汽车底盘轻量化材料和工艺

汽车轻量化是汽车行业较为关注的话题。底盘的轻量化不仅有利于降低油耗,对整车舒适性也有很大的提高。当前大量的新材料、新工艺和新技术的应用实现了底盘轻量,其中包括轻质合金材料铝合金和镁合金、先进高强钢材料、塑料材料、热压成形工艺、液压成形工艺以及空心结构零件等。主要从轻量化材料的应用和先进制造工艺两个方面对汽车底盘主要零件轻量化技术的应用现状和发展进行了简要述叙。     

一种铝合金覆盖件拉延成形解决方案

近年来随着汽车制造的飞速发展,汽车业已经成为我国经济发展的支柱产业,车身制造是汽车发展中的重要组成部分,对车用材料、成形工艺、产品质量的要求越来越高.汽车上约70％的零件经冲压工艺制成,因此冲压技术水平的高低决定着车身的品质高低.但随着节能环保理念的不断深入,汽车轻量化制造已成为汽车行业关注的焦点.采用如铝合金等轻质材...     

铝板在车身覆盖件冲压生产中的关键技术

随着汽车轻量化的需求,铝合金材料被越来越多的应用到汽车制造领域。介绍了汽车行业常用2000系、5000系和6000系等铝合金材料,并简述了铝材料开发、在车身零件上的应用趋势,以及对于汽车轻量化的意义。从现场实际出发,通过对铝板材料的剪切、配送、存储、分张、冲压成形以及铝板零件的检修的各环节的现场分析,总结了四个方面的控制要点,即材料保存、板料拆垛、模具冲制、质检返修,并提出了预防材料发霉、解决铝板分张的措施、控制铝板成形质量以及铝板零件检验和返修要点等相应的解决方案。     

铝合金复合材料在汽车轻量化上的应用

推广汽车轻量化,加大铝质配件材料的应用,是我国汽车工业发展的当务之急,对解决我国能源短缺,道路超载、运输效率低下具有很重要的意义.加大铝质配件应用是汽车轻量化的措施之一,分析了汽车轻量化的铝合金材料结构性能,阐述了轻量化以铝为首的轻质材料在汽车上的应用措施,介绍了汽车工业的快速发展将给铝质散热器带来巨大的市场前景,论述了商用车采用铝合金车轮减轻车辆的自重显著,研究了国外汽车制造商大力研发车身轻量化技术,同时指出了轻质材料是汽车安全、节能、环保核心的技术优势和轻量化措施.     

新型低硅TRIP590及TRIP780钢的综合成形性能

随着节能环保和安全性要求的不断提高,使用超高强度钢生产零件以实现轻量化成为了汽车厂商的主要趋势之一.通过对新型低碳低硅相变塑性钢(TRIP590和TRIP780)力学性能、金相组织以及胀形、杯突和扩孔等试验,研究了这两种TRIP钢的成形性能.得到的FLD0值分别达到25.7%和26%;杯突值达到11 mm以上;扩孔率分别达到51%和22%,表明材料具有良好的成形性能.用试验钢冲压复杂车身零件的结果表明,试验钢能够应用于汽车轻量化零件的生产,具有广阔的市场前景.     

钢与铝异种金属的压焊技术研究

随着汽车工业的发展,对汽车节能、环保、安全的要求越来越高,轻量化技术是实现其目标的重要途径.作为汽车轻量化材料中最主要的两类材料,高强度钢板和铝合金组成的钢-铝一体化车身成为轻量化的发展技术路线.综述了钢-铝异种材料在汽车工业中电阻点焊技术的研究现状,重点介绍复合板过渡层法和金属涂层法的工艺方法,利用垫片法探讨了钢-铝...     

热成形技术在汽车轻量化中的应用与发展

高强度钢是汽车轻量化的主要材料,但钢板强度高到一定程度时传统的冷成形技术无法再满足生产需求。随着热成形技术的应用,汽车高强度钢得到了长足的发展。本文立足于汽车的轻量化理念,介绍了热成形技术的研究现状,以及热成形技术在先进高强度钢中的应用与发展。     

专注管件成形,以卓越品质助力中国制造

管材液压成形(也称内高压成形)是使用液体对管材施加压力,使其在模具中成形的一种塑性加工技术.与传统工艺相比,管材液压成形可以做出很多刚性模具无法成形的复杂零件,此外,液压成形的零件具有轻量化、高强度等优点,可以减少料耗,工艺过程稳定,产品一致性好,在汽车排气、底盘、车身零部件中获得广泛应用.     

