"绿色”高效Al -Si合金变质剂--Al-P中间合金

为了解决Al-Si变质过程中的环境污染问题,用熔铸法制备了一种高效,低价格且适于产业化生产的Al-Si合金变质剂－Al-P中间合金,该中间合金w(P)可达到2．0％－5．5％,对共晶和过共晶（含Si量12％－24％）成分的Al-Si合金进行变质,加入0．3％－0．8％的Al-3P中间合金即得良好的变质效果,使其初晶Si数量明显增多,平均晶粒尺寸分别下降到30μm和50μm以下,该中间合金使用工艺简便,可在低温下加,而且无污染,无反应渣,变质效果长效稳定,易储存、使用综合成低,克服了当前变质的缺点,可以实现Al-Si合金的“绿色”变质,有着广阔的应用前景。     

稀土及锶对铸造铝硅合金的协同变质作用EI

本文介绍了稀土和锶对ZL102及ZL104两种合金的协同变质作用。这两种铝硅合金只用稀土变质在砂型铸造时,其金相组织和力学性能与未变质的相差不多;若仅用锶变质,两种合金砂型铸造试样针孔度在5级以上,均不能满足砂型铸造生产要求。在这两种合金中加入0.2％稀土及0.04％锶时,变质效果良好,针孔度也低。     

Sr-Y复合变质对Al-7Si合金组织和性能的影响

为降低锶(Sr)变质Al-7Si合金熔体的含氢量和解决单添加稀土钇(Y)导致合金生产成本上升的问题,利用测氢仪、光学显微镜(OM)、扫描电镜(SEM)、WDW电子万能试验机和导电仪等测试手段,研究了 Sr-Y复合变质对Al-7Si合金微观组织和力学性能的影响规律并对其作用机制进行了分析探讨.结果表明,Sr-Y复合变质不仅能降低合金熔体含氢量,还具有细化α-Al相和变质共晶Si的作用,同时能够提高合金力学性能和导电率.当添加0.05％Sr+0.15％Y复合变质剂时,熔体含氢量仅为0.12 mL/(100g Al),合金α-Al相高度细化为致密的等轴晶或椭圆晶,共晶Si从粗大的板片状和纤维状转变为细小的颗粒状.T6热处理后的合金抗拉强度、延伸率和导电率达到了 296 MPa、10.2％和41.7％IACS,比单独Sr变质分别提高了 10％、21％和7％,其拉伸断口表面呈现大量细小密集的韧窝,形状规则且分布均匀,属于韧性断裂.     

稀土及锶对铸造铝硅合金的协同变质作用

本文介绍了稀土和锶对ZL102及ZL104两种合金的协同变质作用。这两种铝硅合金只用稀土变质在砂型铸造时,其金相组织和力学性能与未变质的相差不多;若仅用锶变质,两种合金砂型铸造试样针孔度在5级以上,均不能满足砂型铸造生产要求。在这两种合金中加入0.2％稀土及0.04％锶时,变质效果良好,针孔度也低。     

Mg-4Sr中间合金的微观组织及其在AZ91D镁合金中的组织遗传效应研究

采用"对掺法"制备了相同成分、不同组织的Mg-4Sr中间合金。利用不同组织的Mg-4Sr中间合金在相同工艺条件下对AZ91D镁合金进行变质处理,对比分析了不同组织的Mg-4Sr中间合金试样的变质效果。实验测定了Mg-4Sr中间合金的DSC曲线,分析了Mg-4Sr中间合金的熔化特征。结果表明,Mg-4Sr中间合金由α-Mg基体和Mg17Sr2相构成。Mg-4Sr中间合金在AZ91D镁合金中存在组织遗传效应,组织细小均匀的Mg-4Sr中间合金对AZ91D镁合金表现出较好的变质效果。相同成分、不同组织的Mg-4Sr中间合金具有不同的DSC曲线,组织细小的Mg-4Sr中间合金的初始熔化温度和熔化焓都较低,从而导致其变质效果的差异。     

Al-10Ce中间合金对α-铝变质的研究

用X射线衍射、光学显微镜、扫描电镜和能谱等分析Al-10Ce中间合金的相组成和微观形貌,研究Al-10Ce中间合金对α-铝的变质处理效果及对α-铝的长效性变质和重熔稳定性变质,并与钠盐变质进行了对比.结果表明:Al-10Ce中间合金用量对变质效果的影响很大,Al10Ce中间合金用量为0.30%左右时达到最佳变质效果,用量少变质效果差,用量过多则形成过变质.用Al-10Ce中间合金对α-铝进行变质,可取得极好的变质效果,变质持续时间比钠盐变质剂更长久且具有更好的重熔稳定性.     

