Significance-based optimization of processing parameters for thin-walled aluminum alloy tube NC bending with small bending radius

Thin-walled aluminum alloy tube numerical control （NC） bending with small bending radius is a complex process with multi-factor coupling effects and multi-die constraints. A significance-based optimization method of the parameters was proposed based on the finite element （FE） simulation, and the significance analysis of the processing parameters on the forming quality in terms of the maximum wall thinning ratio and the maximum cross section distortion degree was implemented using the fractional factorial design. The optimum value of the significant parameter, the clearance between the tube and the wiper die, was obtained, and the values of the other parameters, including the friction coefficients and the clearances between the tube and the dies, the mandrel extension length and the boost velocity were estimated. The results are applied to aluminum alloy tube NC bending d50 mm×1 mm×75 mm and d70 mm×1.5 mm×105 mm （initial tube outside diameter D0 × initial tube wall thickness t0 × bending radius R）, and qualified tubes are produced.

Anodizing parameters for superheated slurry cast 7075 aluminum alloys

The anodizing parameters of voltage, current density, temperature, and electrolyte choice were assessed to find an appropriate combination for the superheated slurry cast 7075 Al alloy substrate.The alloy was anodized in sulfuric acid electrolyte or alternatively in sulfuric acid mixed with boric acid or citric acid. The voltages applied were in the range of 15-30 V. Anodizing current densities tested were 2 and 3 A/dm^2,while temperatures tested were 5 and 15 ℃. Thickness, surface morphology, hardness,and corrosion resistance of the oxide film were then evaluated.It was found that 25 V,2 A/dm^2 and 5 ℃ were suitable for this alloy when anodized in sulfuric acid. The oxide film was smooth with uniform thickness, low porosity, high hardness,and had the highest corrosion resistance at these parameters. However, discontinuous oxide films were observed from samples anodized at higher temperature of 15 ℃.Alternative electrolytes considered were sulfuric acid mixed with boric acid or citric acid. The results showed that electrolytes with boric acid or citric acid increased thickness, hardness, corrosion resistance and quality of the oxide films.However, these oxide films were inferior to those obtained with sulfuric acid electrolyte at lower temperature(25 V, 2 A/dm^2 and5 ℃).

Die Casting Mold Design of the Thin-walled Aluminum Case by Computational Solidification Simulation

Recently, demand for the lightweight alloy in electric/electronic housings has been greatly increased. However, among the lightweight alloys, aluminum alloy thin-walled die casting is problematic because it is quite difficult to achieve sufficient fluidity and feedability to fill the thin cavity as the wall thickness becomes less than 1mm. Therefore, in this study, thin-walled die casting of aluminum （Al-Si-Cu alloy： ALDC 12） in size of notebook computer housing and thickness of 0.8 mm was investigated by solidification simulation （MAGMA soft） and actual casting experiment （Buhler Evolution B 53D）. Three different types of gating design, finger, tangential and split type with 6 vertical runners, were simulated and the results showed that sound thin-walled die casting was possible with tangential and split type gating design because those gates allowed aluminum melt to flow into the thin cavity uniformly and split type gating system was preferable gating design comparing to tangential type gating system at the point of view of soundness of casting and distortion generated after solidification. Also, the solidification simulation agreed well with the actual die-casting and the casting showed no casting defects and distortion.

Near net shape casting process for producing high strength 6xxx aluminum alloy automobile suspension parts

The automobile suspension parts of a high strength 6xxx aluminum alloy were produced using a novel technique known as near net shape casting for forging stock preparation. Based on the outline dimension of the forging stock, the shape of the ingot was designed as the near net shape and its casting process was studied by the numerical simulation and experimental investigation. The results show that the shrinkage of the ingot was highly correlated to its shape parameters and could be successfully forecast by the stimulation model. The casting parameters of the near net shape ingot were optimized and the near net shape 6xxx aluminum alloy ingots free of defects were cast in the laboratory. In order to obtain high performance forged suspension parts, the hot compression tests of the ingot were carried out. The results show that the subgrain fraction of the forged ingot was strongly affected by Zener-Hollomon parameters （Z parameters）. The intermediate Z parameters, 1.09×10^16 s^-1, will contribute to the larger number fraction of subgrains inside the forged ingot, which contributes to the high performance of the forged products.

