锰钪锆含量的方法。采用30 mL盐酸(1+1)加1滴氢氟酸快速消解铝钪锆镁锰合金样品,通过铝基体匹配法消除基体的干扰,通过共存元素干扰试验确定了各元素测定谱线。方法中各元素校准曲线回归方程的线性相关系数均大于0.999 5,测得各元素的方法检出限为0.000 17%～0.000 55%,测定下限为0.001 7%～0.005 5%,相对标准偏差(RSD)为1.21%～4.72%,通过加标回收试验测得各元素的回收率为98.33%～102.86%,能满足科研和生产快速检测的需求。     

铝镁钪合金铸锭均匀化过程中的析出特性

采用半连续铸造制备了成分为Al-6Mg-0.4Mn-0.4(Sc-Zr),规格为300mm×1000mm的铝镁钪合金扁锭,研究了均匀化处理对铸态合金硬度、电导率和显微组织的影响。结果表明,铸态合金在均匀化处理过程中,350℃以下均匀化,合金硬度随退火温度升高而升高;350℃以上均匀化,合金硬度和硬度峰值随退火温度上升而降低,电导率则随退火温度的升高和保温时间的延长而单调上升。铸态合金均匀化处理过程中有类似于传统铝合金固溶时效过程中的析出特性,析出相主要为Al3(Sc,Zr),还有少量Al6Mn相粒子。硬度变化是半连续铸锭过程形成的含钪锆过饱和固溶体发生分解析出Al3(Sc,Zr)粒子所致。同时,含钪锆过饱和固溶体的分解析出导致基体固溶度的贫化,降低了合金的电子散射能力,合金的电导率升高。研究合金铸锭均匀化处理过程中Al3(Sc,Zr)粒子的最佳析出工艺为:300~350℃,6~8h。     

Er对Al-Mg合金显微组织和力学性能的影响

以纯度为99.7%的工业纯铝、99.9%的工业纯镁和Al-10%Er的中间合金为原料,采用铸锭冶金法制备3种不同名义成分的目标合金,研究稀土元素Er对Al-Mg合金显微组织及力学性能的影响。结果表明：Er明显地降低了合金的屈服强度、抗拉强度和伸长率。当Er的添加量（质量分数）为0.4%和1%时挤压态Al-Mg合金的抗拉强度（σb）分别下降82 MPa和40 MPa,屈服强度（σ0.2）分别下降13 MPa和11 MPa,伸长率（δ）分别下降11.3%和4.5%。显微组织分析表明,添加Er在基体中形成粗大的含Er和Mg的结晶相导致Mg在铝基体中的固溶度下降,从而减少了溶质原子与位错的交互作用,导致合金的屈服强度降低。在变形过程中,粗大的含Er和Mg的结晶相由于应力集中在较低的应力下发生断裂而形成微裂纹,微裂纹以较快的速率扩展至基体晶界,形成一种典型的韧脆混合断裂,使合金的抗拉强度和伸长率减小。     

锆和稀土元素细化Al-Mg合金铸态组织的机理探讨

采用金相显微镜、扫描电镜和能谱分析等手段研究了在Al-Mg合金中同时添加等量的稀土元素(La,Er)和Zr后合金的铸态组织,发现枝晶网胞尺寸明显减小,晶粒细化,同时有细小的Al3Zr粒子分布于晶内,而Al-RE化合物集中分布于晶界处.存在两种细化机制,生成的Al3Zr质点在凝固过程中起非均质形核的作用,稀土加入引起凝固过程中溶质再分配造成固液界面前沿成分过冷度增大.     

水解法分离钪钛锆的试验研究

采用水解沉淀法从钪的反萃富集物产品中分离钪钛锆,可实现钪与绝大部分钛、锆的分离。研究发现以硫酸铵作为改性剂,可明显改善水解溶液的过滤性能。在硫酸铵用量为0.7 g/100 mL,溶液pH值为1.0,水解温度100℃,水解时间1.5 h的优化试验条件下,钛、锆的去除率可达99.56%、99.80%,钪回收率可达86.57%,成功的实现了钪与钛锆的分离,为制备高纯氧化钪创造了有利条件。     

Microstructure and impression creep of age hardenable AA2219 aluminium alloy modified by Sc, Mg and Zr additions

The present work pertains to impression creep of age hardenable AA2219 Aluminium-copper (6.3%) alloy correlated with microstructure with the addition of scandium, magnesium and zirconium. These additions were systematically varied by preparing alloys of different composition using gas tungsten arc melting. Impression creep technique was used to study the high temperature stability of the alloys. Modified compositions of the alloy resulted in fine equiaxed grains, refined eutectics, large number of high temperature stable and fine precipitates. Among all the compositions, 0.8%Sc+0.45%Mg+0.2 %Zr addition was found to be significant in improving the high temperature stability of AA2219 alloy. From the calculated values of stress exponent (n) and activation energy (Q), mechanisms of dislocation-climb and glide interaction with the precipitate particle are proposed.     