铝硅合金变质处理及去除超标镁锌的研究

系统研究了锶盐及其复合变质剂对铝硅合金的变质效果,以及几种处理方法对铝合金中杂质元素镁、锌的影响规律。所得主要结果是:锶盐可以使铝硅合金的硅相由针杆状变为长度尺寸在100μm以下的短杆状或弯曲的纤维状。锶盐变质剂存在着与锶变质相同的变质潜伏期现象,将锶盐与钠盐或磷盐复合变质能够消除这种现象。所研究的变质剂加入量小,提高合金的力学性能和使用性能;真空蒸发处理能够有效地降低铝合佥中的杂质锌量,向铝合金中吹入氟利昂与氮气的混合气体或加入六氯乙烷熔剂都能够有放地降低铝合金中的杂质镁量,根据铝合金的含镁量确定氟利昂的吹入量或六氮乙烷的加入量。     

Co对Al-5％Fe合金铸态组织的影响

研究了Co对Al-5％Fe(质量分数，下同)合金中Al3Fe相形貌的改善作用。合金中加入Co后可以在很大程度上改善Al3Fe相的形貌：未加Co的Al-5％Fe合金中的Al3Fe相大多为粗大的针状和片状；Co的加入量为O．2％时，Al3Fe相的形貌为小花朵状和细小条状；Co的加入量在0．2％～1．0％时，细化效果较好，但尤以0．2％为最好，Co的加入量超过1．0％后，Al3Fe相开始略微粗化。在对Co元素的面扫描时发现其大多固溶在Al3Fe相内。X衍射分析发现，Co的量为0．2％和1．0％时合金中只存在Al和Al3Fe相，并未发现其它相。     

细化、变质剂Al-Ti-C-Sr中间合金的制备及效果研究

采用二步法制备Al-Ti-C-Sr中间合金,预制AI-10Sr铝熔体温度850℃,用纯氩气精炼。采用自蔓延法预制Al-Ti-C铝液,氟钛酸钾和石墨粉加入熔体的温度为800℃-900℃,并在最终使熔体达到1200℃以上。合成Al-Ti-C-Sr中间合金是在Al-Ti-C熔体温度在800℃-900℃时加入AI-10Sr合金。再用制备好的Al-Ti-C-Sr中间合金对A356铝合金进行细化变质处理,具有细化和变质双重作用,效果明显。     

Sr对6063铝合金组织和性能的影响北大核心CSCD

通过电磁感应炉制备了含锶6063铝合金,对制备的试样采用光学显微镜(OM)、X射线衍射(XRD)、硬度测试、拉伸测试研究Sr含量对6063铝合金组织和性能的影响。结果表明:Sr元素的加入可以细化合金的铸态组织,改变组织形貌。当Sr含量为0.20%时,细化效果最好,合金其力学性能最优。随着Sr含量的增加,6063铝合金出现新相Al4Sr,随着组织中Al4Sr相增多,Mg2Si相的析出减少,减弱了对合金的强化效果,合金的力学性能呈下降趋势。     

Influence of boron on the microstructure and mechanical properties of Al-11.6Si-0.4Mg casting alloy modified with strontium

