Application of titanium alloy in automobile lightweight manufacturing

Titanium and titanium alloy have the characteristics of small density, excellent mechanical properties, good biocompatibility, corrosion resistance, high temperature resistance and low temperature toughness, and so on. They have been widely used in automobile manufacturing field.

Titanium alloy density is only 60% of steel, and the strength can reach 800MPa, and it still maintains good mechanical properties at 500 ℃, and welding and forming performance are good. It has been applied to the manufacture of racing car more than 20 years ago, greatly reducing the quality of racing engine and improving engine performance.
At present, titanium alloy parts used in automobile manufacturing are mainly distributed in automobile exhaust system, engine system, transmission and vibration damping system and body frame.

Exhaust system

The material of automobile exhaust system requires good mechanical properties at high temperature and corrosion resistance of S and Cl elements. Traditional exhaust valve components are made of stainless steel, but titanium alloy is found to be more suitable for exhaust valve materials in performance.
Titanium air return pipe used in the new Chevrolet Corvette z206 vehicle effectively avoids the pitting and weld corrosion problems on stainless steel pipes, improves the combustion efficiency and acceleration ability of fuel oil and shortens the braking distance.
Timet, the largest titanium manufacturer in the United States, has been committed to the research and development of titanium alloy exhaust system. Several Japanese companies have also carried out relevant research and development. At present, Fuji Heavy Industry Co., Ltd. has limited production of 440 sets of titanium alloy automobile exhaust pipes.

Engine system

Automobile engine system is the most used part in automobile field. Titanium alloy is mainly used in engine system, such as valve, connecting rod, crankshaft, valve seat and so on.
Honda Motor Company of Japan used forged titanium link in NSX V-6 engine, titanium valve spring seat was used in high capacity and four cylinder engine manufactured by Mitsubishi Motor Company, and titanium link was also used in Porsche.

Valve

Titanium alloy valve has been studied in the United States and Japan. At present, the United States generally uses Ti-6Al-4V alloy to make the inlet valve, and ti-6al-2sn-4zr-2m o alloy to make exhaust valve; while Toyota company of Japan uses ti-6al-4v/ti B alloy to prepare the inlet valve, and ti-al-zr-sn-mo-nb-si/ti B alloy is used to prepare the exhaust valve. These titanium alloys have good mechanical properties at high temperature, oxidation resistance and creep resistance, which effectively improve the engine performance and improve the vehicle speed.

Valve seat

Titanium alloy valve seat has been widely used in racing and sports vehicles. More than 250000 sets are produced every year. It is mainly made of Ti-6Al-4V or ti-5al-2cr-1fe alloy. Because the valve seat shape is relatively simple, it is not required in mechanical processing, and does not need special surface treatment, and the cost is relatively cheap, and the effect is obvious in vehicle weight reduction.

Connecting rod

The use of titanium alloy connecting rod can effectively reduce the quality of the engine and improve the performance of the automobile. At present, the main preparation materials are Ti-6Al-4V alloy. Datong Co., Ltd. is currently developing a two-phase titanium alloy ti-3al-2v-0.2si-0.47ce-0.27la. The alloy has good cutting property and excellent mechanical properties, fatigue performance and corrosion resistance. It is expected to be used in the connecting rod parts of engine with rapid acceleration and rapid deceleration.

Crankshaft

Although titanium alloy crankshaft has not been widely used at present, the Ti-3Al-2.5V alloy specially developed in Japan has been verified on honda racing car. At the same time, the engine speed is improved by 700r/min while the quality is effectively reduced, which proves the advantages of titanium alloy crankshaft. At the same time, Japan has been trial producing ti-5al-2cr-fe alloy crankshaft, and it is expected that titanium alloy will be widely used in crankshaft parts.

Vibration damping system

The core component of the automobile vibration damping suspension system is the suspension spring. Compared with the steel used in automobile spring, titanium alloy has higher specific strength and lower shear modulus, and has higher fatigue resistance, which is more suitable for manufacturing automobile shock absorber spring. Because the deflection and number of rings of spring are proportional to the shear modulus of material, titanium alloy spring needs less cycles than steel spring when the same spring reaction is achieved, which effectively reduces the spring quality and saves space.
At the same time, the resonance frequency and service life of the spring can be improved effectively. At present, most of the titanium alloy springs are made of single phase β titanium alloy. Volkswagen has used Lupo FSI titanium alloy gear springs for about 3500 vehicles.

