电工铝杆用高效排杂净化熔剂及其处理效果

探讨了电工铝杆用高效排杂净化熔剂及其处理效果。结果表明:熔剂组成对其净化效果具有重要影响;DJ-1熔剂是电工铝杆的一种高效排杂净化熔剂,当其与特定的过滤工艺配合时,净化效果显著,除杂率及气孔降低率分别可达83.6％和91.2％,并有效改善了杂、气存在形态,从而直接影响到材料的微观断裂过程,显著提高了铝材的力学性能,尤其是塑性。采用该熔剂净化后进行晶粒细化处理,可充分发挥细化处理效果,明显提高了电工铝杆性能,尤其在σb>120 MPa时,伸长率仍达12.2％(与常规处理相比,提高幅度达62.7％),电阻率也降低了0.93％。     

高效排杂熔剂净化处理电工圆铝杆的试验研究

探讨了高效排杂熔剂净化处理对电工圆铝杆的冶金质量与性能的影响作用及规律。结果表明，用高效排杂熔剂净化处理明显提高了电工圆铝杆的冶金质量，其除杂率及气孔降低率分别达73．5％和92．1％，削弱了冶金缺陷的有害作用，明显提高了电工圆铝杆的力学性能，并使其电阻率有所降低；高效排杂熔剂净化后进行晶粒细化处理，充分发挥了细化处理效果，与常规处理相比，在强度提高的同时，伸长率仍得到明显提高（幅度达62．7％），电阻率降低了0．93％。     

提高铝熔体净化效果的理论基础及途径

铝熔体中Al2O3夹杂与氢的行为及相互作用关系的实质，是改善和提高铝液净化效果的理论基础，对于铝液净化工艺的合理设计极为重要。从定关键入手进行了分析讨论，提出杂与气相互作用的“寄生机制”观点；同时针对目前净化方法主要从除气角度进行设计，忽视杂气相互关系及对净化效果的影响等现状，在杂气关系分析的基础上，突破传统净化思路的束缚，首次明确提出了“排杂是除气的基础，排杂为主、除气为辅”的铝液净化原则，据此研究开发出熔剂过渡净化方法及相应的高效排杂净化熔剂，并指出了提高铝熔体净化效果的技术途径。     

高效排杂熔剂对6063铝合金的净化效果试验

用环保高效排杂净化熔剂对6063铝合金进行净化处理,并用OM、DTA、XRD、SEM等探讨了该熔剂的净化效果及对提高该材料力学性能的作用.结果表明:采用XRJ-2熔剂在特定的过滤处理工艺条件下,其排杂净化效果显著,除杂率和气孔降低率分别达52.26%和86.05%.     

铝熔体高效净化的理论及净化处理技术的现状分析

在杂气关系分析的基础上,提出"排杂是除气的基础,排杂为主,除气为辅"的铝液净化原则,根据此研究开发出熔剂过滤净化方法及相应的高效排杂净化熔剂,分析讨论国内、国外净化处理技术的发展现状及存在问题,提出提高铝熔体净化效果的技术途径.     

熔炼温度与静置时间对A356铝合金净化效果的影响

在对比不同熔剂对A356铝合金净化效果的基础上,研究了熔炼温度与保温静置时间对净化效果的影响。结果表明,排杂熔剂具有较好的除气除杂效果,随着净化处理温度的升高,排杂熔剂净化处理后的铝合金含杂量与含气量变化比较平稳,保持在一个较低水平;随着保温静置时间的延长,铝液中的含杂含气量保持比较稳定。     

铝熔体用稀土熔剂的使用效果及分析

针对我国在铝加工业存在能耗大，环境污染严重和含氢、含杂量高的问题，研究了一种新型溶剂JDN－I。结果发现，该熔剂个有多种功能：覆盖隔热作用，既可保护铝合金免潮湿大气的污染，又能细化晶粒，又可使共晶硅变质；铝熔体的含氢、含杂量降低到极低的水平，确保铝熔体的纯净化；细化变质作用，既可细化晶粒，又可使共晶硅变质；使用简便，不污染环境，在这种熔剂的作用，可使A356铝合金的流动性大大提高，并使抗拉强度度提高7．25％，伸长率提高85．58％。     

净化熔剂对A356铝合金处理效果的环境负荷评估

在不同净化熔剂对A356铝合金处理试验的基础上,主要从净化效果(含杂量、力学性能、铝净得率、渣中铝含量)、对环境的污染程度(有害气体排放量)以及熔剂价格等指标的考察,根据权重系数比例和影响幅度进行环境负荷的比较评估。结果表明,与常规熔剂处理相比,高效排杂净化熔剂RJ2及其处理工艺(B1)在各项评估指标(铝净得率、渣中铝含量、废弃物排放、熔剂价格等)的环境影响因子上均显示出最小值,其有害气体排放量不仅低于常规工艺,也明显小于相应国家标准限值,说明熔剂RJ2不含有对环境和人体有害的物质。定量计算表明:仅考虑有害气体排放程度(定性)时,最佳工艺(B1)的总环境影响因子仅为1.20,且各评估指标中环境负荷均为最小;将有害气体排放程度的试验数据量化,并将其计入总环境影响因子后,常规工艺的总环境影响因子达4.13,而最佳工艺(B1)的总环境影响因子仅为2.07,即环境负荷最小。     

