Composite armour: Difference between revisions

{{Refimprove|date=September 2009}}

[[File:Soviet T-64.JPEG|thumb|250px|The Soviet [[T-64]] was the first mass-produced tank with composite armor]]

[[File:Leclerc-openphotonet PICT5993.JPG|thumb|250px|The [[Leclerc tank]] is said{{by whom|date=November 2021}} to be equipped with NERA (Non-explosive reactive armour)]]

[[File:Leopard 2 A5 der Bundeswehr.jpg|thumb|250px|Depending on the operating state, the [[Leopard 2]] has various extended armor elements such as bomb protection for the top, cage armor, extended mine protection (A6M) or additional armor in the form of composite armor [[MEXAS]] or [[Advanced Modular Armor Protection|AMAP]]]]

[[File:Add-on kit.png|thumb|250px|Vehicle add-on armour kit manufactured by [[Composhield]]]]

The earliest known composite armour for armoured vehicles was developed as part of the [[US Army]]'s [[T95]] experimental series from the mid-1950s. The T95 featured "'''siliceous-cored armor'''" which contained a plate of [[fused silica]] [[glass]] between rolled [[steel]] plates. The stopping power of glass exceeds that of steel armour on a thickness basis and in many cases glass is more than twice as effective as steel on a thickness basis. Although the T95 never entered production, a number of its concepts were used on the [[M60 Patton]], and during the development stage (as the XM60) the siliceous-cored armour was at least considered for use, although it was not a feature of the production vehicles.<ref name=xm60/>

The first widespread use of a composite armour appears to have been on the [[Soviet Union|Soviet]] [[T-64]]. It used an armour known as [[Combination K]], which apparently is [[glass-reinforced plastic]] sandwiched between inner and outer steel layers. Through a mechanism called [[thixotropy]], the [[resin]] changes to a fluid under constant pressure, allowing the armour to be [[moulded]] into curved shapes. Later models of the T-64, along with newer designs, used a [[boron carbide]]-filled resin [[aggregate (composite)|aggregate]] for greatly improved protection. The Soviets also invested heavily in [[reactive armour]], which allowed them some ability to control quality, even after production.

The most common type of [[composite material|composite]] armour today is [[Chobham armour]],{{citation needed|date=September 2016}} first developed and used by the British in the experimental [[FV 4211 tank]], which was based on [[Chieftain tank]] components. Chobham uses multiple non-explosive reactive armor plates (NERA), which sandwiches a layer of elastomer (like rubber) between two plates of steel armour. This was shown to dramatically increase the resistance to HEAT projectiles, even in comparison to other composite armour designs. Chobham was such an improvement that it was soon used on the new U.S. [[M1 Abrams]] [[main battle tank]] (MBT) as well. The need to mount multiple angles plates, along with an outer steel layer to protect the armor array, gives the [[Challenger 2|Challenger]] and Abrams their "slab sided" look.

Chobham armor defeats HEAT warheads by disrupting the high speed jet generated by the warhead. The outer steel "burster" plate detonates the shell and protects the composite array from the blast, increasing the armor's multi hit abilities. After making it through the burster plate, the jet penetrates into the first NERA plate, and begins to compress the elastomer. The elastomer quickly reaches maximum compression and rapidly expands, pushing the two steel plates in opposite directions. It is the movement of the steel plates that disrupts the jet, both by feeding more material into the jet's path, and introducing lateral forces to break the jet apart. The effectiveness of the system was amply demonstrated in [[Desert Storm]], where not a single [[British Army]] Challenger tank was lost to enemy tank fire. (However, one was [[Challenger 2 tank#Operational usage|destroyed by friendly fire]] on March 25, 2003, killing two crew members after a [[High-explosive squash head|HESH]] projectile detonated on the commander's hatch causing high-velocity fragments to enter the [[gun turret|turret]].<ref>{{cite web|url=http://www.mod.uk/NR/rdonlyres/C2384518-7EBA-4CFF-B127-E87871E41B51/0/boi_challenger2_25mar03.pdf |archive-url=http://webarchive.nationalarchives.gov.uk/20121026065214/http://www.mod.uk/NR/rdonlyres/C2384518-7EBA-4CFF-B127-E87871E41B51/0/boi_challenger2_25mar03.pdf |url-status=dead |archive-date=2012-10-26 |title=UK Ministry of Defence : Army Board of Inquiry Report |access-date=2016-07-06 }}</ref>) Chobham-type armour is currently in its third generation and is used on modern western tanks such as the [[Challenger 2 tank|British Challenger 2]] and the American [[M1 Abrams]]. The Abrams is also unique in its usage of [[Depleted uranium|depleted uranium armour]] plates in conjunction with composite armour, increasing overall vehicle protection.

All modern third-generation main battle tanks use composite armour arrays in their construction. While many of these vehicles feature the composite armour permanently integrated with the vehicle, the Japanese [[Type 10]] and [[Type 90 Kyū-maru]] MBTs, French [[Leclerc tank|Leclerc]], Iranian [[Karrar (tank)|Karrar]], Turkish [[Altay (tank)|Altay]], Indian [[Arjun (tank)|Arjun]], Italian [[Ariete]]  and Chinese [[Type 96 tank|Type 96]]/98 and [[Type 99 tank|Type 99]] tanks use a modular composite armour, where sections of the composite armour can be easily and quickly switched out or upgraded with armour modules. The adoption of modular composite armour design facilitates far more efficient and easier upgrades and exchanges of the armour.  

Soviet/Russian main battle tanks such as [[T-90]]s [[T-80]]Us and the Chinese Type 96/99s use composite armour in tandem with [[reactive armour#Explosive reactive armour|explosive reactive armour]] (ERA), making it hard for shaped charge munitions such as HEAT projectiles and missile warheads to penetrate the frontal and a portion of their side armour. The most advanced versions of these armours such as the [[Kontakt-5|Relikt and Kontakt-5]] armour provide protection not only against shaped charges but also [[Kinetic energy penetrator|kinetic energy penetrators]] by using the explosive force to shear the projectile apart.

Applique armour has also been used in conjunction with composite armour to provide increased amounts of protection and to supplant existing composite arrays on a vehicle. The German [[Leopard 2|Leopard 2A5]] featured distinctive arrowhead laminated armour modules that was mounted directly onto the turret composite arrays, increasing protection markedly above the previous 2A4 model.  

Composite armour has since been applied to smaller vehicles, right down to [[jeep]]-sized automobiles. Many of these systems are applied as upgrades to existing armour, which makes them difficult to place around the entire vehicle. Nevertheless, they are often surprisingly effective; upgrades with [[MEXAS]] ceramic armour to Canadian [[M113 armored personnel carrier|M113s]] were carried out in the 1990s, after it was realized that it would offer more protection than newly built [[Infantry Fighting Vehicles |IFVs]] like the [[M2 Bradley]].{{citation needed|date=December 2010}}