Sailorbaz,
The short metallurgy lesson was excellent.
It is possible to vacuum coat, I think lots of materials, is vacuum coating a viable coating method for aluminium - particularly if the items are to be used in small volumes and they have a physical attribute, in this case strength, that is worth aspiring to. Plasma coating is another process that comes to mind. If this were viable - which materials would be used to provide a protective coating for 7075.
Being specific there are thermal diffusion processes that allow zinc to be deposited as a film on aluminium (and steel - this is the main application). The process would normally be conducted at just over 400 degrees C but can be conducted at lower temperatures (where production rates are also slower). Might this offer a vehicle to provide a protective coating (for 7075). I am in a position to have trials conducted (and have been doing so on steel) but if wisdom suggests this is downright stupid (what is the T6 temperature for 7075) - I'll give it a miss. The process has promise as it can be used to 'galvanise' high tensile steels, 1,200 MPa have been coated, without marked loss of strength. I am to have my own steel samples treated, 950 MPa, in the next few weeks, and have had more conventional samples 690MPa treated without issue. I have only read aluminium can be treated the same way but have seen no results nor samples.
Vyv, thanks for the link to the corrosion cabinet - I'm impressed that you recall what you were doing 30 years ago! I think I was spending a lot of time then queuing for train tickets in deepest China or hoping it was not too cloudy - as civil aircraft navigation in China was based on following roads, railways and rivers (how things change!). Thanks
Jonathan
The short metallurgy lesson was excellent.
It is possible to vacuum coat, I think lots of materials, is vacuum coating a viable coating method for aluminium - particularly if the items are to be used in small volumes and they have a physical attribute, in this case strength, that is worth aspiring to. Plasma coating is another process that comes to mind. If this were viable - which materials would be used to provide a protective coating for 7075.
Being specific there are thermal diffusion processes that allow zinc to be deposited as a film on aluminium (and steel - this is the main application). The process would normally be conducted at just over 400 degrees C but can be conducted at lower temperatures (where production rates are also slower). Might this offer a vehicle to provide a protective coating (for 7075). I am in a position to have trials conducted (and have been doing so on steel) but if wisdom suggests this is downright stupid (what is the T6 temperature for 7075) - I'll give it a miss. The process has promise as it can be used to 'galvanise' high tensile steels, 1,200 MPa have been coated, without marked loss of strength. I am to have my own steel samples treated, 950 MPa, in the next few weeks, and have had more conventional samples 690MPa treated without issue. I have only read aluminium can be treated the same way but have seen no results nor samples.
Vyv, thanks for the link to the corrosion cabinet - I'm impressed that you recall what you were doing 30 years ago! I think I was spending a lot of time then queuing for train tickets in deepest China or hoping it was not too cloudy - as civil aircraft navigation in China was based on following roads, railways and rivers (how things change!). Thanks
Jonathan
