大型铝合金汽车底盘一体化砂型铸造技术

针对大型铝合金汽车底盘铸件的结构特点，分析铸造工艺难点及要点，提出大型铝合金汽车底盘一体化砂型铸造技术，并进行合金熔体净化、合金晶粒组织细化、薄壁件完整充型、尺寸精度控制等方面的研究。研究结果表明，通过合金熔体净化、合金晶粒组织细化，可以获得本体各向同性、力学性能优异的大型铝合金汽车底盘铸件。通过一体化砂型铸造技术，获得充型完整、内部质量优良的大型铝合金汽车底盘铸件，达到设计要求。     

多孔铝合金的压缩吸能性能

在Al-Si合金基础上，加入合金元素采用渗流法制备了高比强度的新型多孔铝合金，研究了孔结构参数，固溶时效处理对新型多孔铝合金的压缩吸能性能的影响。结果表明，不同的孔结构参数以及固溶时效处理对多孔铝合金的压缩吸能性能有着显著的影响。     

AlTiB和AlTiBRe对铝合金晶粒细化的影响

研究了AlTiB和AlTiBRe中间合金细化剂对铝合金的细化效果和细化机理，实验发现AlTiBRe对ZL104合金的细化效果优于AlTiB，两种细化剂对Al—1．4Mg合金均有细化作用，但细化效果的区别并不明显。金相实验结果表明，当稀土含量合适时，AlTiBRe中的Re不但在铝合金熔体中起良好的除杂作用，提高了铝合金的合金化程度，而且可以细化枝晶组织。     

半固态ZnAl27合金组织形成机理研究

采用机械搅拌法制备了半固态ZnAl27合金，与常规铸造合金进行了对比，并对其组织形成机理进行了研究，为锌铝合金的半固态加工这一新技术提供了理论依据。     

特种车辆新型高强韧铝合金负重轮液态模锻工艺成型研究

在采用新型高强韧铝合金液态模锻成型特种车辆负重轮时,主要研究了新型铝合金液态模锻成型工艺和热处理工艺参数等对合金力学性能及组织的影响。试验表明,新型铝合金液态模锻工艺成型负重轮的组织明显优于其他合金,力学性能得到了显著提高。     

高强铝合金半固态精密成型技术应用研究

7000 系列高强铝合金已在航空、航天等领域得到广泛应用。但这类高强铝合金因合金元素含量高,存在凝固组织粗大且不均匀、合金元素偏析严重、铸件易开裂等问题,难以直接铸造成型。文中开展了7075 铝合金环缝式强电磁搅拌流变制浆及半固态精密成型技术的应用研究。研究表明,环缝式强电磁搅拌半固态精密成型技术有效提高了7075 铝合金成分均匀性,铸件组织细化,热裂倾向减少明显,合金的成型性能和零件的力学性能大幅提高,可以实现高强铝合金零件的近净成型。     

合金元素对铸造铝合金切削加工性的影响

随着铸造水平和加工水平的不断提高,铸造铝合金在摩托车、汽车、航空航天以及国防行业的应用日益广泛。铸造铝合金比重小、强度高、耐磨性和耐腐蚀性好,在汽车行业铸造铝合金产品实现了轻量化,而且性能方面较灰铸铁有明显提高。长期以来,铸造铝合金一直被看成是易加工材料。但在切削加工铸造铝合金过程中,严重的刀具粘附倾向和刀具磨损使得加工表面质量和尺寸精度很差。因而,改善铸造铝合金的切削加工性成了广大研究人员关注的问题。添加不同的合金元素使铸造铝合金表现出不同的金相组织、力学性能以及切削加工性能。影响铸造铝合金切削加工性的合金元素分为合金化元素、晶粒细化元素、变质元素、易切削元素以及杂质元素五类。本文综述添加合金元素将对铸造铝合金切削加工性能的影响,为进一步研究改善铸造铝合金的切削加工性提供研究思路。     

铸造铝合金RR350中镍相热强化机制的研究

通过对铸造铝合金RR350显微组织、分布状态、合金相特性及显微硬度的分析，研究了含镍合金相在使用过程中所起的不同强化机理及作用。试验表明：铸造铝合金经固溶时效后，会形成许多含镍合金相，并且随加热温度提高，硬度会有极值存在。RR350铸造铝合金中含镍相存在会提高热强性。     

熔体中氢含量对ZL114A合金冲击韧度的影响

通过测试铝合金熔体中的氢含量和合金的冲击韧度,分析材料显微组织和断口微观断裂特征,研究了铝合金熔体中氢含量对铸件冲击韧度的影响.结果表明:试验条件下合金中的气孔呈球形弥散分布,合金的冲击韧度随着氢含量的增多而增大.     

