附录A
The significance of lightweight
Automotive lightweight main guiding principle: to ensure stability on basis of improved performance, energy-saving design of the assembly partscontinuous optimization model spectrum.
The lightweight car, the car is to ensure strength and security of the premise, as far as possible to reduce the car's curb weight, thereby enhancing the car's power, reducing fuel consumption and reduce exhaust pollution. Experiments show that if 10% of automobile weight reduction, fuel efficiency can bincreased by 6% -8%; vehicle curb weight is reduced by 100 kg hundred kilometers can be reduced 0.3-0.6 liters; 1% of vehicle weight reduction, fuel consumption can be reduced 0.7 %. At present, due to the need for environmental protection and energy saving, lightweight car has become the world trend of automobile development.
Lightweight car is the main way:
①mainstream car models continue to optimize the size, specification size to retain the main parameters of the premise, to enhance the structural strength of the vehicle, reducing the amount of supplies;
② use of lightweight materials. Such as aluminum, magnesium, ceramic, plastic, fiberglass or carbon fiber composite materials;
③ The computer design. Such as finite element analysis, local reinforcement design;
④ the use of load-bearing body, thinning the thickness of the body sheet metal.design翻译
Among them, the current major automotive lightweight measures mainly the use of lightweight materials. for automotive lightweight design of the metal material
The main vehicle through the car's lightweight materials to improve economy to contribute. Theoretical analysis and experimental results show thlightweight is to improve vehicle fuel economy and effective way. In order to equirements of lightweight vehicles, some new material emerged and expanded the scope of application.
Nonferrous Alloys
To passenger cars, the 1973 vehicle used by the non-ferrous alloy of the total timber weight ratio of 5.0% in 1980 to 5.6%, while in 1997 it reachNon-ferrous alloys in automotive applications is the rapid growth trend of development of automotive materials. Aluminum
Steel aluminum density of about 1 / 3 is the most widely used lightmaterials. United States production of automotive products, for example, aluminum alloy 1976 per vehicle is only 39kg, 1982 reached 62kg, while in 1998 it reach100kg.
(1) cast aluminum alloy
Many elements can be used as cast aluminum alloy elements, only Si, Cu, Mg, Mn, Zn, Li in the mass production of great significance. Of course, widely used in the car is not the simple binary alloy but also a variety of elements added to obtain a good overall performance.
The automobile industry is the main market of aluminum castings, such as Japan, 76% of aluminum castings, aluminum die casting 77% of automotive castings. Mainly used in aluminum alloy engine block castings, cylinder heads, pistons, intake manifold, rocker arms, engine mount bracket, air compressor connecting rod, clutch housings, clutch housings, wheels, brake parts, handles and cover shell-type parts and so on.
Aluminum casting inevitably flawed, casting can not be heat treated produce a result in the use of higher strength aluminum alloy castings is limited. On the casting for this production process has been improved, semi-solid casting forging forming method and method will be used to craft the future
more.
(2) deformation of aluminum alloy
Refers to deformation of aluminum alloy aluminum alloy plate and extrusions and forging materials, mainly used in automotive body panels on the boengine radiators, air conditioning condenser, evaporator, wheels, trim and suspension parts.
As the effect is obvious lightweight, aluminum alloy car body applications is expanding. September 1990 as the Japanese started selling cars with a Honda NSX Unibody aluminum, cold rolled steel plate than in the same light 200kg body attracted worldwide attention. NSX to the entire vehicle with aluminum 31.3%, as in the aluminum car body, using the 6000 series alloy outer plate, inner plate with 5052-0 alloy, most use the 5182-0 alloy frame; that the side door of the strength and stiffness requirements are high, the use of the 6N01 alloy-based, appropriate adjustments to the Mg and Si content of the alloy. Also useful in Europe and America for 2036 and 2008 alloy plates inside and outside the body. Aluminum radiator originated in Europe and then throughout the world. In Europe, after the 1980s, aluminum radiator has occupied 90% of the market. With? Car air conditioning, oil coolers, etc. The extensive use of aluminum heat exchangers market is rapidly expanding. From the
material point of view, aluminum heat exchangers in a wide range of coating material applied to a large extent due to aluminum and aluminum cladding successful development.
