HS2440 Week 5 Asyn_Copper corrosion in the atmosphere Flashcards
1
Q
Copper corrosion in the atmosphere, common oxides found
A
- cuprite- close to surface
- tenorite- specifically when heated
2
Q
sulphur compounds in copper corrosion
A
- found in atmospheric moisture
- turns into acid
- both common corrosion compounds, forming green products
- antlerite requires lower Ph, is found in more polluted areas (see graph)
- coatings and patina can impact the initiation point, as can sheltered and unsheltered areas
- can be caused by failure of coatings and patinas, causing preferential corrosion
- areas of pooling and condensation can causes localised corrosion.
3
Q
Some sulphur compounds in copper corrosion include B______ and A__________
A
brochantite and antlerite
- flaking of brochanite cases lamination and sites for more local corrosion
4
Q
Some sulphur based copper corrosion products found in the museums environments
A
- black, brown, fuzzy, cauliflower like
5
Q
atmospheric chloride products casing corrosion of copper
A
- products soluble in acidic conditions means increased corrosions in polluted areas
- corrosions products have poor cohesion and adhesion, so they fall off, providing fresh sites for corrosion
6
Q
How organic acids can increase the rate of corrosion
A
- wood as a display product can release organic acids
7
Q
Copper corrodes in contact with organic materials by reacting with…
A
8
Q
image of the dezincification of copper alloys
A
galvanic corrosion similar to decuprication
- plumbing, standing water can cause this
