Baffles are at the heart of a suppressor's durability and performance. They are under extreme stress and must be matched carefully to the intended application. With that in mind, a lot of thought goes into material selection for baffles - and there are several materials that tend to be used fairly frequently.
Each material has its own pros & cons; and, in this article, we're going to spend a little bit of time covering the main ones - as well as their specific advantages and disadvantages.
Aluminum is a very light-weight material that works great in rimfire suppressors. In fact, some of the highest performing & lightest weight .22 suppressors, like the AAC Prodigy, are made from aluminum.
Although it works great for .22 LR, it really isn't strong enough to handle pressures from higher-pressure calibers - like .22 Mag or .17 HMR; so, rimfire suppressors designed for these calibers are typically made from other materials.
Chrome Moly Steel
This steel is a low-cost alternative to some of the better steels and it is used in a few low-cost 5.56mm rifle suppressors.
If you're using a barrel length longer than 14.5" and you don't shoot a lot of volume, then Chrome Moly will work just fine. If, on the other hand, you have a shorter barrel or are a high-volume shooter, I would recommend going with a higher grade of steel.
Stainless steel is probably the most popular material used in suppressor baffles. There are, of course, many grades of stainless steel; but, we're going to lump them all together for the purpose of this article. :)
Stainless steel is durable, corrosion resistant, relatively low cost, handles heat well and holds up well to harsh chemicals. This makes it ideal for use in everything from high-pressure rimfire suppressors all the way up to some of the large bore cans.
In order to make the suppressor even more durable, many models - like the 5.56mm or 7.62mm YHM Stainless Phantoms or the SWR Specwar will use Inconel in the blast baffle and then the rest of the baffle stack is made from stainless steel.
Titanium is light-weight and durable, and is often used where either light-weight or precision are important. It is also, unfortunately, fairly expensive - so most titanium suppressors tend to be the higher-end models.
Although some rimfire suppressors use Titanium, the most common use is in the 7.62mm rifle and large bore rifle categories - where a stainless suppressor can often push close to 2 lbs.
As with stainless steel, several models - like the 5.56mm and 7.62mm YHM Titanium Phantoms use an Inconel blast baffle to improve the suppressor's durability under extreme use (like short barrel rifle usage).
Inconel is an extremely durable alloy that performs very well in suppressor baffles. It can handle extreme abuse & heat, while not being overly heavy. It is, however, hard to work with - so it tends to be used in higher-end suppressors (although some mid-range models will use an Inconel blast baffle).
Only a few suppressor models have a baffle stack made entirely of Inconel - like the AAC M4-2000 or the AAC 762-SDN-6. These suppressors can handle just about anything you could throw at them, from full-auto 5.56mm fire to short barrel rifles.
Every now and then a suppressor manufacturer will claim to have some form of Unobtanium; or, basically a magic material that is the best of all worlds. When I hear claims like this, I tend to be skeptical - but I also look to the manufacturer to see how much I trust those claims.
If, for example, I hear of a new material from Advanced Armament, Silencerco or Surefire - I tend to trust their claims. On the other hand, I tend to doubt some of the second and third tier companies who just don't have the R&D budgets of the larger manufacturers.
We talk to a lot of people with a lot of different needs, and I have found that no single material will fit the bill for every user. That's why there isn't just one - even within the same suppressor category. You really need to determine how you plan to use the suppressor before deciding which materials you should be looking for.
For example, if you want a light-weight, effective .22LR suppressor; then aluminum or stainless steel will work just great for most people. If, on the other hand, you're looking for a long-range/precision suppressor for your .338 LM, then Titanium is probably the way to go.