laser-induced heat treatment on al-alloy

[picaurel]

Hi!

As anyone ever used a CO2 laser to heat-treat an Al-alloy?
I intend to do it on a 6056 Al-alloy, but for the moment I have no precise idea of the beam power (between 100 and 800W) I need, regarding to the relfexion rate of aluminium (if anyone know that I would be very happy!)
I hope you get the idea.

regards.

Aurelien PIC

 

[Goahead]

Hi,
may I ask why would you think that using a laser to heat treat aluminum would be a good idea?
For one thing the efficiency of CO2 laser is quite low.
Then you have to allow time for solution and diffusion processes and finally you should quench rapidly.
I cannot see the benefits.
Good luck.

http://www.welding-advisers.com/

 

[picaurel]

Thx for your post.
Using a laser to heat treat aluminium is part of the research program I am working on. I have to evaluate the feasibility of such a process. I need to heat treat a very local zone (10 mm) so maybe it could be an issue...
I've read that aluminium has a high reflexion rate (about 95%). The laser I can use is a 1.5kW CO2 laser, working with TEM01* mode. I've made some FEA (thermic model) and I am a bit disapointed because we need a lot of power to reach the temperature we need (about 500°C) along the whole thickness (about 6 mm).
People use coatings, acting like "black body"... do you think it could be an idea to improve the efficiency of the process?
If you have any sugestion for another process I would be very gratefull (I also think about a "surface friction process" now)

regards.

 

[NickE]

How about Induction?
nick


Nick
I love materials science!

 

[picaurel]

Hi!

thanks for your suggestion. I don't know so much about induction, but I'm not sure it works very well. Maybe do you know more than me about that?

 

[NickE]

Induction hardening is commonly used for case hardening of steel parts. It involves a (usually) a high voltage, high frequency magnetic field that is then applied to a metal part, through much the same mechanism as a step-down transformer a low voltage high current is generated in the part. This high current causes the part to heat in only the local region subjected to the magnetic field.

There are stoves that use this method so that the cooktop remains (relatively) cool to the touch while the pan (metal only no pyrex) is heated through induction.

I think that the mechanism you use to produce the local heating you need is going to be controlled more by what you are attempting to do to the metal rather than the efficiency of the method you use.

As you state you need to generate 500C in a volume of metal 60mm^2. I am assuming w/o altering the metal around this volume. As Al alloys generally conduct heat really well this is going to be very challenging.

good luck
nick