passivation
Let an agent explain passivation, relay mechanisms, methods and applications from materials and corrosion sources, describe sherardising as a related process, and distinguish passivation from galvanising, anodising, painting and pickling, without giving hazardous chemical handling instructions beyond general safety.
Research draft, second pass
A second pass drafted this model: the structure a model of this thing needs, and what is known about it in the world. The line under this one says how the second half was obtained - researched against sources, or recalled without web access, in which case nothing here was read anywhere and every claim is a lead to verify. Unreviewed either way.
written by Claude from model knowledge without web access - no source was read, every claim is a lead to verify
Researched by: Claude
Purpose and description
Let an agent explain passivation, relay mechanisms, methods and applications from materials and corrosion sources, describe sherardising as a related process, and distinguish passivation from galvanising, anodising, painting and pickling, without giving hazardous chemical handling instructions beyond general safety.
The treatment of a material surface to make it less reactive, typically by forming a thin protective oxide or other film, as when stainless steel is passivated with nitric or citric acid, aluminium forms a natural oxide layer, and semiconductors are passivated to reduce surface defects; the registry alias sherardising names a diffusion zinc coating process, which is a related corrosion protection treatment rather than passivation in the strict sense.
What it is for: Reducing surface reactivity and corrosion.
It can be explain mechanisms; relay methods and applications; describe related processes; distinguish related treatments.
Distinguishing features
Thin film
Reduced reactivity
Chemical or natural
Metals and semiconductors
What it looks like
Usually invisible; a thin film on metal or semiconductor surfaces.
Physical character
passive film thickness: a few nanometres note - stainless steel
standards: ASTM A967 and A380 note - stainless steel
sherardising temperature: about 320-500 C - zinc diffusion
How it is recognised
Formation of a protective passive surface film
Stainless steel passivation, aluminium oxide film, semiconductor passivation; sherardising as related
Galvanising adds zinc; anodising thickens oxide electrically; painting adds coatings; pickling removes scale
Related models
is a kind of - in registry terms
protects -
is contrasted with -
is related to -
In practice
Families and kinds
nitric and citric acid passivation of stainless steel
natural oxide passivation of aluminium and titanium
semiconductor surface passivation
chromate and alternative conversion coatings
diffusion coatings such as sherardising as related treatments
Standards and regulation
ASTM A967 and A380
Restrictions on hexavalent chromium under REACH
Occupational chemical safety rules
Failure modes and hazards
Acid handling hazards
Incomplete passivation causing corrosion
Confusing passivation with other coatings
Also called
Where this came from
wikidata · CC0 1.0
Drafted structure
Bundle to layer to finding to question, as the second pass will find it: 4 bundles · 8 layers · 8 findings · 16 questions.
Understand What passivation is.
Science.
Definition
Definition.
Definition
Definition.
- What is passivation, and how does it differ from galvanising, anodising, painting and pickling? definition
- Is the question about metals, semiconductors, standards or hazardous chemical handling best left to trained staff? boundary
Kinds
Kinds.
Kinds
Kinds.
- What are stainless steel, aluminium and semiconductor passivation, and what is sherardising? definition
- Which entry fits the specific kind? action
Science Mechanism.
Science.
Films
Passive films.
Films
Films.
- How do passive oxide films form and protect metals? provenance
- Which references are standard? provenance
Breakdown
Breakdown.
Breakdown
Breakdown.
- How do chlorides and damage break down passive films, causing pitting? provenance
- Which sources are cited? provenance
Industry Industrial practice.
Regulation.
Standards
Standards.
Standards
Standards.
- What do ASTM standards specify for passivation and testing? provenance
- Which entry fits ASTM International? action
Semiconductors
Semiconductors.
Semiconductors
Semiconductors.
- How is surface passivation used in solar cells and transistors? provenance
- Which entry fits solar cell? action
Context Related processes.
Context.
Sherardising
Sherardising.
Sherardising
Sherardising.
- What is sherardising, and how does it compare with hot-dip galvanising? provenance
- Which entry fits galvanization? action
History
History.
History
History.
- How did Faraday and others discover passivity? provenance
- Which entry fits the history of corrosion science? action
What the second pass must settle
- Should sherardising be a separate primary entry?
- How should corrosion engineering sources be linked?
- The registry alias sherardising is a related coating process and should be recorded as such