Frame of car body

In terms of the frame parts of the car body, the titanium alloy has a high specific strength, low density and good corrosion resistance, which indicates that it is a good material for the preparation of the car body frame. At present, there are already automobile companies using titanium alloy on the gear bracket, brake caliper piston and other parts. In transmission parts, Japan is developing a high spinning forming technology for titanium alloy shell. Compared with steel shell, titanium alloy shell can reduce the impact of flywheel better and buffer effect better.
In addition, titanium alloy is also used in automobile fasteners and other parts. With the development of titanium alloy preparation technology and automobile industry, titanium alloy will be more applied in automobile parts.

Significance of titanium alloy in automobile lightweight

The results of the calculation by foreign research institutions show that when the quality of vehicle preparation decreases by 10%, the fuel consumption can be reduced by 6% – 8%. It is also shown that the average fuel per liter can travel 0.43km per litre of fuel per weight loss of 91kg. Therefore, with the continuous development of China’s economy and the increasing of car ownership, automobile lightweight has become one of the important ways to reduce energy consumption and reduce air pollution.
Titanium and titanium alloy materials have been widely used in automobile parts because of their excellent physical and chemical properties. The use of titanium not only effectively improves the performance and safety coefficient of the vehicle, but also plays an important role in the light weight of the vehicle, effectively reduces the quality of the vehicle preparation and reduces the fuel consumption.
Compared with traditional stainless steel system, the exhaust system of automobile adopts titanium tailpipe and air return pipe assembly, which can reduce weight by about 8.2kg. The quality of the engine can be reduced effectively by replacing traditional steel and cast iron with titanium alloy in the parts of engine such as air valve and connecting rod.
According to the research of Japanese automobile industry, the effect of using about 0.8kg titanium material parts for automobile power valve is equivalent to 20kg steel parts; each titanium valve seat can reduce the mass of about 10g compared with steel valve seat; connecting rod and crankshaft are used in titanium alloy, which is the most effective way to reduce the quality of engine.
On the vibration damping system, each titanium alloy spring can reduce the mass by more than 60% compared with the steel spring. It is calculated by four suspension springs of each vehicle. After replacing with titanium alloy spring, each vehicle can lose weight by 9-13.6kg. In addition, the mass of titanium alloy muffler is only 5-6kg, which is 40% lighter than that of stainless steel muffler.
Taking ordinary medium-sized car as an example, if the existing titanium alloy automobile parts are replaced with traditional parts, the quality of the vehicle preparation will be reduced from about 1500kg to about 1000kg, with a weight reduction rate of 30%, and the comprehensive fuel consumption can be reduced by more than 20%. This will greatly reduce the fuel consumption in the world and effectively alleviate the energy shortage and environmental pollution.
The above data show that the use of titanium alloy has obvious effect on automobile lightweight. In modern automobile industry, the application technology of titanium and titanium alloy in automobile parts should be developed constantly to improve the application proportion of titanium alloy in automobile.
At present, the application of titanium alloy in China’s automobile industry is still in the trial stage. The main problems are that the cost of titanium alloy is too high, and the parts are not easy to process.
Therefore, the main task in the future should be to reduce the price of titanium alloy parts by developing cheap titanium alloy materials, reducing the production cost of titanium alloy raw materials, and improving the processing efficiency of titanium alloy parts.
Foreign experience shows that only the automobile design and manufacture side and titanium alloy development party can provide better titanium alloy materials for the automobile.

I believe that with the development of research and development, titanium and titanium alloy will play an increasingly important role in the modern automobile industry in China, and promote the continuous development of the automobile industry.

Source: China Titanium Flanges Manufacturer – Yaang Pipe Industry Co., Limited (www.steeljrv.com)

(Yaang Pipe Industry is a leading manufacturer and supplier of nickel alloy and stainless steel products, including Super Duplex Stainless Steel Flanges, Stainless Steel Flanges, Stainless Steel Pipe Fittings, Stainless Steel Pipe. Yaang products are widely used in Shipbuilding, Nuclear power, Marine engineering, Petroleum, Chemical, Mining, Sewage treatment, Natural gas and Pressure vessels and other industries.)

If you want to have more information about the article or you want to share your opinion with us, contact us at [email protected]

Please notice that you might be interested in the other technical articles we’ve published:

• Why is titanium alloy a kind of difficult to machine material
• Analysis of corrosion resistance of titanium pipe and titanium alloy pipe in chemical industry, petroleum industry and metallurgy industry
• Development and application of titanium welded pipe in China
• What is titanium pipe
• Difference between titanium welded pipe and titanium seamless pipe and feasibility analysis of alternative field
• New marine material: titanium alloy
• Analysis of forging process properties of common titanium alloys