Hey Guys,
Please remember that English is only my second language. I have a few questions and already tried to find answers on other forums but without success.

Shaped charge warheads are complicated technology especially when it comes to deatil. But for now, let's skip things like explosives, liner shape, ignition systems, wave shaper, fluid dynamics etc.

It is about state of the art liner materials. First some pictures and links to documents. Penetration depths of 12xCD are possible with precision shaped charges.

https://www.semanticscholar.org/paper/PERFORMANCES-AND-BEHAVIOUR-OF-WCu-PSEUDO-ALLOY-WITH-Voumard-Roduner/391989157933eb38131fd44be2a661c2815f24f8




To achieve penetration depths of 12CD (12xCD= 12 times the charge diameter) molybdenum and W-cu liners are used but W-cu liners are limited to very large stand off. This is older technology, now it's 2023 and I found this article. Well written and worth reading.

https://www.edrmagazine.eu/saab-further-develops-its-knowledge-in-warhead-technology


Saab Bofors Dynamics continues to develop the technology to make a penetration depth of 15CD possible.
The question is what is liner material???
Pure copper does not do the trick.

Furthermore, I would like to add based on research and technology that probably even 16-17CD penetration is possible.

For those who have read the article, let's say just for example you can achieve a penetration depth of 13CD (13xCD) with LX14 explosive and molybdenum liner. That would mean if the charge has a diameter of 100mm, 13CD would mean 1300mm penetration. The target is mostly RHA.

So now get rid of insensitive explosives like LX14,HMX etc. CL20 is much more effective.

I quote
"The photo above makes clear that CL-20 is considerably more powerful than HMX, demonstrating about 40 percent deeper penetration in steel blocks"
(https://newatlas.com/cl-20-high-power-military-explosive/24059/


Now let's relate the 40% more penetration to the above mentioned 13CD penetration depth of the molybendän LX14 shaped charge. 13CD+40%= 18.2CD depth of penetration. Even with a smaller number, if you only add 20% to the 13CD depth of penetration, the would be 15.6CD.

Here comes the next magic trick
Penetration of a shaped charge jet can be enhanced by at least 40 % by imploding a liner in a high pressure, light gas atmosphere. So if you calculate 40% on top to the 15.6CD depth of penetration.... Calculate the math for yourself. You end up with a really evil penetration fantasy.

I would like to add 2 more things.
Lawrence Livermore successfully tested a shaped charge that penetrated 3.4 meters of high-strength armor steel, in 1997. It was a molybdenum liner.

And by the way with so-called cavity charges and hypervelocity shaped charges, jet tip velocities up to 25000 meters per second were achieved.

Does anyone know if molybdenum is still the state of the art or if there are alloys that are even better than W-Cu and molybdenum? 

APFSDST said:

The question is what is liner material???

As if this information is available to the public.

APFSDST said:

Pure copper does not do the trick.

Pure copper is not used for HEAT liners anymore since the '50 or '60.

APFSDST said:

You end up with a really evil penetration fantasy.

Yes that is exactly the point. A fantasy.
The penetration rating you look at is measured against RHA. Which is theoretical. Its just a standardised benchmark. Just because a warhead theoretically penetrates 1000 mm RHA doesn't mean it can penetrate the main armor module of a current modern MBT. Since these, and allmost all other AFV, don't use RHA.
A single stage shaped charge can be easily defeated even by old ERA designs. So they are not state of the art anymore.

Again you also need to take the behind armor effect into concideration. The highly focussed extrem penetration shaped charges usually have very poor behind armor effect.
 

APFSDST said:

Does anyone know if molybdenum is still the state of the art or if there are alloys that are even better than W-Cu and molybdenum? 

Have you even bothered looking at the periodic table of elements?
Because if you had, you might have noticed why Mo, or better an Mo alloy, is used in some cases.
The current standard are still W alloys BTW. At least for modern munitions. Copper based alloys are used for cheap munitions or by less developed manufacturers. There has been some experementation and use of DU as well.
More details likely require a security clearance.

