Aesthetic use of alloys 2

[vicbee]

Hi,
I'm looking to use alloys (aluminium, brass, copper) as part of other elements to make furniture (chairs in particular). I'm not so concerned by the stress properties of these alloys except for corrosion, for aesthetic reasons. In my research I've come across Alloy 535.0 which appears to be the most corrosion resistant. However, considering my use for it, do I need such an alloy? The idea is that the alloy element shouldn't discolor or stain for at least 10 years, no matter where one lives (seaside, dry, humid, cold or hot weather). I am considering stainless steel as an alternative, although I understand it also "stains" with time. I'm really looking for feedback... thanks!

 

[mcguire]

Vicbee
I can't speak well for the aluminum options. I suspect that any of them will corrode in the environments you foresee. Certainly brass will tarnish and copper will form its patina.
I have extensive experience will stainless in many aesthetic environments and I can state unequivicably that with the proper grade selection and sueface finish, stainless will resist all environmental attack in these environments.
I have set up an expert system at the website, stainlesscenter.com, which allows you to choose the grade and surface finish which you need for the specific conditions you need to withstand.
For interior use, low sulfur 304 with a bright annealed finish or a rolled-on textured finish will do the job. For exterior and coastal you will need 316.

 

[vicbee]

Thanks Mcguire. I checked out the website which could be extremely informative if it wasn't so frustrating...Is it in construction? dead links everywhere and every other link wants to send the reader to a "ballianceinc.com" but never gets there...
I haven't made a decision on which alloy to use. Another of my concerns is weight. Which of aluminium and stainless steel are lighter? Can't have extremely heavy chairs...

 

[mcguire]

Sorry about the website...no sponsors to fund completion.
Aluminum is less dense by the same factor that it is weaker so there's very little difference once a design is optimized. If you can use tubular components you will get the most stiffness and strength for a given weight.
You really need to be interactive with a materials person as you design to home in on the best options.