Abstract

The influence of the addition of Al-1B master alloy on the microstructure and mechanical properties of Al-11.6%Si-0.4%Mg alloy modified with 0.030%Sr has been investigated. The mechanical properties and fracture behaviour of the alloys as cast and after T6 heat treatment with three different melt treatments (no treatment; 0.030%Sr modifying treatment; and 0.030%Sr + 0.028%B combined melt treatment) were also compared. Al-1B master alloy has a strong action in refining the dendritic structure in near eutectic Al-Si casting alloys modified with Sr. The Sr+B combined melt treatment can improve considerably the mechanical properties of the alloys, both as cast and after T6 heat treatment. Fracture modes of the alloys with the Sr modifying treatment and the Sr+B combined melt treatment are typically ductile. However, fractographs indicate that the alloy with combined melt treatment suffered greater ductile deformation before fracture. The Sr+B combined melt treatment significantly improves the mechanical properties of near eutectic Al-Si casting alloys.     

Role of C and Fe in Grain Refinement of an AZ63B Magnesium Alloy by Al-C Master Alloy

1. IntroductionMagnesium alloys have been utilized as structural ma-terial replacing other metals and plastics in the electronicand automobile industries because of their light weightand high recyclability. Grain refinement[1~9] is an im-portant method to improve their mechanical propertiesand workability.Mg-Al based alloys are the most common commer-cial magnesium alloys, and grain-refining treatment isgenerally required. Carbon addition[10~17] and Elfinalprocess[18~22] are the two major gra…     

抗Zr“中毒”Al-Ti-B-C中间合金对7050铝合金力学性能的影响

通过场发射扫描电子显微镜(FESEM),X射线衍射仪(XRD),能量色谱仪(EDS)分析Al-5Ti-1B,Al-4Ti-1C和Al-5Ti-0.8B-0.2C中间合金的微观组织与物相组成,比较研究3种中间合金对7050铝合金晶粒尺寸与力学性能的影响。结果表明:Zr的存在削弱了Al-5Ti-1B和Al-4Ti-1C中间合金的细化效果,而对Al-5Ti-0.8B-0.2C中间合金细化效果影响较小。含掺杂型TiC粒子的Al-5Ti-0.8B-0.2C中间合金具有较好的抗Zr"中毒"能力,加入量为0.2%(质量分数,下同)时,含Zr7050铝合金平均晶粒尺寸由200μm细化至(60±5)μm,室温极限抗拉强度由405MPa提高到515MPa,提高了27.2%,伸长率由2.1%提高到4.1%。而加入0.2%的Al-5Ti-1B或Al-4Ti-1C中间合金时晶粒尺寸较粗大且分布不均匀,表现出明显的细化"中毒"。     

Influences of Preparation Conditions and Melt Treatment Procedureson Melt Treatment Performance of Al-5Ti-Band Al-10Sr Master Alloys

The influences of preparation conditions of Al-5Ti-B （as-cast and hot-rolled） and Al-10Sr （as-cast and hotextruded） and melt treatment procedures on the grain refinement and modification performance of A356 alloy are experimentally studied. For the two master alloys, the 50% reduction is sufficient to meet the demands of the efficient grain refinement and modification of A356 alloy. When Al-STi-B is introduced into the melt prior to degassing, the grain refinement efficiency of Al-5Ti-B will be greatly increased due to the better dispersity of TiB2 particles. Al-5Ti-B master alloy is less prone to affect the modification effect of Al-10Sr when they are used together.     

Effect of 0.1% vanadium addition on precipitation behavior and mechanical properties of Al-6063 commercial alloy

The effect of 0.1 wt% vanadium additions on the precipitation behavior and the mechanical properties of a commercial Al-6063 alloy were studied. A master alloy containing 3 wt% V was added during casting. The cast ingot was homogenized, extruded and cooled employing two different cooling modes: forced air and water. Further aging was carried out following the standard T5 and T6 treatments for alloys with and without vanadium. The microstructural characterization, mechanical properties, and fractografic study were carried out. The addition of 0.1% vanadium to Al-6063 alloy under T5 treatment, accelerates the precipitation kinetics of β″ and β′ phases. The alloys with and without vanadium under T6 show a similar behavior, the co-existence of β′ and β″ precipitation is observed in both alloys. In general, vanadium additions to Al 6063 have a detrimental effect on the mechanical properties, showing only a beneficial effect for certain specific conditions.     

