Microstructure and mechanical properties of A356 aluminum alloy wheels prepared by thixo-forging combined with a low superheat casting process

The A356 aluminum alloy wheels were prepared by thixo-forging combined with a low superheat casting process. The as-cast microstructure, microstructure evolution during reheating and the mechanical properties of the thixo-forged A356 aluminum alloy wheels were investigated. The results show that the A356 aluminum alloy billet with fine, uniform and non-dendritic grains can be obtained when the melt is cast at 635 ℃. When the billet is reheated at 600 ℃ for 60 min, the non-dendritic grains are changed into spherical ones and the billet can be easily thixo-forged into wheels. The tensile strength and elongation of thixo-forged wheels with T6 heat treatment are 327.6 MPa and 7.8%, respectively, which are higher than those of a cast wheel. It is suggested that the thixo-forging combined with the low superheat casting process is an effective technique to produce aluminum alloy wheels with high mechanical properties.

Production of A356 aluminum alloy wheels by thixo-forging combined with a low superheat casting process

The A356 aluminum alloy wheels were produced by thixo-forging combined with a low superheat casting process. The as-cast microstructure, microstructure evolution during reheating and the mechanical properties of thixo-forged wheels made from the A356 aluminum alloy were studied. The results show that the A356 aluminum alloy round billet with fine, uniform and non-dendritic grains can be obtained when the melt is cast at 635 ℃ When the round billet is reheated at 600 ℃ for 60 min, the non-dendritic grains are changed into spherical ones and the round billet can be easily thixo-forged into wheels. The tensile strength, yield strength and elongation of the thixo-forged wheels with T6 heat treatment are 327.6 MPa, 228.3 MPa and 7.8%, respectively, which are higher than those of a cast wheel. It is suggested that the thixo-forging combined with the low superheat casting process is an effective technique to produce aluminum alloy wheels with high mechanical properties.

Effects of melt spinning process parameters and wheel surface quality on production of 6060 aluminum alloy powders and ribbons

The aim of this study is to investigate the surface quality of the melt spinning wheel, which was changed from smooth type to textured structure, to atomize liquid metal to form powders. The effects of melt spinning process parameters like wheel speed, gas ejection pressure, molten metal temperature, nozzle–wheel gap and wheel surface quality on the morphological and microstructural features of 6060 aluminum alloy powders and ribbons were investigated. It was observed that ribbon type material was obtained with the smooth wheel and the powder was produced with textured type. The sizes of produced ribbons with smooth surface wheel varied in the range of 30-170 μm in thickness, 4-8 mm in width, and 0.5-1 m in length. The average powder size of the powders manufactured using the textured wheel was in the range of 161-274 μm, depending on the process parameters.Increasing the wheel speed, melt temperature and decreasing gas ejection pressure, nozzle-wheel gap resulted in the decrease of both ribbon thickness and powder size. The microstructures of the powders and ribbons were the equiaxed cellular type, and the average grain sizes diminished with decreasing the ribbon thickness and powder size. The maximum cooling rates were 2.00×10^5 and 1.26×10^4 K/s for the ribbon with thickness of 30 μm and for the powder with size of 87 μm, respectively.

Parametric Study on the Effect of Aspect Ratio of Selected Cooling Hole Geometries on the Mechanical Response of an Automobile Aluminium Alloy Wheel

Aluminium alloy wheels are increasingly popular for their light weight and good thermal conductivity. Cooling Holes (CH) are introduced to reduce their weight without compromising structural integrity. Literature is sparse on the effect of aspect ratio (AR) of CHs on wheels. This, work, therefore, attempts to undertake a parametric study of the effect of aspect ratio (AR) on the mechanical response of an aluminium alloy wheel with triangular, quadrilateral and oval-shaped CHs. Three-dimensional wheel models (6JX14H2ET42) with triangular, quadrilateral and oval shaped CH (each with CH area of 2229 mm2) were generated, discretized, and analyzed by FEM using Creo Elements/Pro 5.0 to determine the mechanical response at the inboard bead seat at different ARs of 1, 0.5, 0.33 and 0.25, each for quadrilateral-CH and oval-CH, at a static Radial Load of 4750 N and Inflation Pressures of 0.3 and 0.15 MPa, respectively. The study shows that the magnitude of stress and displacement is affected by shape and AR of CH. From the results, it could be established that oval-shaped-CH wheel at AR of 0.5 offers greater prospect in wheel design as it was least stressed and deformed and, that the CH combination with highest integrity was the oval-CH and quadrilateral-CH at AR of 0.5.