(3) aluminum matrix composites
Low density of aluminum matrix composites, strength and high modulus, good thermal fatigue properties, but in automotive applications by the price and production quality control and other constraints, have not formed a large scale. Currently, aluminum matrix composites in the connecting rod, piston, cylinder body holes, brake discs, brake calipers and other parts of the drive shaft tube test or showing superior performance, such as developed by Honda does not? Enhanced aluminum matrix composite wire rod steel rod down more than 30% weight on the 1.2L gasoline engine can increase fuel economy 5%; using chilled aluminum powder and SiC powder (weight percentage of 2%) and mixed extruded into rods, forged with the shape of the piston rod for high strength can be 20% lower weight, engine power has increased significantly; composite enhanced with aluminum piston head to cancel the first ring groove of austenitic cast iron inserts can drop weight 20%; aluminum matrix composite brake discs reduce weight than cast iron brake disc 50%.
Magnesium
Aluminum magnesium density of about 2 / 3, in the practical application of the metal is the lightest. Vibration absorption of magnesium alloy cutting ability is good, metal casting
performance, it is suitable for manufacturing automotive parts.
Most of the die casting magnesium alloy in the form of applications in the car, magnesium die casting aluminum production efficiency than the 30% to 50%. The newly developed non-porous casting method (Pore Free Diecast) can produce no holes and can be heat-treated magnesium die castings.
Magnesium castings used in the car the earliest examples is the wheel rim. In the car on the trial or application instance there magnesium alloy clutch housing, clutch pedal, brake pedal mounting bracket, dashboard frame, seat, steering column parts, steering wheel round core, transmission housing, engine mounts, cylinder head and cylinder head cover and so on. With the traditional system of the steering column bracket compared to the zinc, magnesium and heavy parts down 65%; with traditional steel steering wheel core compared to 45 percent weight reduction of magnesium parts; compared with the aluminum cylinder head, magnesium parts 30% weight reduction; traditional stamping and welding structural steel brake pedal bracket compared to the overall weight of magnesium castings down 40%, while its rigidity is also improved.
Magnesium matrix composites has also made progress, with SiC particles as reinforcement, mixing technology is the use of liquid magnesium-based composite materials with good performance and lower production costs. In the AZ91 alloy by adding 25% SiC particle reinforced composites than the matrix alloy with 23% higher tensile strength, yield strength increased 47%, elastic modulus increased 72%.
Titanium
Titanium density 4.5g/cm3, with high strength, high temperature strength and corrosion resistance and so on. Because titanium is expensive, since I saw the car in the luxury car and a small amount of individual applications. However, the application of titanium in the test car has a lot of research work. For example, with α + β titanium alloy of the engine connecting rod system, the equivalent strength quenched and tempered steel 45 levels, and weight can be reduced 30%; β of titanium (Ti-13V-11Cr-3Al, etc.) and time by the strong cold treatment, intensity of up to 2000MPa, can be used to manufacture suspension springs, valve springs and valves, etc., and the tensile strength of 2100MPa of high strength steel than titanium springs can be 20% lower weight.
The biggest obstacle to the application of titanium from its high price, Toyota Central Research Institu
te has developed a low-cost titanium matricomposites. The composite material to Ti-6Al-4V alloy matrix to the reinforcements powder metallurgy method of production, has been applied in the engine connecting rod.
