铸造锌铝合金的研究进展及其应用

回顾了锌铝合金的研究历史，并详述了锌铝合金的成分、显微组织与性能的关系，以及变质、晶粒细化、热处理和其它工艺对锌铝合金的性能和组织结构的影响，最后介绍了铸造锌铝合金的应用，并对锌铝合金的发展趋势作了展望。     

La和Y对细化后A356铝合金显微组织的影响

利用金相显微镜和扫描电子显微镜等设备研究了稀土金属La和Y对经AlTiB和AlSr细化后的A356铝合金α-Al枝晶和共晶Si相显微组织的影响及作用机理。研究表明,金属La和Y加入A356铝合金后以AlSiLa或AlSiY的形式存在于α-Al相晶界中。La和Y不仅对A356铝合金共晶硅相具有明显的变质效果,而且对α-Al晶粒有细化作用。其中Y变质共晶硅和细化α-Al晶粒的效果均优于La。     

铝合金车轮毂的熔炼与重力铸造工艺

<正>中国专利CN101758204A本发明涉及一种铝合金车轮毂的熔炼与重力铸造工艺,包括如下步骤:(1)将铝合金进行熔化,在熔化室温度达到740~760℃时,通过氮气将精炼剂吹入熔化室进行精炼;(2)在调质室内添加Al-Sr中间合金、混合稀土(Re)和Al-Zr中间合金,对铝合金熔液进行复合变质及细化处理,并向调质室内吹入氮气进行二次除气;(3)铝合金熔液进入使用室进行     

A356.2低压铸造铝合金车轮表面针孔原因分析

对针孔缺陷车轮样件进行金相组织、化学成分、扫描电镜等试验分析,找出造成车轮针孔缺陷的主要产生原因,并通过提高熔炼工艺水平、铸造工艺改进、低压铸造模具冷却设计、保温风管设计等技术手段来减少或者消除针孔缺陷。     

熔体处理工艺对6005A铝合金铸锭质量的影响

针对6005A铝合金铸锭的熔铸工艺,采用低倍组织分析、拉伸测试、金相分析等手段对不同熔体停留时间生产的铸锭进行分析,研究了熔体处理工艺对铝合金显微组织及力学性能的影响。结果表明:熔体停留时间对铸锭的晶粒尺寸、疏松等级、晶粒圆整度、力学性能均有不同程度的影响。当熔体停留时间≤5 h,铸锭晶粒尺寸随熔体停留时间的延长而缓慢增大,晶粒圆整度、力学性能等基本维持不变;当熔体停留时间超过5 h时,晶粒尺寸急剧增大,晶粒圆整度、力学性能等显著降低。熔炼过程中控制熔体停留时间≤5h,可降低由于熔体停留所带来的不利影响。     

A356．2铸造铝合金生产中采样状态和采样时机对Si偏析的影响

本文通过试验摸索,找出规律,论述了铸造铝合金生产中不同时间和状态下采样对Si偏析的影响,并应用于指导生产实际。     

A356铸造铝合金轮毂组织与性能分析

分析了 A356合金和经T6热处理的A356-T6合金的组织与性能,结果表明,A356-T6合金的整体抗拉强度几乎不受固溶时间的影响,且其屈服强度和抗拉强度显著提高,但随着固溶时间的增加,其伸长率逐渐降低.随着热处理时效从4增加至48 h,A356-T6合金的屈服强度增加了约183.25％,抗拉强度增加了约71％.通过...     

A356铝合金的强韧化工艺研究

研究了A356铝合金的组织结构特点及强韧化工艺控制,通过采取细化组织、硅相变质、微合金化处理及优化热处理工艺等措施和手段提高车轮用A356铝合金的强韧化效果.     

Porosity Prediction in A356 Wheel Casting

Metallurgical and Materials Transactions B - A FLUENT™-based thermal-fluid-compositional model has been developed and applied to a low-pressure, die-cast, A356 aluminum alloy wheel to explore...     