The in-situ Ti alloying of aluminum alloys and its application in A356 alloys

This research has investigated the in-situ Ti alloying of aluminum alloys and its application to A356 alloys and wheels through the evaluation of microstructure and mechanical properties. The results showed that stable titanium content can be obtained by adding a small quantity of TiO2 into electrolyte of pure aluminum. Under this approach, a greater than 95% absorptivity of titanium was achieved, and the microstructure of the specimens was changed to fine equiaxed grains from coarse columnar grains in the pure aluminum. In comparison with the tradition A356 alloys and wheels, the corresponding microstructure in the testing A356 alloys and wheels was finer. Although the tensile strength was similar between the testing and the tradition A356 alloys and wheels, the ductility of the former (testing) is superior to that of the later (tradition), leading to an excellent combination of strength and ductility from the testing alloys and wheels.

基于MRAC+PID算法的机器人打磨力跟踪控制研究

针对铝合金轮毂打磨过程中末端执行器气动系统建模不准确以及外部环境干扰导致打磨过程中打磨力稳定性差的问题,提出了一种MRAC+PID混合控制策略来实现对打磨力的跟踪控制。首先对末端执行器进行建模和分析;然后采用MRAC+PID控制策略对末端执行器进行控制,其中通过构造李雅普诺夫函数来设计自适应控制律;最后通过仿真和实验验证了所提方法的有效性。结果表明,MRAC+PID在提高系统的响应速度和抗干扰方面具有良好的控制性能,能够快速准确地跟踪期望打磨力,提高铝合金轮毂的表面打磨质量。

轻质铸造铝合金轮毂热处理变形测试分析

目的精准建立铸造铝合金轮毂各区域的T6热处理变形状态及其最佳检测方法,对热处理态轮毂进行表征研究,探讨铝合金轮毂热处理过程的变形规律,为轮毂工业生产和变形研究提供精确和适宜的变形测试方法。方法根据轮毂的结构特征,将变形检测区域分为外轮缘端面、轮辋、轮辐-轮心3个区域,分别使用三坐标测量机、手持三维激光扫描仪和轮缘轴向高度检测装置对4种不同结构的热处理态轮毂进行变形测试,并对测量结果进行分析。结果铝合金轮毂的热处理变形程度与其自身的结构、尺寸密切相关;外轮缘端面轴向变形主要表现为翘曲变形,呈双波峰波谷的变形规律;距离外轮缘越远的环状轮辋,受轮辐结构影响的凹凸程度逐渐减小,椭圆形趋势增大;轮辐-轮心为轴向凹陷变形;轮缘轴向高度检测装置的测量结果与三坐标测量结果基本一致,误差为±5μm。结论手持扫描仪适用于轮辋/轮辐等平坦曲面的变形测试及整体变形云图化;轮缘轴向高度检测装置适用于工业化在线测试。所使用的测试工具和建立的测试方法可以较好地测试轮毂变形,阐明铝合金轮毂热处理变形规律,为后续轮毂的变形控制和变形测试提供测试基础。

儿童平衡车车轮毂压铸模设计

对儿童平衡车车轮毂进行了工艺分析,确定了制件使用压铸铝合金为原材料,详述了模具压铸机的选择、分型面的确定、浇注与排溢系统的设计、推出机构、侧抽机构、冷却系统及模具工作过程。该模具结构合理、可靠。