压铸技术及压铸合金的发展与应用

简述了压铸发展的历史及压铸技术的发展状况。叙述了压铸铝合金、镁合金、锌和锌铝合金的研究开发与应用状况,分析了压铸合金有待进一步研究开发的问题     

An experimental investigation of the effect of coatings and cutting parameters on the dry drilling performance of aluminium alloys

As a result of the need to automate assembly in the aircraft industry, along with economic and ecological reasons, industry and research institutions have been pushed to develop dry drilling for aluminium alloys to eliminate the need for cooling fluids. The main difficulties in dry drilling are accelerated tool wear due to workpiece material adhesion on the tool and the formation of bigger-sized burrs. This paper describes an experimental research study on machinability in the dry drilling of aluminium alloys and on the potential of the new design of tools and coatings. Dry drilling tests were performed using uncoated drills and two different coatings produced by means of an arc evaporation PVD process. Experiments consisted of machining with a 10-mm diameter three-edged drill to produce 25-mm deep holes. Tool wear evolution and burr size were analysed, as well as the impact of the process parameters on torque, power, feed force and tool temperature.     

汽车铝合金车身板材的研究现状及发展趋势

综述了国内外汽车铝合金2000、5000和6000系车身板的研究进程、应用现状及发展前景,指出了新型Al-Mg-Si基合合金今后汽车车身板研究应用的一个重点,它具有强度和塑性的良好组合,耐蚀性优良,易着色等优点,此外,还列出了汽车铝合金车身板研究应用中存在的成本高和成型性差等问题,提出了我国开发高性能且有特色的汽车铝合金车身板材的研究方向。     

铝合金及铝化物涂层发展现状

综合国内外铝合金及铝化物涂层的发展,较全面地介绍了涂层类型、制备方法及应用。重点突出新型铝合金及铝化物涂层及新型制备方法,指出用粉芯线材电弧喷涂以及电弧喷涂新技术制备铝舍金及铝化物涂层具有广阔的发展前景。     

Tribochemistry of aluminium and aluminium alloy systems lubricated with liquids containing alcohol or amine additive types and some other lubricants — a review

The ability of a lubricating oil to reduce wear and prevent damage of interacting solids is a crucial factor controlling lubricant formulation. It is well known that friction produces local high temperatures. Many chemical reactions that are initiated by the friction process itself occur at much lower temperatures than those needed to provide the activation energy. Under boundary lubrication conditions, a clean surface exposed as a result of mechanical activity of the solid surface is extremely reactive, especially in the case of metals. This review mostly relates to the tribochemistry of aluminium, and discusses the tribological characteristics of alcohol‐ and amine‐type liquids used as either additives or lubricants to lubricate aluminium and its alloys under boundary friction conditions. Although tribochemical reactions during sliding are perceived in various ways, here the emphasis is on the negative‐ion‐radical action mechanism (NIRAM) approach. This review addresses the question as to how present knowledge of tribochemistry can be applied to the elucidation of the mechanisms of action by which the boundary lubricant compounds considered reduce aluminium‐on‐aluminium, steel‐on‐aluminium, and aluminium‐on‐steel wear. Also, information and a discussion on the tribological behaviour of other additives and/or lubricants in relation to the friction and wear of aluminium and its alloys are presented. A concise review of the most recent work on the tribochemistry of selected fluorinated alcohols is also included.     

Preparation and characterization of spark-anodized Al-alloys: Physical, chemical and tribological properties