Induction reheating of A356.2 aluminum alloy and thixocasting as automobile component

The development work for producing an automobile component by thixocasting using A356.2 alloy was introduced.As the first step,the alloy was electromagnetically stirred and solidified to produce a billet with non-dendritic microstructure.The microstructure depended on several process parameters such as stirring intensity,stirring frequency,cooling rate,and melt initial superheat.Through a series of computational studies and controlled experiments,a set of process parameters were identified to produce the best microstructures.Reheating of a billet with non-dendritic microstructure to a semisolid temperature was the next step for thixo-casting of the components.The reheating process was characterized for various reheating cycles using a vertical-type reheating machine.The induction heating cycle was optimized to obtain a near-uniform temperature distribution in radial as well as axial direction of the billet,and the heating was continued until the liquid fraction reached about 50%.These parameters were determined with the help of a computational fluid dynamics(CFD) model of die filling and solidification of the semisolid alloy.The heated billets were subsequently thixo-cast into automobile components using a real-time controlled die casting machine.The results show that the castings are near net shape,free from porosity,good surface finish and have superior mechanical properties compared to those produced by conventional die casting processes using the same alloy.

Machining studies of die cast aluminum alloy-silicon carbide composites

Metal matrix composites （MMCs） with high specific stiffness, high strength, improved wear resistance, and thermal properties are being increasingly used in advanced structural, aerospace, automotive, electronics, and wear applications. Aluminum alloy-silicon carbide composites were developed using a new combination of the vortex method and the pressure die-casting technique in the present work. Machining studies were conducted on the aluminum alloy-silicon carbide （SiC） composite work pieces using high speed steel （HSS） end-mill tools in a milling machine at different speeds and feeds. The quantitative studies on the machined work piece show that the surface finish is better for higher speeds and lower feeds. The surface roughness of the plain aluminum alloy is better than that of the aluminum alloy-silicon carbide composites. The studies on tool wear show that flank wear increases with speed and feed. The end-mill tool wear is higher on machining the aluminum alloy-silicon carbide composites than on machining the plain aluminum alloy.

Effect of depressurizing speed on mold filling behavior and entrainment of oxide film in vacuum suction casting of A356 alloy

The effect of depressurizing speed on mold filling behavior and entrainment of oxide film of A356 alloy was studied. Themold filling behavior and velocity fields were recorded by water simulation with particle image velocimetry. The results show thatthe gate velocity first increased dramatically, then changed with the depressurizing speed: the gate velocity increased slowly atrelatively high depressurizing speed; at reasonable depressurizing speed, the gate velocity kept unchanged; while at lowerdepressurizing speed, the gate velocity decreased firstly and then kept unchanged. High gate velocity results in melt falling backunder gravity at higher speed. The falling velocity is the main factor of oxide film entrainment in vacuum suction casting. The designcriterion of depressurizing rate was deduced, and the A356 alloy castings were poured to test the formula. The four-point bend testand Weibull probability plots were applied to assessing the fracture mechanisms of the as-cast A356 alloy. The results illuminate amethod on designing suitable depressurizing speed for mold filling in vacuum suction casting.

