Materials Used for Vehicle Armour | |
Materials Used for Vehicle Armour
Introduction
Military vehicles are often armoured, such vehicles can be defined as Aircraft, Tanks and Ships.
Vehicles that are used in; Combat Operations, as transport in Warzones and by people who perceive they are under threat of attack are often armoured to stop bullets, grenades, IED’s and in the case of tanks, artillery rounds and missiles from penetrating the passenger space inside of the vehicle.
Discussion
Key mechanical property requirements of the material
Vehicles can be armoured with anything that improves the survivability of the passengers inside the vehicle. Vehicles are most often armoured with steel, Aluminium, titanium (is seldom used due to its expense), Uranium, Plastic, Bullet proof glass, Ceramic Armour, and Composite armour.
The armour needs to be hard and tough enough to withstand impacts from dense materials travelling at high speed.
The important failure mechanisms that must be considered in material selection.
The armour would most likely fail in fracture from Impact loadings and stress strain fracture caused by projectile impacts and explosive shockwaves.
Three commonly used materials for armouring vehicles and their composition and micro structure are;
1. Steel
Rolled homogenous armour
Steel used in this application must be hard yet tough enough to resist the shock caused by high velocity projectiles striking it, to produce steel with these characteristics, steel billets are hot rolled into plates, and the hot rolling lengthens the grain structure within the plate, this causes any impact stresses to be spread through the plate rather than to be focused in a small region.
To develop the toughness of the plates matrix tempering is required, once this occurs the microstructure comprises of martensite/bainite.
The plate is said to be homogenous because it is of consistent composition all the way through