Warning

 

Close
Confirm Action

Are you sure you wish to do this?

Cancel Confirm
AR15.COM
5/27/2011 12:00:17 PM EDT
I have a customer who offered to give me some scrap AR500 steel for my shooting pleasure.  He also said he could "hard coat anodize" a sheet of 1/2" thick aluminum and get the same results.  Any metal experts out there who can confirm or call BS?  I'm taking him up on his offer regardless.
5/27/2011 12:01:51 PM EDT
[#1]
5/27/2011 12:03:29 PM EDT
[#2]
I think you parkerize aluminum and anodize steel or vice-versa.
5/27/2011 12:03:34 PM EDT
[#3]
Anodizing is HARDER than AR500 steel.  It's also 50 microns thick.  
5/27/2011 12:04:31 PM EDT
[#4]
Maybe he'll hard coat the aluminum with AR500..
5/27/2011 12:16:46 PM EDT
[#5]



Quoted:


Anodizing is HARDER than AR500 steel.  It's also 50 microns thick.  


And brittle.



 
5/27/2011 12:17:53 PM EDT
[#6]
If the anodize is a bright color it will be easy to see hits for a little while.
5/27/2011 1:02:22 PM EDT
[#7]



Quoted:


If the anodize is a bright color it will be easy to see hits for a little while.


I'm pretty sure the huge holes through the sheet will provide sufficient contrast.



 
5/27/2011 1:42:07 PM EDT
[#8]
I may be misunderstanding his terminology but as I understand it's a process of using electric current to change the molecular structure.  I know the aluminum has to withstand constant bombardment from steel shot.  The guy builds parts for aerospace so I gave him the benefit of the doubt.  I told him I would bring back the end result after some constant 62 grain bombardment.
5/27/2011 1:44:16 PM EDT
[#9]
Quoted:
I may be misunderstanding his terminology but as I understand it's a process of using electric current to change the molecular structure.  I know the aluminum has to withstand constant bombardment from steel shot.  The guy builds parts for aerospace so I gave him the benefit of the doubt.  I told him I would bring back the end result after some constant 62 grain bombardment.


Had a friend who ran an anodizing company for paintball guns. From what I understand...it does not improve the strength of the steel at all.
5/27/2011 1:48:06 PM EDT
[#10]
Quoted:
I think you parkerize aluminum and anodize steel or vice-versa.




yep

5/27/2011 2:31:13 PM EDT
[#11]





Quoted:



I may be misunderstanding his terminology but as I understand it's a process of using electric current to change the molecular structure.  I know the aluminum has to withstand constant bombardment from steel shot.  The guy builds parts for aerospace so I gave him the benefit of the doubt.  I told him I would bring back the end result after some constant 62 grain bombardment.



Annodizing is just the electrochemical oxidation of the aluminum metal to aluminum oxide.  It's basically aluminum "rust."  The end result is kind of like bluing, which is the chemical oxidation of steel to iron oxide.  





Aluminum oxide is what saphires are made of, and it's extremely hard.  Unfortunately for your aerospace buddy, the aluminum oxide layer is porus and it can't be grown thick enough to make any difference to the bulk mechanical properties of the metal.  It will surface harden it (i.e. resistant to shot peening), make it more abrasion resistant, but not toughen it enough to withstand any major impacts.  You can use a metal punch and a hammer to bust through anodizing; a high velocity bullet will go  through it like butter.




 
 
5/27/2011 2:35:09 PM EDT
[#12]
I smell sulfur in this thread.
5/27/2011 3:02:08 PM EDT
[#13]




Quoted:





Quoted:

I may be misunderstanding his terminology but as I understand it's a process of using electric current to change the molecular structure. I know the aluminum has to withstand constant bombardment from steel shot. The guy builds parts for aerospace so I gave him the benefit of the doubt. I told him I would bring back the end result after some constant 62 grain bombardment.


Annodizing is just the electrochemical oxidation of the aluminum metal to aluminum oxide. It's basically aluminum "rust." The end result is kind of like bluing, which is the chemical oxidation of steel to iron oxide.



Aluminum oxide is what saphires are made of, and it's extremely hard. Unfortunately for your aerospace buddy, the aluminum oxide layer is porus and it can't be grown thick enough to make any difference to the bulk mechanical properties of the metal. It will surface harden it (i.e. resistant to shot peening), make it more abrasion resistant, but not toughen it enough to withstand any major impacts. You can use a metal punch and a hammer to bust through anodizing; a high velocity bullet will go through it like butter.

As a toolmaker, I can vouch for this.



It makes the surface very hard and resistant to wear (hence the use in firearms made of AL) but a .223 will sail right through that plate.



5/27/2011 5:47:04 PM EDT
[#14]
Going out on a limb here guessing what he might have been referring too. First, hard-anodizing aluminum will not make it noticeably more resistant to bullets and uses electrical currents to anodize the base metal. Face-hardened armor steel was made by the Germans in WW2 using electricity to heat the surface by electrical induction among other methods. Different base material (aluminum versus cold-rolled steel), different electrical setup (anodizing bath versus induction heating), but maybe he crossed neurons on the common electricity?
5/27/2011 5:56:59 PM EDT
[#15]
Quoted:

Quoted:
Anodizing is HARDER than AR500 steel.  It's also 50 microns thick.  

And brittle.
 


And much lower density.
5/27/2011 7:02:23 PM EDT
[#16]
Quoted:

Quoted:
I may be misunderstanding his terminology but as I understand it's a process of using electric current to change the molecular structure.  I know the aluminum has to withstand constant bombardment from steel shot.  The guy builds parts for aerospace so I gave him the benefit of the doubt.  I told him I would bring back the end result after some constant 62 grain bombardment.

Annodizing is just the electrochemical oxidation of the aluminum metal to aluminum oxide.  It's basically aluminum "rust."  The end result is kind of like bluing, which is the chemical oxidation of steel to iron oxide.  

Aluminum oxide is what saphires are made of, and it's extremely hard.  Unfortunately for your aerospace buddy, the aluminum oxide layer is porus and it can't be grown thick enough to make any difference to the bulk mechanical properties of the metal.  It will surface harden it (i.e. resistant to shot peening), make it more abrasion resistant, but not toughen it enough to withstand any major impacts.  You can use a metal punch and a hammer to bust through anodizing; a high velocity bullet will go  through it like butter.
   


That's about what I thought, without the specifics of course.  He did offer some AR500 steel scraps I could use once I figure out how to mount them.  I didn't want to push it and ask him to waterjet some holes for me.  Thanks for the info.