Tungsten Copper Nose Cone

Tungsten copper nose cone at the front of a rocket or missile, when it enters the atmosphere at supersonic speed, will have a strong head detached bow shock. It can protect the payload and endure the large temperature difference and high-speed particle erosion at the same time.

A rocket includes a high thin cylinder, made by sheet metal. The cylinder stores the rocket engine's fuel and refueling tank inside, and rocket propulsion engine is provided at the bottom of the cylinder. In the upper part of the cylinder is fitted with a hollow cone streamlined, connected to the base of the cone cylinder, cone tip upwards. This shape of the cone of the rocket exposed to air cross section of minimum cross-sectional area is reduced to reduce the energy required for rocket discharging air consumption. Generally, the payload of manned spacecraft is placed in the top of the rocket nose cone. It is called as payload fairing cone in space technology, which plays an important role in protecting the payload after rocket ignition and prevent the rocket from destroyed by the enhanced wind of rocket accelerating.

The ablation mainly includes thermal chemical ablation and mechanical erosion. Ablative heat characteristic is the use of short, tungsten, copper nose cone is a typical heat sink material, which is adjusted by the material properties of its own, is evaporated and turned away most of the copper in the heat, so it can keep the allowed temperature inside the craft. In addition, the ablation mechanism can be divided into sublimation, melting and charring, which has a cross-phase relationship of the triple point, at high temperature and pressure, carbon homogeneous melting and evaporation occurs interaction phenomenon exceeds the triple point.

Tungsten Copper Military Contact

Tungsten copper military contact has excellent arc ablation resistance and welding resistance, and it plays an important role in military high-load, high-temperature, high –pressure breaker, segment contacts and conductors.Tungsten copper military contact is the core component of high voltage circuit breaker, isolating switch. Especially the quality of the contact has a direct impact on the quality and the service life of military high-voltage equipment. Tungsten copper contacts has excellent resistance to arc burning and welding resistance, arc breaking performance, good thermal conductivity, thermal expansion of small, does not soften at high temperature, high strength, high density, high hardness. Above 3000 ℃, the copper is liquefied evaporated absorbs heat, reduces the surface temperature of the material. Thus, tungsten copper contact is the best choice for military high-pressure arc.

Generally, it is combined mixed powder sintering with infiltration. But with the development of military-related technology, the performance requirements of the contact material have become stricter. Contact materials will not only have a higher welding resistance, but also need to have a sufficiently high arc resistance compressive strength, low off current as much as possible and very low gas content. Conventional preparation tungsten copper material has low material utilization and the performance is difficult to meet the requirements of military applications. Therefore, in order to achieve military contact material performance requirements and extend the life of using, appears many advanced production technology, such as fiber-reinforced method, isostatic pressing-dipping, rolling sintering process, ion implantation, arc melting method and so on.

Tungsten Copper Military Nozzle

Tungsten copper military nozzle is kind of device accelerating air by changing the shape of inner wall, which has high hardness, high strength, high softening temperature, low coefficient of thermal expansion and excellent arc breaking performance. So it plays an important role in military high temperature and spiral accelerated pipeline. Tungsten copper military nozzle has many types, according to the specific performance of aircraft and engine, it can be specifically divided into fixed or adjustable convergent nozzle, convergent-diffused nozzle, eject nozzle and adjustable nozzle, etc.

Convergent nozzle: sectional area of the flow direction gradually reducing, in large mach flying, incomplete expansion will cause great loss of thrust;
Convergent-diffused nozzle: also known as Laval nozzle, is a kind of nozzle cross-sectional area diffuses after convergent, mainly used in supersonic fighter, the critical area and exit area are required to fly with the state regulation;
Eject nozzle: consists of adjustable convergent main nozzle and a fixed or adjustable ejector. It is light and has simple structure, can maintain good performance over a wide range of flight, it has been widely used in many high performance aircraft;
Adjustable nozzle: mainly used for high-speed flight after-burning turbojet aircraft or military after-burning turbofan engine. Easy to adjust nozzle area ratio, may vary with flight conditions, and often in a fully expanded state. Structure type balanced rod, folding, folding petal sleeve cone and so on.

In addition, tungsten copper military nozzle expansion accelerated as the airflow at a high speed jet and counter productive outward thrust. Most high-speed fighter uses adjustable nozzle and adjustable convergence-diffusion nozzle or ejector nozzle; common fixed convergent rocket engine-diffusion nozzle; vertical or short takeoff and landing aircraft using commutation nozzle. In addition, In the ASRM (Advanced Solid Rocket Motor) the front nozzle is also used tungsten copper material.

