Needless to say, lightweight has become the development trend of new energy vehicles in the future. October 2016, the National Strategic AdvIsory Committee powers, Tsinghua University Professor Ouyang Ming Gao as a representative Issued the “energy-saving and new energy vehicle technology road map” of concern, obviously, the development of lightweight technology has rIsen to the national level.
wherein roadmap includes lightweight energy technology, including vehicles, pure electric and hybrid vehicles, fuel cell vehicles, and Automobiles with intelligent network Automobile manufacturing, battery technology, general direction 7 Automobile manufacturing technology, the content of As shown below.
related technology research in the field of lightweight concluded that an increase in weight to reduce the direct means of mileage. As a pure electric vehicle to reduce weight if 10kg, driving range can increase 2.5km, Professor Yang Yuansheng National Academy of Sciences said in an interview, also agree with thIs conclusion, and added to enhance the driving range of electric vehicles, in addition to strengthening the battery and drive system outside the body and the degree of weight reduction Is also inextricably linked, and the body weight of the most obvious feature Is the choice of materials. At present, the weight applied to the new energy vehicles, several materials are high strength steel, aluminum, magnesium alloy, Carbon fiber and the like.
icon: selecting lightweight materials
Next, small series making combing properties and applications of several lightweight material, for reference .
1, lightweight materials – high strength steel
applied to high-strength steel Automotive new energy depending on the strengthening mechanIsm can be divided into an ordinary high-strength steel (Conventional HSS) and advanced high strength steel (the AHSS), advanced high-strength steels better ductility, while meeting the process performance also have a higher potential for weight reduction.
icon: the case of high-strength steel yield strength
Currently, high-strength steel body international mainstream model accounts for the ratio has reached 70% or more, wherein the independent brands application of high-strength steel has reached 45%. It Is understood that the United States Is the most common high-strength steel country, the use of body proportion Is close to 50%, as high as 60-65% can be expected in the future, but the ultra-high-strength and advanced high-strength steels significantly behind, just 5 ratio currently used%, It Is expected there Will be three-fold improvement.
icon: high-strength steel body
Industry experts believe that the anti-crash properties, processing, and cost, high strength steel compared to aluminum, magnesium alloy having obvious advantages, can reduce vehicle mass and improve to meet the dual needs of collIsion safety performance, even from a cost and performance perspective, it Is to meet the lightweight body, the best material to improve crash safety.
2, lightweight material – Aluminum
only 1/3 the density of aluminum steel, heat conductivity higher than 3 times more iron. Most noteworthy Is that the aluminum and steel structure design optimization can achieve the second weight loss, weight loss effect direct 50% -100%. Research shows that, using 1 kg of aluminum Automobile Alternatively weight 2.25 kg steel weight loss ratio up to 125%, can reduce emIssions over the life of the 20 kg. Thus, by virtue of its high strength aluminum alloy, recyclable, corrosion resIstance, high-performance and low-density material of choice for Automotive weight reduction, the use of aluminum in Automobiles Will grow rapidly, aluminum Car entered a golden period.
The domestic Car prices on the application of aluminum alloy materials, new energy Will have to Tiqi Rui, the company introduced a new generation of pure electric mini-Car – a small ant (code eQ1), in the structure using “+ full spatial structure aluminum composite material outer cover,” the combination, good control body weight, reduce manufacturing costs, to achieve a better body weight.
icon: aluminum composite frame outer cover +
However, aluminum the same can not be underestimated lack of body, when the body Is damaged by the collIsion, aluminum alloy shaping higher degree of difficulty, once the improper operation, spare parts, they are likely to crack or fracture, damage aluminum parts after the general, if not the sheet metal process adjust, basically it must be completely replaced. In addition, the aluminum alloy requires a special process to weld. Therefore, all-aluminum body means that maintenance costs later could be higher.
Tesla pure electric vehicles as a global pioneer, and has already begun to explore on the road to lightweight vehicles. Body of its iconic model on the Model SIt uses a large amount of aluminum and aluminum alloys to achieve the link member and the steel member by a special welding technique.
icon: the MODEL 3 Tesla aluminum body
3, lightweight materials – magnesium alloy
Magnesium smaller density than even 1/3 light aluminum, an aluminum alloy which Is relatively high, thermal conductivity, specific strength (tensile strength to density ratio); in addition, the magnesium alloy good dimensional stability, easy recovery, good maU.S.bility, vibration damping property than it Is good.
shown: electric buses magnesium alloys
Silver Lung electric buses magnesium alloy Is also equipped with active equalization performance lithium-ion technology BMS System cell having high safety, high stability, fast charging, resIstance to decay and strong features, in conjunction with a magnesium alloy body and many other advantages, for the passengers more Carbon, environmentally friendly travel solutions simultaneously, better reliability, safety city power travel.
As we all know, the United States magnesium production accounted for about 75% of the world so that new energy vehicles to achieve lightweight body to bring the convenience. American Society of Automotive Engineering made a saving and lightweight road map, expected in the next 10 years, magnesium used in high-end Car can exceed 100 kg / per, in ordinary Cars can break above 20 kg / per.
At present, domestic companies prototype aluminum body, more experts believe that magnesium alloy body may become the mainstream of Automotive lightweight body materials.
4, lightweight materials – Carbon fiber
Carbon fiber Is excellent in mechanical properties, less than 1/4 the density of steel, the tensile strength Is 7-9 times that of steel, Is the only species above 2000 ℃ high temperature environment of an inert material strength Is not lowered.
According to a domestic consulting firm released a research report, the next few years U.S.’s demand for Carbon fiber Will enter a period of rapid growth, Is expected to reach 25,000 tons by 2020, domestic demand for Carbon fiber, an average annual growth rate of about 15.5%. The rIse in industrial demand Will be more prominent.
As one of the pioneers of lightweight vehicles, the BMW i3 and i8 use in large-scale production Car even more Carbon fiber repairer push the peak of the wave. 2015 launch of the sixth generation of the BMW 7 Series for the first time on the Carbon fiber composite materialMaterial combined with steel, aluminum and plastic, so that the generation of thIs system BIW 7 successful weight loss 40 kg.
Japan’s Teijin Group, a subsidiary of the successful development of a lightweight passenger Car roof, Car roof made of Carbon fiber reinforced plastic, aluminum as well as other lightweight materials, Will be applied in Toyota development of the world’s first mass-produced fuel cell buses SORA on.
illustrating: Toyota FCB SORA
In fact, the current price of the Carbon fibers 1500 and 1600 per kg, are brittle materials, once excessive force Will direct fracture, the basic damage beyond repair, and high manufacturing costs and recovery costs but also makes the application of the current main Carbon fiber Is also limited to high-end sports Cars, sport utility vehicles and sports Cars.
Summary: Presented by new materials, new technology and new design-driven revolution in the Automotive industry, it Will also be with the popularity of these models, thereby affecting the global Automotive industry, the pattern of deep-seated. Especially in the new energy Automobile triumph at thIs stage, it Is too large vehicle quality has become one of the obstacles restricting its development, the development of lightweight vehicles without delay. With the development of lightweight materials technology, it Will bring more possibilities for the development of new energy vehicles.