高强度变截面加强板成形的回弹和开裂

由于资源和环境等原因．近年来汽车界在减轻整车重量、节约油耗方面投入了大量精力。汽车既要求轻量化,同时又要求保证车身结构的强度和安全性,因而高强度钢板在现代汽车领域得到越来越广泛的应用。随着材料强度的提高．钢板成形性能总体呈下降趋势．成形难度加大。高强板零件拉延开裂．扭曲回弹尤其难以解决．特别是变截面类和窄长梁类零件。扭曲回弹、开裂是一个长期困扰;中压领域的难题。     

最新高强度弹簧钢的研制

0前言 　　近年来,对于汽车轻量化的需求日益增高,即使在作为汽车悬挂系零件用的悬挂螺旋弹簧方面,为应对轻量化的发展趋势,也在努力实施材料的高强度化.目前,设计应力1300 MPa级的高强度弹簧钢被实际应用着.而继续实施材料开发的目的,是进一步实现轻量化与低成本化. 　　……     

Effects of Post-weld Heat Treatment on Microstructure,Mechanical Properties and the Role of Weld Reinforcement in 2219 Aluminum Alloy TIG-Welded Joints

In as-welded state, each region of 2219 aluminum alloy TIG-welded joint shows diff erent microstructure and microhardness due to the diff erent welding heat cycles and the resulting evolution of second phases. After the post-weld heat treatment, both the amount and the size of the eutectic structure or θ phases decreased. Correspondingly, both the Cu content in α-Al matrix and the microhardness increased to a similar level in each region of the joint, and the tensile strength of the entire joint was greatly improved. Post-weld heat treatment played the role of solid solution strengthening and aging strengthening. After the post-weld heat treatment, the weld performance became similar to other regions, but weld reinforcements lost their reinforcing eff ect on the weld and their existence was more of an adverse eff ect. The joint without weld reinforcements after the post-weld heat treatment had the optimal tensile properties, and the specimens randomly crack in the weld zone.     

The First Phase of the SRIF Industrialized Base in ＂West Area＂ Has Been Put into Operation

After nearly two years＇ tense construction, the first phase of industrialized base of Shenyang Research Institute of Foundry （SRIF）, located at the Tiexi Casting and Forging Industrial Park in the west of Tiexi District, has now been completed and formally put into operation.     

新型的治疗阿尔茨海默氏症药物(1-二甲基磷酰基-2,2,2-三氯)-乙基-1-醇烟酸醋对体外神经细胞的作用

目的: 观察本实验室合成的一种治疗阿尔茨海默氏症(AD)的药物(1-二甲基磷酰基-2, 2, 2 -三氯)-乙基^-1-醇烟酸醋(NMF),对体外培养的皮层神经细胞活性的影响以及对海人藻酸(KA)所致的神经损伤的保护作用。方法: 采用体外培养皮层神经元的方法,解剖分离 15 d胚胎小鼠皮层神经细胞, 接种于 96孔板,48 h 后加药并培养 72 h,以 MIT 法 观察 NMF 对小鼠皮层神经细胞活性的影响;同时将接种于 24 孔板的细胞预先给予 NMF,d 3 时加或不加KA处理后,以台盼蓝染色鉴别并计数死、活细胞,可得出细胞的存活率。结果: NMF 明显促进胎鼠皮层神经元活性,其中 NMF1、0. 1、10nmol·L^-1促进神经元活性增殖率分别高达 34.7%、37.4%、36. 7%, NMF 明显促进正常胎鼠皮层神经元存活卒,与对照组比较,10nmol·L^-1 NMF 对皮层神经元的存活率分别提高 39.3%、73.5%。 NMF能显著 对抗 KA 所致的神经元损伤,与 KA 损伤组相比, NMF0.1、10、10nmol·L^-1对损伤皮层神经元的保护率分别为 77.30%、80.10%、84.15%。结论: NMF 明 显促进胎鼠皮层神经元的洁性、提高正常皮层神经元,的存活卒,并能有效地保护KA所致的神经元损伤,提示 NMF 是一种很有潜力的治疗 AD 的药物。     

THERMODYNAMICS STUDY ON THE DECOMPOSITION OF CHROMITE WITH KOH

Institute of Process Engineering, Chinese Academy of Sciences, China, has proposed a method for oxidative leaching of chromite with potassium hydroxide. Understanding the mechanism of chromite decomposition, especially in the potassium hydroxide fusion, is important for the optimization of the operating parameters of the oxidative leaching process. A traditional thermodynamic method is proposed and the thermal decomposition and the reaction decomposition during the oxidative leaching of chromite with KOH and oxygen is discussed, which suggests that chromite is mainly destroyed by reactions with KOH and oxygen. Meanwhile, equilibrium of the main reactions of the above process was calculated at different temperatures and oxygen partial pressures. The stable zones of productions, namely, K2CrO4 and Fe2O3, increase with the decrease of temperature, which indicates that higher temperature is not beneficial to thermodynamic reactions. In addition, a comparison of the general alkali methods is carried out, and it is concluded that the KOH leaching process is thermodynamically superior to the conventional chromate production process.     