The evil penetration fantasy was meant as a joke... ERA (explosive reactive armor) is nowadays only a bad joke. The new tandem warheads overcome all generations of explosive reactive armor. For example, the Akeron MP warhead.
I have done extensive research on this subject.

DU liner is not even close to being as good as some people may think. Desirable properties for liner materials are high density, high ductility, high melting point and important sound velocity of the material (sound velocity in solids/bulk sound velocity). Bulk sound velocities of the liner materials define the maximum possible jet tip velocities. The bulk sound velocity of DU is way too low.
Cu=3900 m/s, DU= around 2300 m/s, Mo=6000 m/s. The velocities are approximations, as they vary slightly depending on the source of information.

The strength of the material is negligible at hypersonic velocities. Everything behaves almost like liquid and fluid dynamics become important. One of the reasons why hard brittle liner does not work so well. The break off time of the jet is also very important. That is why ductile materials work better as liners than brittle ones such as pure tungsten.

Information is sometimes hard to find but there is no information block, at least not in Austria and Germany. I contacted TDW warhead systems some time ago and asked politely which liner material reaches penetration depths of 12CD or more.
The answer was not very comprehensive, I was not told any specific alloy or exact details. However, I was told for penetration depths above 10CD molybdenum, all the way. I have also tried to contact Saab Bofors Dynamics switzerland but with even less success. The final point I still want to know what alloy Saab has in mind to achieve penetration depths of 15CD in the future as stated in the article.

Also, I stand by my point. In an optimal scenario. A high precision manufactured shaped charge, a Mo or Mo alloy liner, a Bosster charge, a wave shaper, etc. CL20
explosive main charge ignited in a high pressure, light gas atmosphere can reach penetration depths above 15 CD. 

There's likely bulk structures materials and new manufacturing methods involved, potentially coupled with 3d printed exotic explosive charges 

Probably yes. However, let's take a look at the picture from EDR Magazine article. I read Lx14, AL, MOJET (the simulation) My best guess, MOJET= Molybdenum jet.

https://www.edrmagazine.eu/saab-further-develops-its-knowledge-in-warhead-technology

schnuersi said:

Have you even bothered looking at the periodic table of elements? Because if you had, you might have noticed why Mo, or better an Mo alloy, is used in some cases. The current standard are still W alloys BTW. At least for modern munitions. Copper based alloys are used for cheap munitions or by less developed manufacturers. There has been some experementation and use of DU as well. More details likely require a security clearance.

Once again, I would like to intensively address the topic and also your post. The reason is simply that I can't get the questions out of my mind. Of course, I have taken a look at the table of periodic elements but it doesn't make me much smarter to keep guessing.

Liner material, the highest density would be osmium, iridium and rhenium but they are brittle and not ductile.

The highest bulk sound velocity have materials like byrelium and carbon but they are not dense enough and also brittle.

Du has a very low bulk sound velocity. So I'm pretty much going in circles. Mo has good properties. Density higher than 10 g/cm , bulk sound velocity of 6000m/s and the transition from brittle to ductile is given at the detonation of the shaped charge. I have to say, the higher the pressure and the higher the heat during an explosion, each metal becomes more ductile.
There are so many different factors in choosing the liner materil for a shaped charge.... not to mention I am not a scientist.

I could accept molybdenum as the answer for perfect lining material, but no, that would be too easy, and molybdenum liners were around in 1997. Technology does not stand still, and I strongly suspect that there are far better things than Mo, W and Cu liners.

You pointed out to me that some information is not publicly available. I understand that, and that's why I'm not asking about design, ignition systems, etc.
I am simply asking which liner can achieve the highest penetration depth in relation, diamter of the charge to depth of penetration. (Penetration depth measured in CD)

Do you or anyone here know more about this? Or what kind of Mo alloys are used?


Furthermore, i would like to know what lining material is used in the Spike NLOS 6th Generation (the HEAT warhead).
Knowing what liner material is used in the new Brimstone 3 anti tank missile would also be interesting.