We are working on a vacuum table with heating capability. Table is 10'X5' with the vacuum bag on top of it. The current bottom plate is some kind of pressed wood (MDF-like), which when heated deforms considerably.
We intend to replace this with an aluminium bottom plate. Max service temperature is 150C (300F), with typical usage being steel blocks up to half a tonne placed on top, vacuum applied and the heaters heating the steel plates/blocks to a typical average temp of 100C (232F). Peak temps get close to 150C, but never surpass this.
The new bottom will be just over an inch thick to keep both elastic deformations low enough and stresses low enough (10 MPa peak, about 1500 PSI). It is free to expand laterally to avoid thermal stresses.
I know enough about aluminium to worry about thermal fatigue and loosing temper (pun intended), but not enough to identity whether these are real concerns.
To the best of my knowledge, for example with T6, the max temperature we expect in service is close enough to the artificial ageing temperature to risk "over-aging". Further it is hard to find quantitative data regarding thermal fatigue at these stress levels (<10 MPa, 1500 PSI).
I presume this is a fairly common problem for machined composite molds for autoclaves for example.
So, which commercially available, affordable alloys would be suitable for this application?
We intend to replace this with an aluminium bottom plate. Max service temperature is 150C (300F), with typical usage being steel blocks up to half a tonne placed on top, vacuum applied and the heaters heating the steel plates/blocks to a typical average temp of 100C (232F). Peak temps get close to 150C, but never surpass this.
The new bottom will be just over an inch thick to keep both elastic deformations low enough and stresses low enough (10 MPa peak, about 1500 PSI). It is free to expand laterally to avoid thermal stresses.
I know enough about aluminium to worry about thermal fatigue and loosing temper (pun intended), but not enough to identity whether these are real concerns.
To the best of my knowledge, for example with T6, the max temperature we expect in service is close enough to the artificial ageing temperature to risk "over-aging". Further it is hard to find quantitative data regarding thermal fatigue at these stress levels (<10 MPa, 1500 PSI).
I presume this is a fairly common problem for machined composite molds for autoclaves for example.
So, which commercially available, affordable alloys would be suitable for this application?
