The problem with Burlington armor, or rather Burlington program is that not single armor design was developed under that program, but there were at least several different Burlington armors. One of the reports said even about Burlington with build-in explosive reactive armor.
We can assume that when British designers shared data about Burlington with other allied countries, designers in these countries started to alter Burlington armor design to better meet requirements of each NATO army.
We can assume that indeed all NATO's countries that are tank designers/manufacturers and countries from outside NATO that are or were close allies. Recived the Burlington armor data, and altered it's design. So we can assume that actually majority if not all, western composite armors, are in fact a "bastard" childs of Burlington armor program.
Of course reality might be different but, many sources, official and non official and clues like photos of damaged M1 turret side composite armor, damaged Merkava Mk4 composite armor, some concept drawings etc. Seems to support this theory.
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As for M1 series DU armor. Well the problematic issue with this is that we know only about DU being used as armor component but... the key here to understand the role of DU in armor is that, it is an alloy, which means it can't be treated as most DU alloys known to civilians. And also fact that DU alloy elements are encased in steel, and here the best thing, what steel it is?
We should assume that the best way to efficently use high density of DU is to encase it in SHS or HHS steel. Thanks to this we achieve interesting combination of very dense heavy metal that is not very hard and thus more... elastic, and additionally to this, a SHS or HHS steel to gain high hardness benefit.
It is possible that in newer 2nd or 3rd (and perhaps even 4th because of recent reported armor upgrades for M1 series) generation of this armor, might use even THS steel, or ESR steel.
This in my opinion is the biggest problem when most people talk about composite armors, they focuse on a single material used, like ceramics or DU, as armor element that is most reponsible for armor protection characteristics, while in reality, each element and every possible combination of materials used, sums in armor protection characteristics.
This is why simple RHAe estimations of modern MBT's protection seems to be inadequate, and that simple mathematics are also not reliable way to approximetly estimate vehicle protection without the complete data.
Another problem is that these modern, western composite armors, seems to be some sort of non explosive/non energetic reactive armor, by using sort of reactive materials like rubber or for example poliurethane.
It seems that Russian and Ukrainians in their newest tanks, also choose the same way, however there is one important difference. Due to weight and size restriction, they were unable to use a composite armor with high volume of composite insert per whole armor thickness. This is why they are, more or less forced to use explosive reactive armor as not addon but integral protection of their MBT's.
Of course it is only my opinion based on several years of research, someone might agree or not.
I would actually pick the t-90. Don't really know the stats but I know it has a higher top speed and that it needed for a great tank. Also it is made by RUSSIANS !!!!
It also depends what T-90 You have in mind. The original T-90 or Object 188 is nothing more than T-72B (Object 184) on steroids, the actually manufactured variant for Russian armed forces is T-90A or Object 188A1/A2 with a slightly improved hull and completely new turret derived from different development, the Object 187 that was highly advanced tank that had been designed by UVZ UKBTM the same design bureau that designed T-72 and T-90 series.
And there is of course the T-90AM/SM or Object 188M but it is still only a technology demonstrator.
