Originally Posted by
peteeng
Hi Ard- Both are good for structural purposes. 5083 is a rolled plate product. Typically here it would be 5083-H32 which means its quite hard. 6082 is an extruded product and is available here in T5 or T6. The issue for your application is will the part stay flat when you machine it? The 5083 being cold rolled will have internal stress that may spring the part when machined. The 6082 will have less internal stress as its been heat treated after extrusion if in T6. if its 6082-T5 this can be achieved by quenching and stretching at the press so could have some internal stress.
If it where me I'd go with 6061-T6 plate as this is flat and has been solution heat treated and aged after rolling so should have little internal stress. The cost of 5083, 6082 and 6061 is same here. If you are having it machined at a company then ask the machinist which product moves less when machined and use it. If you are going to epoxy the plate to the concrete then machine, these issues are less as the concrete will keep the plate flat. But if you are going to make the concrete block glue the finished machined part to it then the part needs to be true. Then there is the issue of the saddle bottom. If you make a finished machine part you will need true 90deg surfaces to use as a jig to glue the entire thing together,. Or you glue blanks to the block then finish machine. My plan with Milli was to cast the CSA parts - coat with epoxy and bond aluminium parts to these then finish machine... Peter
By the way concrete and aluminium do not like each other so don't "cast-in" aluminium parts unless they are anodised. If concrete and al are touching I'd expect the Al to corrode over time.... that's why I would epoxy it in after casting... steel and concrete are a happy couple... unless in a wet or seaside environment...
edit - I had a quick look and 6082 is available as plate overseas (but can't get it in Oz I think) . So maybe you can get 6082 plate where you are. if so get T6 and that's a good solution....