考虑铣削振动的薄壁件表面加工质量试验研究

薄壁件刚性较低,其铣削时产生的振动是加工中不可忽略的因素。为保证加工精度和表面加工质量,合理选用铣削参数是十分重要的。在考虑铣削振动的基础上,将7075铝合金薄壁件铣削时产生的加速度作为分析铣削振动的依据,以工件的表面粗糙度为最终指标,通过试验综合分析切削深度、每齿进给量和主轴转速等铣削参数对薄壁件表面加工质量的影响。试验结果表明:随着这3个铣削参数值增大,铣削振动和表面粗糙度均会增大。其中每齿进给量对工件振动的幅度,以及表面粗糙度的影响最为显著,因此,减小每齿进给量能有效降低铣削振动,减小表面粗糙度,从而保证薄壁件的加工质量。

ZL101/6061铝合金搅拌摩擦焊接头组织及性能研究

采用搅拌摩擦焊接ZL101铸造铝合金和6061铝合金,转速为1000 r/min,研究不同焊接速度和压入量对铝合金接头组织和性能的影响。结果表明:当焊接速度为150 mm/min,压入量为6 mm时,铝合金接头的成型较美观;接头主要以α(Al)相为基体,在基体上分布着Al4Si第二相;铝合金接头的抗拉强度达到最大值,为92.53 MPa;焊接接头的硬度总体上呈“W”趋势,焊核区硬度高,热机械影响区的硬度略微下降,热影响区的硬度又有所回升。此工艺参数条件下铝合金接头的耐腐蚀性能最好,自腐蚀电位和自腐蚀电流密度分别为-0.6933 V和3.17×10^(-7) A/cm^(2)。

工艺参数对铸态7075铝合金管旋压成形强度的影响

工艺参数对铸态7075铝合金管旋压成形强度的影响至关重要。本文以抗拉强度与屈服强度作为成形质量指标,系统地分析了压下量、预热温度、进给比和摩擦条件等工艺参数对铸筒旋压件强度的影响。结果表明:随着压下量的增加,管的抗拉强度与屈服强度增加;随着预热温度的上升或者进给比的增加,管的抗拉强度与屈服强度先增加后减少;随着摩擦系数的增加,管的抗拉强度与屈服强度先增加后减少,但变化不明显。

工艺参数对7050铝合金铣削表面质量的影响

为了探究7050铝合金铣削表面质量的关键影响因素,寻找最优工艺参数,对7050铝合金在浇注冷却条件下进行了正交试验,建立了表面粗糙度与切削深度、主轴转速之间的回归模型,分析了加工过程中刀具-工件相对接触状态不同时所产生的刀痕差异。结果表明:切削深度对表面粗糙度的影响最大,主轴转速其次,进给量的影响最小;刀痕的表现形式与刀具-工件相对接触状态存在直接联系,刀具切入工件位置主要受切削深度的影响产生单向圆弧状刀痕,刀具完全进入铣削工件后则会形成交错的圆弧状刀痕,在刀具离开工件位置主要受进给量影响产生较浅刀痕。

基于ProCAST汽车铝合金轮毂铸造数值模拟及其优化

使用UGNX软件建立汽车铝合金轮毂三维模型。基于ProCAST软件进行铝合金轮毂低压铸造工艺数值模拟仿真,对模拟中铝合金低压铸造温度场、凝固场和容易形成缩松、缩孔的缺陷分布进行研究。在数值模拟结果的基础上,调整了浇注温度、冷却系统、充型压力。铸造工艺参数优化后模拟分析显示,铝合金轮毂的缩孔、缩松等缺陷显著减少,极大改善了铸件的质量,为汽车铝合金轮毂生产制造提供了较为合理的工艺参数。

铝合金薄壁角片数控加工方案分析与论证

对小型铝合金薄壁角片零件的结构与材料进行了工艺性分析,设计出两种数控加工工艺方案。通过对两种加工方案所采用的加工方法进行整体论证,对比得出一种高质量的适合批量生产的加工方案,并总结出最优的数控铣切的切削参数。

航空集装箱用7021铝合金大扁锭产生裂纹的原因及对策

7021铝合金以其优良的特性广泛应用于航空集装箱.随着产品尺寸增加,所需的超大规格扁锭易出现裂纹缺陷.本试验观察了7021铝合金扁锭裂纹形貌,系统分析了合金熔铸过程中的化学成分、熔体质量、铸造工具和工艺对裂纹的影响,提出了解决7021铝合金扁锭裂纹的工艺优化方向以及有效控制措施.

