Re: Ablative Sparking with Titanium Suppressors
That is one rich question you have asked. It can require a long winded answers in order to do it the least bit of justice. It would take a pretty deep and broad answer to cover most of it, so let’s see if an abbreviated response will do.
Probably the wrong use of term "ablative," I believe you may be refering to "artificial environment" or more specifically the use of materials in the blast chamber to contain the effects of the propellant firenball. With that...
If we asked the vast majority of people with a Titanium suppressor to show evidence of just the condition you mention, Ti spark-up, most would be unable to show evidence. If those that are buying Ti cans for precision shooting were asked, the response might even be that the phenomenon does not exist. But, Ti spark-up does exist under the right conditions.
Remembering that Titanium tools are used in some manufacturing application to avoid sparks, it is even harder to understand. In firearms, Ti spark is complicated by the fact that many confuse the effect of unburnt powder exiting the can as being spark-up. But it is very real and certain conditions must be present. Those conditions include, but are not limited to rate-of-fire, caliber, ammunition propellant, barrel length, nature of the titanium used, blast baffle, blast chamber, secondary baffle and more. Given the right set of conditions and you can literally get a shower of sparks. Knowing what causes it is the job of a good designer and they would (should) be very clear as to what applications the can should be used for....and not used for.
http://www.youtube.com/watch?v=h4zDrS9RVIE&feature=youtu.be
http://www.youtube.com/watch?v=11dPIyo3G3A
Whether a fully featured conical or monocore "stack", the effect can be found. Let’s take a closer look. We start with a simple fact, titanium is used in pyrotechnical displays for its bright white effects. Want bright silver in your fireworks? Titanium flake is perfect for you and you probably saw lots of Ti in the last few days. Hardly seems like the kind of material one would use if one's intent is to be incognito, right? Well, if the common condition was that all titanium materials, designs and applications sparked-up, titanium would be off the list. So let’s start off by being as clear as possible, a well designed titanium can, on the right host, in the right caliber, with the right barrel, there is no problem. For the majority, titanium is a remarkable improvement in suppression.
Spark-up comes from the micro shaving of titanium in the first number of baffles. The propellants fire ball hits the blast baffle diverter and micro wear mixes with the remaining burning powder and off it goes. The more of a flat based surface feature, the more the effect can be present. If we remember for a moment that no metal other than titanium welds to titanium, we can see that mixing metals in a fully welded can is a challenge for many shops as other forms of armature manufacturing has to take place. You mentioned using Inconel in the primaries, while it can be a solution for some designs, it is not a universal cure and has construction implications and may negate the primary reason to use Ti in the first place. Which brings us the the real question.
So why use titanium at all? Because, as a general rule, spark-up is not present in low pressure, small bullet calibers, spark up is not found in high pressure, large bullet applications. Spark-up is found in high pressure, small bullet calibers. It is rarely seen in barrels over 18” in almost all calibers. The important point here being the propellant burn rate, barrel length and can design. One uses titanium for its strength, weight and environment characteristics. Got a .308? .338? .408? .50? Got a 9mm, .45, .40, .357, .38? You are pretty much assured that with a quality design you will not experience spark-up. Got a .223 with a 10”, 12”, 14” barrel? Chances are you will see spark-up. Especially if your can was designed for a low firing schedule precision bolt gun and you are running it hot on a SBR and your powder is 1/2 burned and bright when it enters the can. Need your .223 can to be light, made of titanium and work with a 12” barrel? Better get one made by folks that are building exactly for that application and can work with mixed metals. Got a .30 caliber precision rifle and want minimum POI shift? Titanium is your best friend. And then it even gets more confusing as a 249 Saw will most likely not spark in full auto, while another M16/ AR15 with a short barrel and the right propellant will spark like it’s the fourth of July.
Hope that helps get you started in the right direction. Others may have very different insights.