INFLUENCE OF HEAT TREATMENT ON DAMPING BEHAVIOUR OF THE MAGNESIUM WROUGHT ALLOY AZ61

The effect of isochronal heat treatments for 1h on variation of damping, hardness and microstructural change of the magnesium wrought alloy AZ61 was investigated. Damping and hardness behaviour could be attributed to the evolution of precipitation process. The influence of precipitation on damping behaviour was explained in the framework of the dislocation string model of Granato and Lücke.     

Theoretical Analysis for the Motion and Temperature of Melt Droplets in Spray Degassing Process

The motion of melt droplets in spray degassing process was analyzed theoretically. The height of the treatment tank in spray degassing process could be determined by the results of theoretical calculation of motion of melt droplets. To know whether the melt droplets would solidify during spraying process, the balance temperature of melt droplets was also theoretically analyzed. Then proof experiments for theoretical results about temperature of melt droplets were carried. In comparison, the experimental results were nearly similar to the calculation results.     

Growth Kinetics of Single Inclusion Particle in Molten Melts

On the basis of the single-particle framework, a new theory on inclusion growth in metallurgical melts is developed to study the kinetics of inclusion growth on account of reaction and collision. The studies show that the early growth of inclusion depends on reaction growth and Brawnian motion collision, and where the former is decisive, the late growth depends on turbulence collision and Stokes＇ collision, and where the former is dominant; collision growth is very quick during the smelting process, lessened in the refining process, but nearly negligible in the continuous casting process.     

An Easy Way to Quantify the Adhesion Energy of Nanostructured Cu/X(X=Cr,Ta,Mo,Nb,Zr) Multilayer Films Adherent to Polyimide Substrates

An approach based on film buckling under simple uniaxial tensile testing was utilized in this paper to quantitatively estimate the interfacial energy of the nanostructured multilayer films(NMFs) adherent to flexible substrates. The interfacial energies of polyimide-supported NMFs are determined to be *5.0 J/m2 for Cu/Cr, *4.1 J/m2 for Cu/Ta,*2.8 J/m2 for Cu/Mo, *1.1 J/m2 for Cu/Nb, and *1.2 J/m2 for Cu/Zr NMFs. Furthermore, a linear relationship between the adhesion energy and the interfacial shear strength is clearly demonstrated for the Cu-based NMFs, which is highly indicative of the applicability and reliability of the modified models.     

High-Speed Friction Stir Welding of SiC_p/Al–Mg–Si–Cu Composite

A 17 vol% SiCp/Al–Mg–Si–Cu composite plate with a thickness of 3 mm was successfully friction stir welded(FSWed) at a very high welding speed of 2000 mm/min for the first time. Microstructural observation indicated that the coarsening of the precipitates was greatly inhibited in the heat-affected zone of the FSW joint at high welding speed, due to the significantly reduced peak temperature and duration at high temperature. Therefore, prominent enhancement of the hardness was achieved at the lowest hardness zone of the FSW joint at this high welding speed, which was similar to that of the nugget zone. Furthermore, the ultimate tensile strength of the joint was as high as 369 MPa, which was much higher than that obtained at low welding speed of 100 mm/min(298 MPa). This study provides an effective method to weld aluminum matrix composite with superior quality and high welding efficiency.     

Three-Dimensional Growth of Coherent Ferrite in Austenite: A Molecular Dynamics Study

Coherent second phase often exhibits anisotropic morphology with specifi c orientations with respect to both the second and the matrix phases. As a key feature of microstructure, the morphology of the coherent particles is essential for understanding the second-phase strengthening eff ect in various industrial alloys. This letter reports anisotropic growth of coherent ferrite from austenite matrix in pure iron based on molecular dynamics simulation. We found that the ferrite grain tends to grow into an elongated plate-like shape, independent of its initial confi guration. The fi nal shape of the ferrite is closely related to the misfi t between the two phases, with the longest direction and the broad facet of the plate being, respectively, consistent with the best matching direction and the best matching plane calculated via the Burgers vector content(BVC) method. The strain energy calculation in the framework of Eshelby's inclusion theory verifi es that the simulated orientation of the coherent ferrite is energetically favorable. It is anticipated that the BVC method will be applicable in analysis of anisotropic growth and morphology of coherent second phase in other phase transformation systems.