附录B
轻量化的意义
汽车轻量化主要指导思想：在确保稳定提升性能的基础上，节能化设计各总成零部件，持续优化车型谱。
汽车的轻量化，就是在保证汽车的强度和安全性能的前提下，尽可能地降低汽车的整备质量，从而提高汽车的动力性，减少燃料消耗，降低排气污染。实验证明，若汽车整车重量降低10%，燃油效率可提高6%—8%；汽车整备质量每减少100公斤，百公里油耗可降低0.3—0.6升；汽车重量降低1%，油耗可降低0.7%。当前，由于环保和节能的需要，汽车的轻量化已经成为世界汽车发展的潮流。
汽车轻量化的主要途径是：
①汽车主流规格车型持续优化，规格主参数尺寸保留的前提下，提升整车结构强度，降低耗材用量；
②采用轻质材料。如铝、镁、陶瓷、塑料、玻璃纤维或碳纤维复合材料等；
③采用计算机进行结构设计。如采用有限元分析、局部加强设计等；
④采用承载式车身，减薄车身板料厚度等。
其中，当前的主要汽车轻量化措施主要是采用轻质材料。
可用于汽车轻量化设计的金属材料
车用材料主要通过汽车的轻量化来对燃料经济性改善作出贡献。理论分析和试验结果都表明，轻量化是改善汽车燃料经济性的有效途径。为了适应汽车轻量化的要求，一些新材料应运而生并扩大了应用范围。
有合金
以乘用车来说，1973年每辆车所使用的有合金占全部用材的重量比为
5.0%1980年增至5.6%，而1997年则达到了9.6%。有合金在汽车上应用量的快速增长是汽车材料发展的大趋势。
铝合金
铝的密度约为钢的1/3，是应用最广泛的轻量化材料。以美国生产的汽车产品为例，1976年每车用铝合金仅39kg，1982年达到62kg，而1998年则达到了100kg。
（1）铸造铝合金
许多种元素都可以作为铸造铝合金的合金元素，但只有Si、Cu、Mg、Mn、Zn、Li在大量生产中具有重要意义。当然，在汽车上广泛应用的并不是上述简单的二元合金而是多种元素同时添加以获得好的综合性能。
汽车工业是铝铸件的主要市场，例如日本，铝铸件的76%、铝压铸件的77%为汽车铸件。铝合金铸件主要应用于发动机气缸体、气缸盖、活塞、进气歧管、摇臂、发动机悬置支架、空压机连杆、传动器壳体、离合器壳体、车轮、制动器零件、把手及罩盖壳体类零件等。
铝铸件中不可避免地存在缺陷，压铸件还不能热处理，因此在用铝合金来生产要求较高强度铸件时受到限制。为此在铸件生产工艺上作了改进，铸造锻造法和半固态成型法将是未来较多用的工艺。
（2）变形铝合金
变形铝合金指铝合金板带材、挤压型材和锻造材，在汽车上主要用于车身面板车身骨架、发动机散热器、空调冷凝器、蒸发器、车轮、装饰件和悬架系统零件等。
由于轻量化效果明显，铝合金在车身上的应用正在扩大。如1990年9月开始销售的日本本田NSX车采用了全铝承载式车身，比用冷轧钢板制造的同样车身轻200kg引起全世界的瞩目。NSX全车用铝材达到31.3%，如在全铝车身上，外板使用6000系列合金，内板使用5052－0合金，骨架大部使用5182－0合金；由于侧门框对强度和刚度要求很高，使用以6N01合金为基础、适当调整了Mg和Si含量的合金。在欧美也有用2036和2008合金作车身内外板的。
铝散热器发源于欧洲而后遍及全世界。在欧洲，到20世纪80年代后期铝散热器已占领市场的90%。随?车用空调、油冷却器等的大量使用，铝热交换器的市场迅速扩大。从材料的角度看，铝在热交换器上的广泛应用在很大程度上归功于包覆料覆层铝板和铝带的成功开发。
（3）铝基复合材料
铝基复合材料密度低、比强度和比模量高、抗热疲劳性能好，但在汽车上的应用受到价格及生产质量控制等方面的制约，还没有形成很大的规模。目前，铝基复合材料在连杆、活塞、气缸体内孔、制动盘、制动钳和传动轴管等零件上的试验或使用显示出了卓越的性能，如本田公司开发成功的由不?钢丝增强的铝基复合材料连杆比钢制连杆降重30%，对1.2L的汽油发动机可提高燃料经济性5%；采用激冷铝合金粉末与SiC粉末（重量百分数2%）混合并挤压成棒材，用此棒材经锻造成型的活塞因强度高可降重20%，发动机功率大幅度提高；用铝基复合

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