What Happens When a Bullet Hits Ceramic Armor?

Ceramic armor stops high-velocity rifle threats by breaking them apart on its hardened surface. Below we will dive into more depth into what happens to ceramic when it is hit by a bullet.

What is Ceramic Armor? 

Ceramic has long disputed origins going back thousands of years. It can be found in a wide range of uses from flooring, to pottery, inside water heaters, and other common household items like dinner plates. Ceramic has several unique properties that can make its usage as armor beneficial. 

Ceramic has a surface hardness close to a diamond. This lends itself well to stopping high-velocity hardened-steel reinforced projectiles that would otherwise penetrate other armor types. Bear this in mind; not all ceramics can be used as armor. In this article, when we mention “ceramic” as an armor type, we are referring to any 1 of the 3 ceramic types used in armor: Aluminum Oxide, Boron Carbide, and Silicon Carbide.    

The Pros of Ceramic Armor

Why is ceramic’s surface hardness so important? By having such a hard surface, most modern projectiles (except a few) including hardened steel inserts are resisted or stopped by it entirely. Ceramic is capable of addressing at least one single shot of a threat type that may otherwise penetrate another armor material like steel or polymer. It is capable of addressing many large-caliber hunting rounds and armor-piercing threats that may be encountered on the battlefield. To date, ceramic is the only material that can meet the NIJ's rigorous 0101.06 and upcoming 0101.07 standards for level IV / RF3 requirements. The requirements to meet this standard are simple, yet fierce: stop a single 30-06 M2 AP type round (one of the most difficult to stop) and mass-produced cartridges to see widespread usage in the modern era.  

What Happens When Ceramic is Shot? 

When the projectile strikes the armor, the round partially penetrates into the surface of the ceramic and begins to create a “bowl” shaped crater. Around roughly the same time as this crater is formed, the projectile will have typically imploded on itself, redirecting its newly formed fragmentation in a dispersal pattern within the strike face crater. Simultaneously, the surface of the strike face is now structurally compromised.

There are four important things to know when discussing ceramic stopping a round:

1. The projectile fired is interfacing with a surface that is much harder than it: This ensures even hardened-steel type armor-piercing projectiles like the 30-06 M2 round (7.62x63mm) mentioned above is broken apart on the strike face. 
2. Redirects fragmentation of the projectile into itself: After the strike face has been pockmarked or cratered by the projectile, the unique cratering profile of the armor redirects fragmentation of the projectile into itself, preventing some fragmentation from leaving the surface of the armor. This is best described as pouring water into a bowl from about a foot above the empty bowl. Some liquid is likely to make its way up to the surface of the bowl and slosh out, but most will be contained within. A similar effect happens with ceramic armor and fragmentation redirection. Although there is some frag, it is not as much as other armor types. 
3. After a single shot, the ceramic strike face will be structurally compromised: Given the range of manufacturing processes, ceramic armor typically breaks down into multi-hit or single-hit categories. Regardless, ceramic is destroyed when it is shot. The difference is if the destruction of the strike face can be mitigated to as small of an area as possible. Some multi-hit plates use a tile ceramic matrix to control strike face destruction. Others use dual adhesives to keep a monolithic strike face in place even as it breaks apart. The highest point of compromise will always be at the epicenter of the previous shot. For example, any subsequent shot on top of the previous will likely pass through the armor, regardless of multi-hit capabilities. Any subsequent shot that spaces further out from the previous hit has a higher likelihood of being stopped by the armor. Basically, the multi-hit likelihood will be based on how badly the ceramic has fractured from the previous hit(s).
4. All level IV ceramic plates require some form of soft armor behind them to ensure both the projectile and any subsequent ceramic spalling are captured: This especially applies to rifle rounds that have enough mass and velocity to destroy the strike face (all the way through). The soft armor is called a “Backer”. All standalone level IV ceramic plates, like our C2 Multi-Hit plate, have a backer built in so additional soft armor is NOT needed to be placed behind the plate. All DOD-issued ESAPI or XSAPI plates require additional soft armor layers to be used in conjunction with the inserts to be rendered safe for use. Using ceramic plates without a backer can be lethal to the wearer. 