氮气在铝合金熔体净化处理中的应用

本文论述铝合金板锭内部气体的来源，氮气精炼的除气除渣原理及其在铝合金板锭生产中的实际应用。     

铝轮毂固溶热处理联合电炉的设计

介绍了铝轮毂固溶热处理联合电炉的设计方法、结构特点、炉子组成以及需要注意的问题。     

ZL205A铝合金熔体净化效果分析

介绍了铝熔体中夹杂物与气体的主要存在形态及其相互作用。结合生产应用实践．简述了ZL205A铝合金熔体的净化工艺及其影响因素，提出铝液的净化应以除渣为主．去气为辅。     

熔体冷却速度对稀土Y变质A356铝合金微观组织及拉伸性能的影响

对不同熔体冷却速度所制备稀土Y变质A356铝合金的显微组织及拉伸性能进行了研究。结果表明,随着熔体冷却速度的降低,初晶α-Al晶粒变得粗大且分布凌乱,其二次枝晶间距增大;共晶硅由颗粒状、纤维状转变为片状、针状;合金的拉伸性能显著下降,拉伸断口由韧性断裂向脆性断裂转变。稀土Y对熔体冷却速度较敏感,需在较大的熔体冷却速度下才能使共晶硅按变质形态生长。     

Modeling of Microporosity Size Distribution in Aluminum Alloy A356

Porosity is one of the most common defects to degrade the mechanical properties of aluminum alloys. Prediction of pore size, therefore, is critical to optimize the quality of castings. Moreover, to the design engineer, knowledge of the inherent pore population in a casting is essential to avoid potential fatigue failure of the component. In this work, the size distribution of the porosity was modeled based on the assumptions that the hydrogen pores are nucleated heterogeneously and that the nucleation site distribution is a Gaussian function of hydrogen supersaturation in the melt. The pore growth is simulated as a hydrogen-diffusion-controlled process, which is driven by the hydrogen concentration gradient at the pore liquid interface. Directionally solidified A356 (Al-7Si-0.3Mg) alloy castings were used to evaluate the predictive capability of the proposed model. The cast pore volume fraction and size distributions were measured using X-ray microtomography (XMT). Comparison of the experimental and simulation results showed that good agreement could be obtained in terms of both porosity fraction and size distribution. The model can effectively evaluate the effect of hydrogen content, heterogeneous pore nucleation population, cooling conditions, and degassing time on microporosity formation.     

A356.2铝合金铸造工艺的生产实践

目前,A356.2铝合金主流的生产工艺有人工搅拌+链式铸造和电磁搅拌+热顶铸造两种方式,通过对上述产品的取样,对比分析了化学成分、组织结构和物理性能等,得出电磁搅拌+热顶铸造工艺生产的产品质量在各个方面均优于人工搅拌+链式铸造生产工艺产品质量,是生产高质量A356.2铝合金产品的发展方向。     

铝合金传剑轮材料的应用研究

介绍了常用铝合金传剑轮材料的使用要求和性能特点,分析了铝合金传剑轮典型失效的原因。结果表明,高温退火热处理急剧降低铝合金强度,导致传剑轮用铝合金材料的过载能力偏低,是铝合金传剑轮失效的主要原因。     

Nucleation Catalysis in Aluminum Alloy A356 Using Nanoscale Inoculants

Different types of nanoparticles in aluminum (Al) alloy A356 nanocomposites were shown to catalyze nucleation of the primary Al phase. Nanoparticles of SiC β, TiC, Al₂O₃ α, and Al₂O₃ γ were added to and dispersed in the A356 matrix as nucleation catalysts using an ultrasonic mixing technique. Using the droplet emulsion technique (DET), undercoolings in the nanocomposites were shown to be significantly reduced compared to the reference A356. None of the nanocomposites had a population of highly undercooled droplets that were observed in the reference samples. Also, with the exception of the A356/Al₂O₃ α nanocomposite, all nanocomposites showed a reduction in undercooling necessary for the onset of primary Al nucleation. The observed nanocomposite undercoolings generally agreed with the undercooling necessary for free growth. The atomic structure of the particles showed an influence on nucleation potency as A356/Al₂O₃ γ nanocomposites had smaller undercoolings than A356/Al₂O₃ α nanocomposites. The nucleation catalysis illustrates the feasibility of, and basis for, grain refinement in metal matrix nanocomposites (MMNCs).