Aerospace applications and energy saving strategies in general boosted the interest and the research in the field of light weight materials, typically on alloys based on aluminium. Aluminium itself does not provide sufficient mechanical strength for structural parts, but there exists a lot of recently developed alloys containing silicon, copper, magnesium, zinc or manganese in various combinations and compositions exhibiting excellent mechanical properties. These alloys require surface treatments or coatings to withstand corrosive ambient conditions. Among those treatments known as chromate replacements, plasma oxidation processes were used for different applications, especially if the surfaces have to face mechanical load or severe environmental conditions. In this work, specimens of different aluminium alloys have been plasma oxidized by micro-arc treatment in silicate and phosphate solutions. The ceramic coatings were characterized with respect to phase composition, micro-hardness and corrosion stability. In addition, the tribological performance of the coatings was investigated using a ball-on-disc tribometer with reciprocating motion against sintered alumina ball. The typical worn surfaces of the Al substrate and the ceramic coatings were observed by a scanning electron microscope. Applying same wear conditions, the wear rates in different depth of the coatings are nearly similar. However, in a defined depth of the coatings, wear rate gradually decreases with wear duration. During friction process, a-stable transfer layer consisting of oxides was formed on the tribo-contact area of the coatings. The friction coefficient in a steady friction state is in the range of 0.8.     

挤压铸造汽车空压机铝连杆的研制与应用

对挤压铸造汽车空压机铝合金连杆进行了较全面的试验研究。包括挤压铸造工艺参数和模具结构参数的选择 ,连杆用铝合金材料的选配及性能试验 ,连杆的台架试验等 ;结果表明 ,挤压铸造铝合金连杆完全可替代钢质连杆。并获得了挤压铸造铝合金连杆的最佳生产工艺方案     

Effect of sodium octanoate on the tribocorrosion behaviour of 5052 aluminium alloy

ABSTRACT

The 5000 series aluminium alloys are commonly used in a marine application where it is exposed to environments containing the chloride ions, which cause corrosion of aluminium alloy. The situation becomes even worse when aluminium alloys, in some situations, may suffer from combined corrosion and wear actions. The present study has been carried out to investigate the effect of sodium octanoate as a corrosion inhibitor on the corrosive wear behaviour of aluminium alloy 5052 in 0.5?M NaCl solution as simulated seawater. The effects of electrochemical potentials on the corrosive wear performance are also discussed.     

Tribological behaviour of diamond coatings sliding against Al alloys

A low wear rate, combined with exceptional physical properties, makes diamond an ideal candidate for the machining of non-ferrous materials. It is particularly interesting for tooling aluminium and its alloys as it offers these soft materials clean cutting and lets the shavings slide on the tool surface.It results from studies dealing with the friction of diamond against aluminium, that the tribological behaviour of this pair is greatly influenced by the presence of oxides, more particularly Al₂O₃, on the counterface surface. It was therefore necessary to better understand the role of these oxides during the cutting process, the way they modify the nature of the contact, and their effects on transferred layer formation.The tribological behaviour of diamond coatings prepared by the combustion flame process, sliding against aluminium alloys under different environments (vacuum, oxygen and water vapour), at two applied normal loads is presented here; the modifications of both the coatings (formation of amorphous carbon) and the counterfaces (depth of the friction track), as well as the transferred layers (chemical composition, aspect) are specifically studied.The surface changes are revealed by scanning electron microscopy observations. Raman spectroscopy and energy dispersive spectroscopy analyses were realised to highlight the observed phenomena.     

Effect of process parameters on tensile strength of friction stir welding A356/C355 aluminium alloys joint

In the present investigation, A356/C355 aluminium alloys are welded by friction stir welding by controlling various welding parameters. A356 and C355 aluminium alloys materials have a set of mechanical and physical properties that are ideally suited for application in aerospace and automobile industries and not widely used because of its poor weldebility. To overcome this barrier, weldebility analysis of A356 and C355 aluminium alloys with high speed steel (Wc-Co) tool has been investgated. An attempt has been made to investigate the influence of the rotational speed of the tools, the axial force and welding speed on tensile strength of A356/C355 aluminium alloys joint. The experiments were conducted on a milling machine. The main focus of investigation is to determine good tensile strength. Response surface methodology (box Behnken design) is chosen to design the optimum welding parameters leading to maximum tensile strength. The result shows that axial force increases, tensile strength decreases. Whereas tool rotational speed and welding speed increase, tensile strength increases. Optimum values of axial force (3 /KN), tool rotational speed (900 RPM) and welding speed (75 mm/min.) during welding of A356/C355 aluminium alloys joint to maximize the tensile strength (Predicted 223.2 MPa) have been find out.     

铝合金型材与其在电子设备上的应用

从工业用铝合金型材的材料性能、应用特点出发，通过与普通钢件的机械性能、加工工艺进行比较，显示出铝合金型材自身的优越性，并举例说明了其在电子设备上的应用。