Ballistic Aluminum plate

By ravi theCobra (**)

Date 09-04-2008 15:36

What welding procedures do you need ?

Do they have a requirement to meet impacts or COD ' s ?

By cfrancis (**)

Date 09-04-2008 16:34

I havent been given any particular requirements as of yet. I just have not had any experience with this particular material as of yet, and certainly would like to get all the information/expertise on it that I can from those of you who have this type of experience. So really, any procedural information you can lend would be much appreciated.

Thanks

By 803056

Date 09-05-2008 00:10

Use GMAW in the spray transfer mode and clean, clean, clean the aluminum before welding.

Best regards - Al

By cfrancis (**)

Date 09-05-2008 12:50

Thank you. Any particular fillers....? Look like either a ER5356 or ER5183 matches this grade ? With a thickness of .500", would anyone recommend a He/Ar mix ? Or just 100% Ar ? Any other special circumstances or procedural recomendations by any one ?

Thanks !

By 803056

Date 09-05-2008 13:21 Edited 09-22-2008 01:53

Find out what specific military welding standards apply to this project. You will be required to qualify the welding procedures if you are working to a military fabrication standard. The drawings or the standard should direct you toward the filler metal to be used. You may want to obtain some outside help if you have never worked with the military before. They have a particular way of doing things that causes a lot of companies to experience heart papulations until they get a feel for how things are done.

I would recommend using straight argon for 1/2 inch or under if you are using GMAW spray transfer. Don't try to use pulsing or short circuiting transfer.

Contact me directly if you have specific needs or questions on this.

Best regards - Al

By cfrancis (**)

Date 09-05-2008 17:22

Thank you very much Al. I will certainly contact you directly when I get that far. I certainly appreciate that offer of help...

By 1fastguy (**)

Date 09-22-2008 17:59

Why would you not use Pulse Mode? We do pulseing on 6061 T6 and 5083 base metals 3/8-1/2-3/4 thichness all the time with 100% Argon, ER5356 filler rod and it works fantastic!

By Lawrence (*****)

Date 09-22-2008 19:30

The question of why, rather than why not is important here.

Why use a process (GMAWP) that is specifically designed to minimize heat input, on a project where maximum heat input is desirable? Thick aluminum wants to be welded hot and fast. GMAWP will simply reduce travel speed and add to the risk of sidewall fusion issues.

GMAWP is a great idea for thinner aluminum, when burn-thru or distortion is an ongoing issue. The minimized heat input in the spray transfer produced by GMAWP can be a noticable benefit vs the heat control issues inherant with spray transfer and the lack of fusion issues associated with short circuiting of aluminum.

So why pay for all the whistles and bells of a GMAWP power supply if you can do the job with standard CV stuff?

Sure GMAWP works fantastic on thick stuff... But so does traditional CV mig at greater productivity rates and less cost.

By 1fastguy (**)

Date 09-23-2008 13:41

Larry, for the control issue alone it is well worth running GMAW-P vs GMAW with thick Alm. In pusle mode you get less smut, less spatter, less destruction of consumables,(downtime),way more consistent and controlable welding,(uptime). Another area that most people forget is interpass tempature on thick ALM. With GMAW you constiently have to monitor the heat input and not run over about 250-275 degress(downtime). With GMAW-P this is almost never an issue.
When we runn pulse vs non pulse we get more weld time in the pulse mode by far! The trade off is pulse might be a little bit slower but you can run for days and days before any down time vs GMAW where the operator has to change contact tips, clean nozzles, check temp. etc...Just my 2 cents

By Lawrence (*****)

Date 09-23-2008 16:12

Fastguy,

That's pretty convincing testimony!

I still wonder that if in some cases the WPS on the pulse program is simply tighter than with the parameters on the Spray Mig.

Tighter process control always makes for better quality.

I'm slightly skeptical about some of the GMAWP claims that the vendors put out there. But folks like you who actually do the work are the ones who really should be listened to.

By 1fastguy (**)

Date 09-23-2008 17:07

Larry, You are correct on the tighter WPS parameters. What is nice about GMAW-P is that you can repeat and almost 100% guarantee the parameters will be meet in the WPS every time because of the programs in the welding machines, so that means you can tighten down the welding parameters on the WPS and I am always skeptical of any claim a salesman or vender makes when it comes to welding equiptment! That is why I test, test, test and then test some more! Take care

By david.crawford (*)

Date 09-14-2008 05:40

What size filler are you using? if you are using 1/16" you might want a 50/50 mix of Argon/Helium, or 75/25 Argon/Helium. If you are just using .047" or less, you can probably use 100% Argon.

By Kix

Date 09-15-2008 19:15

We use 1/16' filler with 100% argon on 1/2" 6061-t6 material and it does the job, but I feel some sort of helium mix would make things a little bit easier and cosistent. We can get one of those Miller 350P's with a python gun to pulse a nice weld in on 1/2" material with .047 and 100% argon. Duty cycle has not been an issue as of yet. lol It does such a nice job that I'm going to qualify some procedures for it when I get a minute. Pulsing the 1/16" wire is a no go.

By Goose-em (**)

Date 09-20-2008 02:49

If you are dealing with the Military they will have specifics on filler metal, gas, etc. There will also be a qualification process listed in the project peculiar document and references to the applicable MIL-STD, most likely MIL-STD-248C 1973.

I deal with the military everyday in my business and there are many hoops to jump through. It is not simply a matter of, hey we weld stuff and bid on the project so now we are going to do it.

They will expect PQR and WPS for everything. Aslo tensiles, bends charpys etc.

If you are the welder all of your questions will be answered by work instructions and WPS. If you are the business owner you will need to produce these documents prior to being awarded the contract.

Just my .02 cents worth.

By 803056

Date 09-22-2008 02:34

I agree with Kix; pulsing on half inch thick aluminum is not necessary.

I would advocate using 100% argon for aluminum less than one inch in thickness. The addition of helium will increase the cost substantially.

Aluminum has a high coefficient of thermal conductivity, therefore you need as much heat as you can produce to minimize fusion type defects. You should be able to weld in all positions using spray mode transfer without difficulty.

MIL-STD-248 has been replaced by NAVSEA S9074-AQ-GIB-010/248 and MIL-STD-278 has been replaced by NAVSEA S9074-AR-GIB-010/278. As suggested by the titles, both are NAVSEA documents used for welding naval vessels and equipment.

Another military standard that may be appropriate is MIL-STD-1946A Welding of Aluminum Armor. The welding procedures have to be qualified and a sample subjected to ballistic testing. I didn't see any recommendations for the base metal/filler metal combinations. You purchase order will specify the appropriate welding standard. The contract document may also specify the recommended or the required filler metal if there is still a question on that issue.

Good luck - Al