The Cons of Ceramic Armor

You may be asking yourself: With the ability to stop armor-piercing rounds, what else really matters when it comes to armor? That depends on the end user's needs. It's possible you have seen someone online making the absolute claim “only buy ceramic”, however, the upkeep of ceramic plates is not as straightforward as this claim may seem. Below we will talk about some of the realistic cons of using ceramic. You may still need ceramic plates, but hopefully, after this, you will have a better idea if they are the right choice based on your needs:

• Multi-Hit Capability: Since ceramic is designed to break apart when hit, its ability to take more than one round (or how it takes multiple rounds) is always questionable. With some multi-hit ceramic plates, you may get another two or three shots stopped provided they are spaced far enough apart. However, regardless if the plate is multi-hit or not, another shot to the same spot as the last and you will see penetration into the wearer. The armored backer will not stop a rifle’s second hit in the same spot once the ceramic in front of it has been destroyed. When a soldier in the military is shot in their vest, they are issued a new plate immediately (once cleared to return to duty). This is a logistical capability the U.S. military has, however, you may not, especially in a “civil war” type environment where purchases are monitored and restricted.
• Fragility: Since ceramic is so hard, it is also brittle from blunt impact. All good ceramic plates will have a fiber wrap with encased foam to prevent rough handling damage, but not all. Our C2 Multi-Hit plate uses FragLock coating as a polyurea shell to encase the ceramic. When choosing ceramic armor, keep in mind it is the only armor type you can destroy without actually shooting it. Also, make sure to take note when donning and doffing your carrier and how you store your plates to avoid rough handling. Don’t simply heave your carrier on the floor from chest level. 
• Sub 2” Edge Protection: All ceramic plates require a deduction of 2” from the edge of the plate in terms of the actual protective surface. Any shot here (known as an “edge shot”) has the ability to penetrate the plate due to a lack of surface area. All NIJ testing is done 2” from the edges of the plate and any shots that hit and penetrate here are tossed out. This means a 10” x 12” size ceramic plate will actually only provide 8” x 10” of protection. Other armor materials like UHMWPE, steel, and kevlar have between sub 1” or full edge to edge surface protection. 
• Shelf Life: All ceramic plates have a 5-year shelf life. This has to do with the secondary armor and the backer's shelf life. Backers are made of aramid (soft armor) or UHMWPE (polymer armor) and only have a 5-year shelf life. This means you will need to replace ceramic armor faster than other types of armor, up to four times in the single life span of steel. 
• Required Backer: All stand-alone level IV plates have a built-in soft armor backer. This backer is required to ensure any round that is not fully broken apart and stopped by the ceramic strike face is effectively stopped on the last few layers of the armor. This also prevents a unique ceramic property (most commonly and erroneously associated with steel armor) called spalling. Armor issued by the military, for example, has soft armor issues separately. Once the soft armor expires it is replaced and paired with the older strike face, provided it is still serviceable. 
• Weight: Another common misconception is that ceramic is lightweight or at least lighter than steel. Most ceramic plates on the market weigh between 5 to 8 pounds. Consider various steel plates that can weigh between 5.5 to 9 pounds. This means no matter which way it's argued, steel and ceramic can be even, with the favor of this metric swaying depending on manufacture and plate type compared. 
• Cost: It's again often misinformed that ceramic “only costs a little more than steel”. While this may be true upon initial comparison, when you consider the 5-year shelf life of ceramic compared to the 20-year shelf life of steel, that talking point only is true in the first 5 years. A more accurate comparison of the cost would be to multiply the cost of a ceramic plate x4 because over a 20-year period, that is the actual cost you will spend to maintain ceramic plates over that time frame. 
• Fragmentation and Spall: the last con is more of a misconception. It is that ceramic armor does not “spall”. First, let's define two commonly used (but erroneously interchanged) terms:
1. Fragmentation which comes from the projectile
2. Spall which comes from the armor plate

In terms of steel armor; the projectile is smashed completely on the surface of the armor, and redirects bullet fragmentation outward in all directions, while the steel plate remains intact. 

Spalling only occurs when parts of the armor are knocked off the original piece and become high-velocity projectiles themself. Steel, while susceptible to bullet fragmentation, does not spall. Ceramic (while capable of mitigating some fragmentation due to its self-destructing property), spalls heavily when shot due to its brittle nature. This is again why soft armor backers are required with all ceramic armor usage. 

Conclusion

Is ceramic body armor for you? That depends. 

• Are you able to adhere to the needs of care for ceramic armor long term? 
• Are you financially and logistically equipped if the ceramic plates you have or intend to purchase are shot in the next 5 years?
• Are you financially and logistically equipped to replace them during a time of war, possibly even civil? 

If you are able to maintain the care of these plates long-term then, by all means, do so. Most do not have a supply chain like the military that can provide them with a replacement plate as soon as possible. If you have concerns with the durability, multi-hit rating, and long-term cost of upkeep - perhaps another armor type may be more in line with your individual needs. 

In closing, when assessing this conversation with modern material solutions and the wide range of manufacturers on the market, the “Steel vs Ceramic” conversation becomes dynamic. Read more details in our Steel vs Ceramic Body Armor article.

The conversation is often erroneously approached as one or the other. The reality is more in line with which armor type has the best application for your individual needs. No two people are the same and neither are their armor needs. This is no different than when you choose an AR-15 or an AK-47 as your go-to rifle or choose 9mm vs 45 as your carry caliber. The one you have on you when you need it is always the best one.