铝合金耐磨性能与铸造性能的研究

铝合金耐磨性能具有物理性以及力学性等优势,能够满足不同行业应用需求,特别在飞机以及航空金属结构材料应用方面都是主要原材料。但是在实际过程中铝合金会存在机械构建磨损大等弱点,这对整体构件铸造性能带来影响,导致应用范围受限,本文对铝合金耐磨性能与铸造性能进行研究,以为相关工作人员提供参考。

5系高镁合金扁锭铸造垂直褶皱裂纹的原因分析及改进措施

介绍铝合金扁锭铸造过程中铸锭表面出现垂直褶皱缺陷的机理,得到不同系别的铝合金在铸造过程中及使用不同过滤器(管式过滤器、板式过滤器)时,铸锭垂直褶皱裂纹的产生趋势,由此分析了高镁铝合金铸造过程中褶皱裂纹产生的主要原因。通过试验验证,找到解决裂纹敏感性较高的5系高镁合金在铸造过程中产生褶皱裂纹的措施,并应用于实际生产中,有效地防止铸造过程中褶皱裂纹的产生。

6061-T6铝合金铣削参数对切削性能影响的有限元仿真与实验分析

铣削加工作为五金行业中常见的加工技术,其切削参数的合理选择不仅能提高刀具的加工效率,还会显著影响生产成本和产品质量。基于此,本研究利用有限元仿真与实验方法探讨6061-T6铝合金铣削过程中不同参数对切削性能的影响。通过建立6061-T6铝合金的有限元模型,分析铣削深度、铣削宽度和主轴转速对切削力和温度的影响。研究表明,切削深度对切削力影响最大,而铣削宽度对温度影响最显著。仿真结果与实验数据的偏差保持在30%以内,表明仿真数据具有较高的可信度。这证明仿真模型能有效反映实际铣削过程,为6061-T6铝合金的铣削加工提供理论依据和实践指导,有助于工业应用中铣削参数的优化和控制。

铝合金汽车零部件挤压铸造工艺参数优化及性能评价

本文研究了铝合金汽车零部件挤压铸造工艺的关键参数优化及其对零件性能的影响。通过正交试验设计,研究了挤压速度、模具温度、液态金属温度等工艺参数对零件力学性能、内部缺陷、表面质量的影响规律。研究表明,适当提高挤压速度和液态金属温度,并降低模具温度,可以在保证零件力学性能的同时获得良好的表面质量,并最小化内部缺陷。本研究可为铝合金汽车零部件的挤压铸造工艺优化提供理论指导和数据支撑。

铝合金支架零件压铸工艺研究

通过分析铝合金材料特性及其在压铸中的适用性,阐述了压铸工艺的基本原理和流程。重点从铝合金材料选择、压铸模具设计、工艺参数控制和后处理优化等方面,对铝合金支架零件压铸生产的关键工艺要点进行了系统研究。结果表明,优化铝合金材料成分和熔体质量,改进压铸模具的分型面设计、浇注系统布局和冷却水道参数,精确控制射速、射压、保压、温度等工艺参数,并采取合理的后处理措施,可显著提高铝合金支架零件的尺寸精度、表面质量和力学性能,实现压铸工艺的全面优化。

端铣加工参数对铝合金表面粗糙度的影响研究

为研究端铣加工参数对铝合金表面粗糙度值的影响,采用正交试验方法对铝合金进行铣削试验。试验结果表明:在机床恒转矩区时,主轴转速是表面粗糙度的最大影响因素;在机床恒功率区时,进给速度对表面粗糙度的影响最大,主轴转速的影响最小。建立无量纲化计算公式,以低粗糙度值和高材料去除率为条件,得到了端铣加工铝合金的最优化加工参数。