Preliminary study on the application of titanium and titanium alloy in the chassis of amphibious special vehicles

In order to improve the comprehensive performance and environmental adaptability of military equipment and meet the needs of diversified amphibious missions, the company jointly developed a type of amphibious special vehicle; For the first time, titanium and titanium alloy AMS 4911 sheet were used to replace the traditional high-strength steel plate as the main material of the chassis frame and body of the special vehicle, and the performance requirements of body protection, structural lightweight, and seawater corrosion resistance were met. Explore the titanium and titanium alloy AMS 4928 Titanium Bar large structural parts welding, machining, painting and other production process methods, so that the company has the corresponding parts of the whole process of self-manufacturing capabilities, and for the company's special vehicle chassis diversified development and market development provides technical support, while improving the environmental adaptability of military equipment and safeguarding China's maritime rights and interests is of great significance.

With the continuous improvement of China's coastal defense requirements, improving the environmental adaptability of military equipment has become an important aspect of our military equipment research. The company jointly developed a new amphibious vehicle special vehicle chassis, as one of the advanced weapons and equipment, can meet the needs of diversified amphibious missions, can improve the vehicle in the ocean, land, beach and other special environment adaptability, will play a huge role in safeguarding the national maritime rights and interests.

The birth of each advanced equipment is inseparable from the application of new materials, and the common material of the existing amphibious vehicle chassis is high-strength steel, corrosion resistance needs to be improved, and lightweight cannot be achieved, reducing the carrying capacity of the vehicle, shortening the service life, restricting the development of amphibious vehicles. Titanium and titanium alloy AMS 4911 sheet with its excellent comprehensive performance into people's vision, and is a light weight, high strength, good corrosion resistance, high and low temperature adaptation wide, high elasticity and other excellent performance of the material, applied to the automobile can play a weight reduction, energy saving, shock absorption, corrosion resistance, pollution reduction, life extension role, improve car safety and comfort, is to achieve automotive lightweight thinking material.

In order to realize the design concept of lightweight and corrosion resistance, and meet the requirements of vehicle body protection, stiffness and strength performance, the company jointly developed the new amphibious special vehicle as shown in Figure 1. The frame, body and key components of the vehicle are made of titanium and titanium alloy Aerospace Application Titanium.

In order to improve the comprehensive performance of special vehicles, titanium and titanium alloy instead of high-strength steel and protective armor steel in the vehicle can achieve the goal of vehicle lightweight, such as the United States used TC4 titanium alloy for armor plates to replace part of the steel, so that the weight of the armor itself reduced by about 40%, and achieved good results; The hatch of the US Army M2A2 Bradley infantry fighting vehicle has reduced its mass by 35% after using titanium alloy instead of forged aluminum alloy, and greatly improved its bulletproof capability. The front of the Russian T95 tank gun uses all-titanium alloy modular armor with high strength and good toughness, which makes its resistance ability reach the resistance ability of 1500 mm thick armor plate.

According to the requirements of amphibious special vehicle body protection class, the body must have certain bulletproof ability. According to GJB 59.18-1988 "Armored Vehicle test procedures armor plate anti-bullet performance test", it can meet the requirements of type 53 7.62 mm caliber ordinary steel core bullet 100 m penetration, that is, to achieve the corresponding bulletproof ability, with bullet-proof steel plate Domax protect500, The minimum thickness of bullet-proof aluminum alloy 7B52-T6 and high-strength titanium alloy HST2425 is 5, 18, 7 mm, respectively. Compared with steel and aluminum alloy, the mass of titanium alloy per unit protective area is about 20% smaller than that of steel, and about 35% smaller than that of aluminum alloy, and has good seawater corrosion resistance, strength and toughness are the same as that of steel. Therefore, the selection of titanium alloy HST2425 as the body bulletproof material, on the basis of meeting the requirements of bulletproof, and at the same time has lightweight, salt spray resistance and seawater corrosion resistance, effectively improve the vehicle carrying capacity and Marine environment adaptability.

The application of titanium and titanium alloy on the frame

The frame, as the substrate of the amphibious vehicle, is the core of the safety of the entire special vehicle, and most of the components and total Chengdu are fixed through the frame. As a vehicle skeleton, the frame plays an important role in supporting and connecting various parts of the car and bearing various loads from inside and outside the car. The chassis frame of the company's special cars mainly uses high-strength steel plate as the base material. In order to further improve the mobility, transportation and carrying capacity of amphibious vehicles, under the premise of not reducing the comprehensive mechanical properties, the chassis frame of this model is made of titanium alloy material, which can reduce the weight by more than 30% compared with the use of high-strength steel plate, so as to achieve the design purpose of lightweight. At the same time, it solves the corrosion problem of amphibious combat equipment in the Marine environment, effectively prolonging the service life of the equipment, and has the characteristics of high and low temperature mechanical properties and stability, which can meet the needs of diversified amphibious missions. The effect diagram of the amphibious vehicle frame is shown in Figure 3. The frame is mainly welded by longitudinal beam, beam, suspension support, track support, spray pump support and other structures.

The application of titanium and titanium alloy in parts

Important components of amphibious vehicles, such as transverse tie rod, suspension, swing arm, connection pin, etc., are shown in Figure 4. They are required to have good seawater corrosion resistance in the operating environment. TC4 / TC6 Grade 5 ASTM B 348 titanium alloy is an ideal material for the amphibious vehicle due to its excellent comprehensive mechanical properties and corrosion resistance. It also improves its fatigue resistance; The smaller its own mass, the smaller its oscillation energy consumption, noise, vibration, the vehicle fuel consumption is reduced, and the performance is improved, while the fatigue resistance and its good seawater corrosion resistance mean that the service life is extended, and the quality of the car is effectively improved.