Introduction

Tungsten copper military 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.

Principle

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.

Comparison

Generally speaking, 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 copper military throat insert to ensure the stability of working.