低压铸造铝合金车轮晶体不连续问题研究

车轮作为承载车辆全部质量的零部件是重要的安全件,缩松是低压铸造铝车轮较为常见的一种缺陷,建立合理的缺陷检查方法尤为重要。采用渗透探伤、FEA仿真、X光探伤、显微镜分析等方法,对低压铸造铝合金车轮缩松进行检验与分析,明确问题的产生原因;建立低压铸造铝合金车轮缩松问题分析方法,该方法能够有效探测缩松缺陷,防止缺陷车轮流入市场。

铝合金车轮涂装前处理线自动控制系统对涂层性能的影响

为提升铝合金车轮涂装线自动化程度,在涂装前处理引入自动监控系统。确定游离碱、游离酸及锆点的检测方法,依据检测结果自动调整加药量。对比人工与设备检测结果,监控设备运行稳定性。

铝合金车轮涂装前处理工序的节能减排

为提高水资源利用效率,达到节能降耗的目的,对铝合金车轮前处理进行中水回用及逆向补水可行性研究。优化补水管路,严格监控水洗槽电导率及末道水洗菌群污染程度;对铝合金车轮涂膜性能(附着力、硬度、耐碎石冲击、耐CASS试验、耐盐雾性、耐丝状腐蚀性、耐水性、耐湿性及耐洗涤剂)进行测试。结果标明:涂装前处理中水回用及逆向补水工艺稳定,水洗槽电导率及末道水洗含菌量均满足前处理工艺指标要求,涂膜性能合格。

线缆生产设备专用铝合金导轮研制及应用

针对3种不同工艺制备的Φ290×28卧式收线机导轮的材料成分、力学性能和组织性能的测试、生产周期、生产成本及导轮的应用情况等分析,发现定制的6061铝合金材料主要化学成分为1.12%Mg、0.71%Si、0.11%Cu、1.25%Zn及96.34%Al,1.25%Zn使铝合金冲压成形性能有较大改善。精密锻造工艺制备的导轮硬度为124HV,抗拉强度为325MPa,延伸率为14.25%,应变达到14.8%时材料才发生断裂,组织结构均匀致密,无疏松多孔缺陷。与利用铝棒进行机械切削加工和铸造成型切削制备导轮的两种工艺相比,导轮的硬度、抗拉强度、韧性、组织性能大幅度提升,导轮机械综合力学性能好,外观美观光洁度好,动平衡性好,整体质量好,而且生产成本下降50%以上,使用寿命长。可见,利用模具精密锻造铝轮胚体快速成型,经T6热处理和表面强化制备导轮工艺为最佳导轮生产工艺。

低压铸造铝合金轮毂在不同环境中的腐蚀分析及防护

本文探讨了低压铸造铝合金轮毂在多种环境条件下的腐蚀行为及其防护技术措施。通过对比分析铝合金轮毂在不同腐蚀环境下的性能表现,揭示了腐蚀过程中的主要机理和影响因素。为了有效防护铝合金轮毂免受腐蚀损害,本文提出了一系列防护技术措施,通过实验验证表明,这些防护方法能显著提升铝合金轮毂的耐腐蚀性,为轮毂的长期使用和维护提供了有效策略。为此本文的研究成果不仅为铝合金轮毂的腐蚀防护提供了科学依据,也为汽车轮毂材料的选择和后续研究方向提供了参考。

A356铝合金轮毂内部缺陷的在线实时检测

A356铝合金是汽车轮毂生产制造的主要原材料,在铸件冷却过程中容易产生气孔、缩孔等内部缺陷,需要使用X射线探伤设备来检测。在介绍轮毂X射线检测设备的基础上,提出使用背景相减法提取缺陷的技术方案,先用循环引导滤波算法模拟背景图像,然后使用原始图像减去模拟图像,对得到的二值图像经数学形态学后处理,实现缺陷的准确提取。实验结果表明,提出的技术方案通用性强、实时性好,能够用于铝合金轮毂内部缺陷的在线实时检测。