微量钪(Sc)对5A01合金性能与显微组织的影响

研究了在5A01合金基础上添加0．2％Sc和0．3％Sc后合金的显微组织、力学性能、腐蚀性能及焊接性能。结果表明，微量Sc的加入，初生Al3Sc或Al3（Sc，Zr）粒子可成为有效的非均质晶核，大大地细化合金的铸态晶粒，次生Al3Sc或Al3（Sc，Zr）粒子，能有效地钉轧位错和亚晶界，稳定亚结构并强烈抑制合金的再结晶。因此，加入Sc后的试验合金基体及焊接强度提高，腐蚀性能和焊接性能与5A01合金相当甚至更好。     

Evolution of the structure and phase composition of rapidly solidified Al-Mg-Mn-Sc-Zr alloys during deformation in a bridgman anvil

Metallography and electron microscopy are used to study the formation of submicrocrystalline and nano-structured states in Al-Mg-Mn alloys with scandium and zirconium during shear at a high hydrostatic pressure. The evolution of the structure and changes in the hardness of the alloys are discussed in relation to their composition and casting and heat treatment conditions.     

以机械合金化新工艺制造弥散强化铝镁合金

把纯铝粉和铝-镁合金粉与炭黑或有机试剂（如甲醇、硬脂酸等）在高能球磨机内研磨,获得机械合金化粉末。将这种粉末冷等静压密实,然后在820°K下挤压,挤压比为26:1,最后制得合金棒材。这种棒材的机械性能检验结果表明,用机械合金化新工艺制造的弥散强化铝-镁合金,机械性能优良。例如54号合金,其机械性能是,σ_b519—529MN/m2,σ_0.2510—519MN/m2,δ4—6%,Ψ9-14%。实验结果还表明,采用这种新工艺制造的铝-镁合金,与铸造铝-镁合金相比,它的机械性能有很大的改善和提高。特别是在573°K温度下经100小时退火后,其极限抗张强度下降得很小或完全不下降。因此这类合金作为一种结构材料使用将会有很大的潜力。     

Structure and mechanical properties of ingots and rolled sections of aluminum alloy based on the Al-Mg-Mn system

Commercial ingots and hot-pressed rolled sections of Al-Mg-Mn alloy doped with zinc, scandium, zirconium, chromium, and vanadium have been studied using optical microscopy, thermal analysis, electron microscopy, and electron-probe microanalysis. The compositions of the phase constituents and aluminum matrix of the alloy are determined. The sensitivity of the alloy to the formation of complex intermetallic compounds during solidification is revealed. The mechanical properties of ingots and rolled sections are determined.     

Investigation of Macrosegregation Formation in Aluminium DC Casting for Different Alloy Systems

Direct chill (DC) casting of aluminum involves alloys employing different solute elements. In this article, a qualitative analysis and comparison of macrosegregation formation is presented for three different alloy systems: Al-Mg, Al-Zn and Al-Cu. For this purpose, a multiphase, multiscale solidification model based on a volume-averaging method accounting for shrinkage-induced flow, thermal-solutal convection and grain motion is used and applied to an industrial-scale DC-cast ingot. The primary difference between these alloys is the thermal-solutal convection with Al-Mg having a competing thermal and solutal convection, whereas the other two systems have a cooperating thermal and solutal convection. In the study, the combined effect of the macrosegregation mechanisms is analyzed for each alloy to assess the role of the alloy system on the final macrosegregation.

     

Fluidity and Hot Cracking Susceptibility of A356 Alloys with Sc Additions

A356 with scandium (Sc) addition provides interesting results beyond costs. For the practical use of Sc, the effects of Sc on castability must be considered. Fluidity and hot cracking are important factors defining the castability of aluminum casting alloys. In the present work, the influence of Sc addition on the castability of A356 hypoeutectic Al–Si alloy was investigated, which was evaluated through fluidity and hot cracking susceptibility. The fluidity of the alloys was studied by measuring the total volume of solidified aluminum in a multi-channel mold. The hot cracking susceptibility of the alloys was evaluated by using a constrained-rod casting mold test. The results of the fluidity and hot cracking susceptibility test were supported by microstructural analysis. The results indicate that 0.2 wt% Sc addition significantly increases the fluidity of A356 alloy, due to the grain refinement and eutectic Si modification by changing the solidification mode. However, the fluidity slightly decreases when the Sc content increases to 0.4 wt% due to the formation of primary Al₂Si₂Sc intermetallic phase. The hot cracking of A356 alloy was completely diminished when Sc was added to the alloy.