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40mm grenade
- Thread starter SG500
- Start date
Thanks Lee.
The copper cone is a shaped charge, when the thing goes pop a jet of molten metal squirts out the front at high speed punching a hole in whatever is in the way.
Dave.
Just had a fuller explanation from US subs (Thanks) as follows:
"The liner has a slightly different function, though the end result is the same. The copper cone actually provides resistance against the explosive wave as it moves forward. The wave then pushes the cone inward, collapsing it.
As the now inward moving wave impacts itself at the center, a point of forward moving extreme high pressure is created. This is what actually causes the penetration, not burning, nor the copper slug, which follows along behind the point of high pressure. Under such high pressure the steel acts much more like a liquid, and is simply pushed out of the way, much like when on a warm winter day a child stomps in the melted snow (slush) and makes a giant footprint.
In fact, you can occasionally find the slug (the remnants of the copper cone end up in a typical shape, slightly similar to a teardrop - typical for nearly all sizes of shaped charge, known as the slug) stuck in the outer edge of the hole, or on the ground in front of the target. This would not be possible if the slug were responsible for creating the penetration"
Chris 42 RQ
Well-Known Member
Non Hazardous waste !
No it does not have to be Copper (Cu) as many other metals have been tried, however Copper usually comes out best for machineability ease of forming etc and of course cost, being a relatively common element it is probably the most cost effective solution with very little in the way of pollution or hazardous waste after use.
Heavy metals are apparently pretty good as the shaped charge cone but do leave potentially lethal dust/particles around that cause problems.
No it does not have to be Copper (Cu) as many other metals have been tried, however Copper usually comes out best for machineability ease of forming etc and of course cost, being a relatively common element it is probably the most cost effective solution with very little in the way of pollution or hazardous waste after use.
Heavy metals are apparently pretty good as the shaped charge cone but do leave potentially lethal dust/particles around that cause problems.
Copper is usually used for shaped charge liners because it is relatively inexpensive, easy to work with to make the liner and more importantly is very ductile so it collapses easily without breaking apart. That ensures a better formation of the penetrating jet and follow through slug. Just about every type of material you can think of has been used either in fielded ordnance or experimentally over the years. Steel has been used, but it tends to be more of a break-up problem. Depleted uranium, glass, aluminum, titanium and many other exotic metals have been used. Actually, if you do not plan on penetrating large amounts of metal, you don't even need a liner. If you create a conical cavity in an explosive charge a jet will still form that will penetrate. A typical shaped charge jet travels between 5 to 11 km/s and represents about 15% of the original liner mass. Most of the remaining liner mass makes up the slug that travels at a slower 1 km/s. Distance is the enemy of the jet because travel through air breaks it up and degrades the penetration. This is why shaped charge ordnance has a built-in "stand-off" which is close to the optimum performance range of the jet. Credit is generally given to Charles Munroe in the 1885 to 1900 timeframe for the shaped charge concept, which is why Americans called it the Munroe Effect, but that is actually not the case. As early as 1792, F.X. Von Baader published a design for a mining charge that had a conical or mushroom shaped cavity in the forward end. In 1885, Gustav Bloem of Prussia was issued a US patent for a primer with a hemispherical cavity in the base to concentrate the effects of the primer charge in an axial direction. Munroe's designs included metal liners for the first practical application. A German, Egon von Neumann in 1910-11 added a metal liner to a shaped charge, hence in Europe the effect is often called the Neumann Effect. I don't think either man ever got a patent though, but I have not researched that for sure.