铝熔体中夹杂物和气体的行为

分析了铝熔体中夹杂物和气体的行为，提出了寄生机制，并通过对废争化的研究加以论证，认为气寄生于杂，杂吸附着气，除气必排杂，排杂是除气的基础；采用熔剂过滤净化技术效果显著，应予重视。     

新型熔剂YQX-I对锌熔体组织和性能的影响

针对热镀锌熔体存在的问题,研究了一种新型熔剂YQX-I,用于纯锌熔体的覆盖保护和净化.实验结果表明,YQX-I熔剂使纯锌熔体在480℃时的烧损率从11.05％下降到3.56％,可使组织中夹杂变质细化,可使纯锌抗拉强度提高0.7％,伸长率提高31.6％.     

Composite purification technology and mechanism of recycled aluminum alloys

Iron-rich inclusions in aluminum alloys can be effectively removed by composite purification of sedimentation and filtration technology. The results show that the purposed method has no negative effects on aluminum alloys and obviously improve their mechanical properties.     

A356铝熔体的复合过滤试验研究

提出一种CCFF（Composite Ceramic Foam Filter，复合陶瓷泡沫过滤器）过滤净化模型，通过对A356废铝进行试验，除杂效果良好。对熔剂的涂覆方式和CCFF中的试验现象进行了分析。通过解释模型的机理，证明模型具有可用性。     

The electromagnetic filtration of molten aluminum using an induced-current separator

The production of clean metal, free from oxides and other types of nonmetallic inclusions, is central to product quality and performance. Toward this end, electromagnetic filtration is an emerging technology for the purification of molten metals. This paper reviews the theory and the mechanism of the electromagnetic separation of inclusions from molten metal and describes the induced-current electromagnetic separator developed at the University of Alabama. The results of laboratory and large-scale experiments on the purification of molten aluminum demonstrate the capability of the system for producing super clean metals.     

选择性沉淀法从钨酸盐溶液中除钼的工业试验

对“选择性沉淀法从钨酸盐溶液中除钼”新工艺进行了工业试验。结果表明对处理含WO3130～244g/L,含钼0.535～2.55g/L的工业钨酸铵溶液,除钼后净液中Mo/WO3达到2.00×10     

Mechanism of removing inclusions from molten aluminum by stirring active molten flux

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Wetting behavior and reaction mechanism of non-corrosive flux on aluminum

The energy-dispersive spectroscopy (EDS), X-ray diffraction analysis (XRD) and differential thermal analysis (DTA) were used to analyze the melting, spreading process, and reaction mechanism of non-corrosive flux on the surface of aluminum. The result indicates that the whole process can be divided into three stages. In the first stage, flux is heated from room temperature to its melting point, which is called the endothermic stage, mainly absorbs heat and generates a small amount of liquid flux. When the temperature exceeds the melting point of flux, a large amount of liquid flux is generated and reacts with oxide films on the surface of aluminum. This stage is called the reaction stage. The third stage is a spreading and cleaning process, in which residues and reaction products quickly flow out from the center with liquid flux. The different compositions of flux perform different functions in brazing. K₃AlF₆ can remove oxide film as a cleaner. Only in liquid or molten state can flux remove oxide film on the substrate.     

一种Al-Zn-Mg合金板材焊缝裂纹的原因分析及预防措施

Al-Zn-Mg合金板材在使用加工中焊接时焊缝处出现裂纹,分析了裂纹产生的原因,确认裂纹缺陷是因铸锭内部组织中存在粗大金属化合物聚集,该粗大化合物在板材轧制变形过程中产生分层所致.并从合金的元素含量、熔铸温度、搅拌方式、在线过滤等方面提出了避免该类缺陷的措施.     

Purification of niobium by multiple electron beam melting for superconducting RF cavities

In this work, purification of commercial grade (∼99.9 %) niobium by multiple Electron Beam Melting (EBM) is reported. Impurity removal of carbon, oxygen, nitrogen, aluminum, iron, molybdenum, zirconium and tungsten in niobium matrix is presented as a part of the ingot melting stages. The minor material loss of niobium during melting is attributed to the amount of decarburization based on the ratio of initial and critical content of oxygen to carbon. The analysis of nearly 60 impurity elements in niobium was carried out by glow discharge mass spectrometry. In the end, the purity of niobium after multiple electron beam meltings was found to be 4N while the purity enhanced from 99.9 % (3N) to 99.993 % (4N3), including gaseous impurities, and 99.98 % (3N8) to 99.998 % (4N8) without gaseous impurities. The glow discharge mass spectrometry analytical results of purified niobium indicated that the material is suitable as input material for further processing of fabricated superconducting radio-frequency cavities.