Tungsten Copper Throat Insert

Tungsten copper throat insert is lining material of solid rocket motor nozzle, and its high temperature performance and ablation resistance directly affects the thrust and efficiency of the engine. Solid rocket motor nozzle by controlling the expansion of the combustion chamber exhaust gas generated energy is efficiently converted to kinetic energy, so as to provide the required power for the aircraft. The throat insert is located in the nozzle throat, and its main role is to limit the throat area due to erosion produced by increasing phenomenon, caused by the thrust decreases. When the engine is working, throat insert often require direct heating from room temperature to greater than 2000 ℃, resulting in significant temperature gradient and thermal stress, which is the main reason for failure of the crack and working throat lining material appears. In addition, for this type of high-performance rocket engines commonly used metal powders (such as Al) as propellants combustion at high temperature of about 3000 ℃ high burning rate entrained flow of solid particles or liquid droplets Al2O3 severe erosion. If lining severe erosion is difficult to ensure a stable aerodynamic shape even fragmentation occurs, it will directly affect the thrust and efficiency of the engine.

Generally speaking, compared with other materials, tungsten copper has better performance in many aspects. Throat lining material for the solid rocket motor comprising refractory metal, graphite, carbon and carbon-based composite materials, reinforced plastics, ceramic matrix composite materials. Throat heat transfer can be divided into three stages: 1. engine ignition instant impact heating; 2. ablation steady when working; 3. flameout cooling. Tungsten copper material not only has high hardness, high density, high strength, high melting point, low thermal expansion coefficient and excellent wear and corrosion resistance, also has good ductility and electrical and thermal conductivity. And since the large difference of two kinds of metals, at higher than the melting point of copper, copper is evaporated away to leave most of the heat of the hard phase tungsten throat insert to ensure the stability of working.

Tungsten Copper Gas Vane

As a special wing in rocket jet, tungsten copper gas vane represents the thrust vector controlling technology. And it is indispensable in AAM active duty and in studying. Therefore, it has many strict design requirements as follow:
1. It should have a constant value close enough to lift the gradient to meet the maximum lift control requirements;
2. Differential gas vane should meet the requirements of rolling control;
3. Ensure small resistance to reduce the loss of engine thrust;
4. Rudder hinge moment and change the entire duration of the work to be relatively small in order to reduce the power requirements of the steering gear;
5. Gas vane small as far as possible, but should meet the strength and rigidity requirement. And reasonable location is convenient for attached parts designing and installation;
6. It can not produce mechanical interference when gas vane deflected to the maximum angle.

Based on the ablation mechanism, it can specifically divided into:
1. Effect of particle erosion: A large amount of high energy solid particles in gas stream impact the surface of gas vane intensely, which partial surface reach high temperatures in a short time and accelerate the material ablation. Besides, the surface roughness increases will lead to uneven distribution of the flow field to form a vortex, and lead to the accumulation of localized heat;
2. Mechanical erosion effects: the presence of a thermal expansion coefficient difference between the substrate materials caused by thermal stress generated when it exceeds the combined strength of the gas flow at supersonic peeling effect occurs.

Tungsten Copper Military Sheet

Tungsten copper military sheet is also called as heat sink plate, which has high thermal conductivity and excellent hermeticity. It has a broad prospect in RF, microwave, high power diode and other military fields. There are some common grades of tungsten copper military sheet used: 

Grade	Proportion（wt%）	Mass Density（g/cm3）	Relative Density（%T.D）	CTE （ppm/K）	Thermal Conductivity（W/m·K）
W90Cu	90±1	17.0	≥99	5.6-6.5	180-190
W85Cu	85±1	16.3	≥99	6.3-7.0	190-200
W80Cu	80±1	15.4	≥99	7.6-9.1	200-220

Except high-temperature liquid phase sintering, infiltration, activated liquid phase sintering, mechanical alloying and co-reduction, tungsten copper composite materials can be also manufactured by hot hydrostatic extrusion, electrolysis, plasma spraying, rapid directional solidification and sol-gel method.

Hot hydrostatic extrusion: On completion of four-post hydraulic machine, mold using three sets of combination of prestressed die, while using the outer heating coil and ceramic heating tube mold preheating;

Electrolysis: Electrolysis adopted in accordance with a certain proportion of NaCl, KCl, Na2WO4 and CuO4 mixed solution as graphite electrodes, continuous electrolysis 3h. The electrolysis products out into distilled water after boiling, by adding an appropriate amount of NaOH solution soak give the final product after filtration and drying;

Plasma Spraying: to strengthen the material surface and the new multi-purpose precision spraying surface modification technology in the field of tungsten copper electronic packaging material has broad application prospects;

Rapid directional solidification: produce specific temperature gradient between solidifying metal and non-metal solidification, and make alloys in a wide range of solubility solidification, high solid phase alloying elements to obtain content and grain refinement significantly fewer microscopic segregation;

Sol-gel method: metal alkoxides and their compounds as raw materials, under certain conditions hydrolysis medium and catalyst - the polycondensation reaction solution into a gel, and then by drying and heat treatment to obtain synthetic materials.