We draw alloyed aluminum wire of grade 6101 T4. We draw 9.50 mm rod down to 2.50 mm in 9 dies at an average speed of 20 m/sec. The average RA per die is around 25%.

We suffer from frequent wire breaks and doubt that it might be related with the die profile.

1) Which reduction angle and bearing percentage are recommended for such a process to reduce wire breaks?

2) What else might be the root cause of this problem if it is not related with the die profile? Are there any other recommendations to improve our process in general?

Thanks for your kind interest.

Hello Moody,

- Have you done all the basics and are you using all the technical resources you should have at your fingertips?

- Properly designed drawing oil tanks held at the recommended warm temperature?
- A drawing oil specifically recommended for 6101 alloy?
- Lubricity of the oil routinely checked and make up added as necessary?
- A separator for the continuous removal of suspended fines from the oil?
- Drawing machine capstans in sets so that they are ground and polished as a set and not as individuals?
- No grooving on the capstans?
- Drawing dies in sets so each complete set is properly managed and reworked as necessary?
- Drawing dies not replaced as individuals and not left at or lying around the machine for the operators to reuse (good or bad) at will?
- Carbide drawing dies as recommended by the die supplier for 6101 alloy? (Generally a shorter bearing surface.)
- Adequate lubrication to each of the dies.
- Dies aligned properly?
- Die holders of robust design so there is no deflection when running?
- Any unusual noises coming from the machine when running or jogging?
- Do the operators crack the lubricant supply open slightly when jogging to ensure that the dies are properly lubricated?

- Is this a taper drafted machine?
- Are you drafting the machine according to its design and manufacturers recommendation?
- Are you taking a larger reduction at the entrance die?
- Where does the wire normally break? (Say the last 3 dies?)
- How are you welding the rod?

We're sure more of these questions will come to mind as we begin to think about this a bit more.

We haven't bothered to check the drafting you supplied as we are not sure what you mean by the average reduction in area.

Kindest regards,

Peter Stewart-Hay
Principal
Stewart-Hay Associates
www.Stewart-Hay.com

Oh by the way, you asked about staple cement in April 2005 and we answered it the same day for you. www.wirenet.org/forum/viewmessages.cfm?Forum=14&Topic=109 We also asked a return question for our own understanding but you never bothered to answer us. Was there a reason for that action on your part?

Hello peter,
this was the same type of problem we are facing in our industry. So after seeing your reply to this post, i have done my homework before posting...

- Properly designed drawing oil tanks held at the recommended warm temperature?---partially, not for every machine
- A drawing oil specifically recommended for 6101 alloy?---no
- Lubricity of the oil routinely checked and make up added as necessary?---no
- A separator for the continuous removal of suspended fines from the oil?---partially done
- Drawing machine capstans in sets so that they are ground and polished as a set and not as individuals?--No
- No grooving on the capstans?---yes, there are grooves
- Drawing dies in sets so each complete set is properly managed and reworked as necessary?---no
- Drawing dies not replaced as individuals and not left at or lying around the machine for the operators to reuse (good or bad) at will?---no
- Carbide drawing dies as recommended by the die supplier for 6101 alloy? (Generally a shorter bearing surface.)---partially but we are trying to use diamond dies
-Adequate lubrication to each of the dies.---partially
- Dies aligned properly?---yes
- Die holders of robust design so there is no deflection when running?---yes
- Any unusual noises coming from the machine when running or jogging?---yes
- Do the operators crack the lubricant supply open slightly when jogging to ensure that the dies are properly lubricated?---yes

- Is this a taper drafted machine?---no
- Are you drafting the machine according to its design and manufacturers recommendation?---yes
- Are you taking a larger reduction at the entrance die?---no
- Where does the wire normally break? (Say the last 3 dies?)---80- to 85 % breakages are at last 2 dies
- How are you welding the rod?---cold pressure welding

these are the informations i can tell you. What i need the same thing?

what is the main reason for these breakages--a mechanical or a metallurgical....

Hello Bhaup,

Well what can I say? You have already answered your own question. Correct the problems with your machine, get control of your process and then see where you stand.

You do not need to have taper drafting but get to the bottom of the strange noises coming out of the machine. This indeed could be the symptoms of very serious mechanical problems.

Best regards,
Peter J. Stewart-Hay
Principal
Stewart-Hay Associates
www.Stewart-Hay.com

hello peter,
yeah, i can understand that mechanical aspect also. But other then this, there is definitely the metallurgical aspect also about what also i want to know.

Here are some booklets you can buy from the Wire Association International:
- Wire Breaks and Failure Analysis (English)
www.wirenet.org/waistore/productdetail.cfm?productid=152

- Dies: The A to Z of Design and Maintenance
www.wirenet.org/waistore/productdetail.cfm?productid=74

- Diamond Dies: Man-Made vs. Natural
www.wirenet.org/waistore/productdetail.cfm?productid=75

If you are interested in the metallurgy of aluminum alloys for electrical conductors:
- Review your local university engineering library.

- Contact The Aluminum Association www.aluminum.org or,

- Obtain the proper ASTM specification, ASTM B317 / B317M - 07 Standard Specification for Aluminum-Alloy Extruded Bar, Rod, Tube, Pipe, Structural Profiles, and Profiles for Electrical Purposes www.astm.org/Standards/B317.htm
Kindest regards,
Peter Stewart-Hay
Principal
Stewart-Hay Associates
www.Stewart-Hay.com