等轴晶移动条件下金属凝固温度场、流场及溶质分布数值模拟

本文利用作者提出的固相移动条件下金属凝固传热、传质及动量传输数学模型对砂型铸造 Al-4.5%Cu 合金铸锭凝固过程进行了数值模拟研究与试验验证。模拟冷却曲线及宏观偏析与试验结果基本相符。     

Al-5Ti-0.25C细化剂对2024铝合金组织及力学性能的影响

研究了Al-5Ti-0.25C细化剂对2024铝合金铸态显微组织及力学性能的影响。试验结果表明:未添加细化剂时,2024铝合金显微组织呈粗大的枝晶状,平均尺寸约为150μm;添加Al-5Ti-0.25C后,晶粒为细小的等轴晶。本试验条件下,最佳的细化剂添加量为0.3%,此时,2024铝合金的平均晶粒尺寸为56μm,其力学性能得到显著提高,抗拉强度和延伸率分别为382 MPa、2.60%,与未细化试样相比增幅分别为12.4%、69.9%。     

Effect of Al-5Ti-1B on the microstructure of near-eutectic Al-13.0%Si alloys modified with Sr

The addition of Sr in Al-Si alloys as a modifier causes a transition of the morphology of eutectic silicon from coarse plate-like or acicular to fine fibrous. However, it may also lead to the formation of long columnar dendritic -Al phase. Al-5Ti-1B master alloy is often used as a grain refiner to achieve the fine equaixed grains in aluminum and aluminum alloys. The aim of the present study is to highlight the effect of Al-5Ti-1B master alloy additions on the microstructure of near-eutectic Al-Si alloys modified with Sr. When the addition of Al-5Ti-1B master alloy was below 0.82 mass%, the dendritic -Al phase changed from long columnar to equiaxed, and there were no noticeable changes of the morphology and size of eutectic silicon, while the size of eutectic cells decreased slightly. However, when the addition was above 0.82 mass%, the deleterious influence of Al-5Ti-1B master alloy on the modification effect of Sr emerged and with further increases in addition level a fully unmodified microstructure was finally produced. The results indicate that the effective Sr in the melt decreases with increased addition of Al-5Ti-1B. The poisoning event of Al-5Ti-1B master alloy on the modification of Sr is supposed to be related with the interaction between Sr and Ti.     

线性电磁搅拌对K417高温合金母合金锭质量的影响

为了提高高温合金母合金锭的质量,本文提出了在高温合金真空熔铸过程中,施加线性电磁搅拌的真空电磁铸造新技术。使用电子探针和光学显微镜,研究了在真空熔铸的凝固过程,施加工频线性电磁搅拌对K417高温合金母合金锭质量的影响。实验结果表明:在K417高温合金真空熔铸的凝固过程中施加140A的工频线性电磁搅拌,能够细化高温合金母合金锭的等轴晶组织、增加高温合金母合金锭的断面等轴晶比例、大幅减轻枝晶偏析的程度并能将高温合金母合金锭的中心缩松缩孔比率从54%降低到35%,从而使高温合金母合金锭的质量得到明显改善。     

TiH2-based Ti-1Al-8V-5Fe PM alloys with different addition methods of alloying elements

The powder metallurgy high-strength Ti-1Al-8V-5Fe alloy (Ti-185 alloy) was investigated in this paper with different addition methods of alloying elements, Al, V, Fe pure elements powder (EP) or 1Al-8V-5Fe ternary master alloy powder (MAP), based on TiH₂ powders at the sintering temperature from 1150 to 1350°C. The results indicate that the Ti-185 alloy with the 1Al-8V-5Fe master alloy (Ti-185 MAP alloy) possesses the higher relative sintered density, less oxygen content, and less α-phase volume fraction versus the Ti-185 alloy with Al, V, and Fe pure elements (Ti-185 EP alloy). No matter where the sintering temperature is 1150, 1250, or 1350°C, Ti-185 MAP alloy invariably has the higher yield strength and hardness which have a strong relationship to its higher density and less volume fraction of softer α-phase in comparison with Ti-185 EP alloy.