基于响应曲面法的铝轮毂打磨工艺参数优化

为抑制打磨末端振动,提高轮毂表面打磨质量和过程稳定性,进行了以振动抑制为目的的打磨工艺参数优化试验,根据试验结果分析了主要工艺参数(主轴转速、进给速度、法向压力和砂纸粒度)对末端振动加速度的影响规律;利用多元回归方法建立目标函数预测回归模型,基于Design-Expert软件对试验结果进行方差分析,基于响应面法获得的最佳工艺参数组合为主轴转速3000 r/min、进给速度6 mm/s、粒度500目、法向压力13 N。铝轮毂打磨试验表明:预测模型的预测误差小于10%,通过工艺参数优化能够在减小末端振动的同时显著提高表面质量。

铝合金轮毂在典型大气环境中的腐蚀及其防护措施

随着科技发展的日新月异,汽车轮毂也朝着轻量便捷化的方向发展。铝合金因其性能优异,在轮毂上的应用也越来越多,但铝合金轮毂的腐蚀问题仍是一大难题。简述了铝合金轮毂的几种常见腐蚀类型(丝状腐蚀、点腐蚀、晶界腐蚀、应力腐蚀、剥落腐蚀),介绍了大气环境因素对铝合金轮毂腐蚀的影响,描述了不同型号铝合金在国内外典型大气环境下的腐蚀情况和铝合金轮毂采用基体改性和表面处理的防腐措施。

轻质铝合金轮毂分级淬火形性调控策略

为实现轻质铝合金轮毂的热处理变形精准调控,提出了喷淋+入水的新型分级区域淬火新工艺,通过搭建铝合金轮毂分级热处理试验平台及设计轮毂端面变形检测装置,对轻质铝合金轮毂热处理变形特性进行了详细分析。研究结果表明,轮毂内/外轮缘端面变形特性受轮毂结构刚度的影响,内轮缘变形呈现与外轮缘随动的变形特征;受轮毂换热不均匀、内部组织缺陷等影响,整体变形呈现一定的随机特性。在喷淋+入水的新型分级区域淬火新工艺下,轮毂典型监测点力学性能、硬度指标满足国标要求,轮毂外轮缘端面变形最大减幅达41.5%,新工艺可有效改善轻质铝合金轮毂的热处理轮毂端面变形情况。

冷却工艺对大型铝合金轮毂低压铸造缺陷的影响

为探究低压铸造过程中冷却工艺对铝合金大型轮毂缺陷的影响,使用三维软件对其进行建模,并采用ProCAST有限元软件模拟仿真。基于自然冷却条件对充型过程、温度场、凝固场以及缺陷位置进行综合分析。根据仿真结果,设计并添加冷却工艺。优化后的模拟分析结果表明:合理的冷却工艺设置可以保证铸件的顺序凝固,使缩松、缩孔等缺陷大幅减少。并通过试验验证了该冷却工艺的可行性,模拟缺陷位置与实际吻合。

大尺寸铝轮毂多浇道铸造工艺的数值模拟

以实际低压铸造生产的A356铝合金大尺寸轮毂铸件为对象,对单浇道、双浇道和三浇道3种浇注工艺方案进行了充型和凝固模拟。根据模拟结果,分别对比了3个工艺方案的缺陷分布情况、充型效率、晶粒半径大小以及卷气情况。结果表明,三浇道工艺不仅提高了轮毂质量,减少了缺陷,而且大大缩短了生产时间,是有潜力的新工艺。

一种盘式铝合金汽车轮毂锻造工艺设计及锻件组织力学性能分析

设计并优化了一种盘式铝合金汽车轮毂的锻造工艺及模具,结合数值模拟明确了锻造过程中金属的流动规律。针对此类盘式铝合金汽车轮毂的结构特点,提出了一种预锻件-终锻模具内嵌式相切的设计方法。基于此设计方法,通过数值模拟得出了合理的预锻上模压下量为50~70 mm。优化的锻造工艺和模具解决了轮毂初始坯料和预锻件与模具间定位难的问题,并消除了终锻件的折叠缺陷。利用优化后的锻造模具和工艺进行了锻造生产试验,对轮毂终锻件不同部位进行了组织表征和力学性能测试。结果表明,采用提出的预锻模具设计方法及推荐的预锻上模压下量,轮毂锻件成形质量良好,飞边分布均匀且无折叠缺陷,不同部位的组织和力学性能均满足要求。