NZ337704A - Process for forming ceramic coating on valve metal - Google Patents
Process for forming ceramic coating on valve metalInfo
- Publication number
- NZ337704A NZ337704A NZ337704A NZ33770497A NZ337704A NZ 337704 A NZ337704 A NZ 337704A NZ 337704 A NZ337704 A NZ 337704A NZ 33770497 A NZ33770497 A NZ 33770497A NZ 337704 A NZ337704 A NZ 337704A
- Authority
- NZ
- New Zealand
- Prior art keywords
- metal
- ceramic coating
- electric current
- maximum height
- opposite electrode
- Prior art date
Links
Landscapes
- Other Surface Treatments For Metallic Materials (AREA)
Abstract
he invention provides a process for forming a ceramic coating on a valve metal selected from the group consisting of aluminium, zirconium, titanium, hafnium and alloys of these metals. The process includes immersing the metal as an electrode in an electrolytic bath comprising an aqueous solution of an alkali metal hydroxide, providing an opposite electrode immersed in or containing the electrolyte liquid, passing a modified shaped-wave alternate electric current from a high voltage source of at least 700 V through a surface of the metal to be coated and the opposite electrode, wherein the modified shaped-wave electric current rises from zero to its maximum height and falls to below 40 % of its maximum height within less than a quarter of a full alternating cycle, thereby causing dielectric breakdown, heating, melting, and thermal compacting of a hydroxide film formed on the surface of the metal to form and weld a ceramic coating to the metal, and changing the composition of the electrolyte while the ceramic coating is being formed, the change being effected by adding an oxyacid salt of an alkali metal. The invention also provides apparatus for carrying out this method.
Priority Applications (1)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
NZ337704A NZ337704A (en) | 1997-03-11 | 1997-03-11 | Process for forming ceramic coating on valve metal |
Applications Claiming Priority (2)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
NZ337704A NZ337704A (en) | 1997-03-11 | 1997-03-11 | Process for forming ceramic coating on valve metal |
PCT/GB1997/000664 WO1998040541A1 (en) | 1997-03-11 | 1997-03-11 | Process and apparatus for coating metals |
Publications (1)
Publication Number | Publication Date |
---|---|
NZ337704A true NZ337704A (en) | 2000-01-28 |
Family
ID=19927497
Family Applications (1)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
NZ337704A NZ337704A (en) | 1997-03-11 | 1997-03-11 | Process for forming ceramic coating on valve metal |
Country Status (1)
Country | Link |
---|---|
NZ (1) | NZ337704A (en) |
-
1997
- 1997-03-11 NZ NZ337704A patent/NZ337704A/en unknown
Similar Documents
Publication | Publication Date | Title |
---|---|---|
US5616229A (en) | Process for coating metals | |
CN100482867C (en) | Oxidising electrolytic method for obtaining ceramic coating at surface of metal | |
KR19980702996A (en) | Anodizing Method for Magnesium and Alloys Containing Magnesium | |
FI103674B (en) | A method of electrochemically depositing a surface of a machine part | |
KR920011628A (en) | Metallic articles having supports in the form of improved plasma sprayed surfaces, methods of making flat metal surfaces and electrolyzers | |
US10941502B2 (en) | Electrolytic process and apparatus for the surface treatment of non-ferrous metals | |
US20030094377A1 (en) | Process for forming coatings on metallic bodies and an apparatus for carrying out the process | |
ATE193735T1 (en) | METHOD AND SUBJECT FOR COATING METALS | |
NZ337704A (en) | Process for forming ceramic coating on valve metal | |
WO1998040541A1 (en) | Process and apparatus for coating metals | |
CA1066650A (en) | Electroplating aluminium stock | |
HUP0001068A2 (en) | Process and apparatus for coating metals | |
Leisner et al. | Electroplating of porous PM compacts | |
RU2194804C2 (en) | Method for forming protective coatings onto surface of metals and alloys | |
KR970707325A (en) | PROCESS FOR PRODUCING A CORROSION AND WEAR-RESISTANT OXIDE LAYER WITH LOCALLY REDUCED LAYER THICKNESS ON THE METAL SURFACE OF A WORKPIECE | |
WO1995018250A1 (en) | Method of producing a coating on metals with unipolar conductivity | |
RU2775013C1 (en) | Method for plasma-electrochemical formation of nanostructured chromium coating and device for implementing the method | |
KR100524691B1 (en) | the method to create substate-protective covers by Anode-cathodic microarc oxidation | |
RU2771409C1 (en) | Method for plasma-electrochemical formation of nanostructured chromium coating and device for implementing the method | |
GB659927A (en) | Improvements relating to the coating electrolytically of metal articles | |
SU926083A1 (en) | Method for electrolytically applying silicate coatings | |
RU2190044C2 (en) | Apparatus for microarc applying of oxide coating on metals and their alloys | |
KR100260764B1 (en) | Process for microarc oxidation of large size articles made of aluminum alloys | |
RU2046157C1 (en) | Method for microarc oxidation of valve metals | |
BR9714578A (en) | Process and apparatus for coating metals |