AA CA92-2002 Care of Aluminum (Sixth Edition)《铝的维护.第六版》.pdf

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1、 table of contents 1 aluminum finishes 1. non-finished 1. anodized 2. chemical conversion 2. painted 2. porcelain enameled 2. plated 2. laminated 2 simple finish tests 3. simple finish tests 3 cleaning aluminum 5. common sense cleaning rules 6. cleaners and techniques 6. mild soaps and detergents an

2、d non-etching cleaners 6. solvent and emulsion cleaners 6. abrasive cleaners 7. etching cleaners 8. special cleaners 4 care and cleaning of aluminum products 9. 9. 9. 9. 9. 1 o. 11. 11. 13. 13. 13. 14. 15. 17. architectural aluminum pre-installation practices on-site storage installation care protec

3、tive coverings when to insulate care after installation general cleaning tips protection after cleaning transportation equipment automobiles trucks, trailers and railhapid transit in and around the home mobile homes and recreational vehicles 5 pre-fabrication handling and storage 18. proper handling

4、 18. mechanical damage 19. water-staining 19. storage 20. air-borne contamination 20. oiling and interleaving reference tables 20. easy-reference to cleaners 21. list of protective coatings 22. list of cleaning products SIXTH EDITION, AUGUST 2002 The 2002, sixth edition has beeen revised through the

5、 support of the Technology Committee of the Sheet and Plate Division. ALUMINUM ASSOCIATION SHEET AND PLATE DIVISION COMPANIES Alcan Inc. Kaiser Aluminum and Alcoa Inc. Chemical Corporation AMAG Rolling GmbH Logan Aluminum, Inc. ARCO Aluminum, Inc. Nichols Aluminum Coastal Aluminum Rolling Ormet Corp

6、oration Corus Aluminium Rolled Precision Coil, Inc. Milis, Inc. Pechiney Rolled Products Products, USA Spectrulite Consortium, Inc. Co. Corporation Jupiter Aluminum Wise Metals Group Corporation Gulf Aluminium Rolling Mill United Aluminum About The Aluminum Association The Aluminum Association, base

7、d in Washington, DC with offices in Detroit, MI, represents US. and foreign- based primary producers of aluminum, as well as recyclers, and producers of semi-fabricated products. Member companies operate almost 200 plants in the United States and many conduct business worldwide. NOTICE Disclaimer Th

8、e use of any information contained herein by any mem- ber or non-member of The Aluminum Association is entire- ly voluntaty The Aluminum Association has used its best efforts in compiling the information contained in this book. While the Association believes that its compilation proce- dures are rel

9、iable, it does not warrant, either expressly or implied, the accuracy or completeness of this information. The Aluminum Association assumes no responsibility or lia- bility for the use of the information herein. All Aluminum Association published standards, data, speci- fications and other technical

10、 materials are reviewed and revised, reaffirmed or withdrawn. Users are advised to con- tact The Aluminum Association to ascertain whether the information in this publication has been superseded in the interim between publication and proposed use. The Aluminum Association Incrporaied 900 19th Street

11、, N.W., Washington, D.C. 20006 www.aluminum.org I non-finished anodized finishes care of aluminum introduction J- painted finishes a chemical conversion finishes aluminum fin is hes One of aluminums most desir- able attributes is its natural resist- ance to corrosion. When the bare metal is exposed

12、to air, it readily combines with oxygen to form a tough, transparent, protective oxide coating. This oxide layer allows alu- minum products to perform virtually “maintenance-free” in a wide variety of environments. Aluminum can also be treated or “finished” in many ways. Painting, anodizing and plat

13、ing with other met- als can provide a variety of surface appearances and provide further protection to the base metal. Apart from the purely aesthetic reasons for keeping aluminum sur- faces clean, there are also practical reasons as well. In certain aggres- sive environments, especially those conta

14、ining salt, excessive surface oxidation and pitting can occur. These can shorten service life of the aluminum by reducing its strength and promoting fatigue failures. All the finishes, including the non-finished or bare, may be kept clean and bright with mild soap and water alone. However, if cleani

15、ng has been postponed for too long, and the dirt is especially tenacious, a more aggressive cleaner and clean- ing technique may be required. This publication will provide insight into the proper methods and materials to be used to maintain the various finishes of aluminum prod- ucts - from architec

16、tural to trans- portation, from industrial to home and recreational products. Sections include: tips to help identify surface finish- es properties of various types of cleaners step-by-step care and cleaning procedures for a variety of aluminum products proper handling and storage techniques for alu

17、minum products a comprehensive list of commer- cially available cleaning products and their producers Aluminum is available commer- cially in at least seven different fin- ishes, each with its own characteris- tics. Aluminum care and cleaning programs must, therefore, be tai- lored to the metals fin

18、ish as well as to the needs and conditions of serv- ice. non -f i n is hed Non-finished (bare) surface is simply the metals own, self-produced oxide layer. It is thin but tough, transpar- ent, tenacious and protective. Bare finishes vary in appearance depend- ing on fabrication technique. The textur

19、e may be smooth and mirror- like, similar to satin or embossed with stucco, woodgrained or other patterns. With time, the unfinished surface may darken and discolor. Near the sea it tends to turn gray. In cities and near factories it tends to turn brown or black. anodized finishes Anodized finishes

20、are extra-thick oxide coatings produced by electro- chemical treatment. The thickness of the anodic layer can be varied from 0.05 to 1.5 mils (0.0013-0.038 mm). The anodic layer may be trans- parent or integrally colored; in both porcelain enameled finishes plated finishes laminated finishes cases t

21、he metals natural luster will be visible. Or the anodic layer may be pigmented, dyed or impregnated with a lubricant, a wax or both. Anodizing substantially improves aluminums resistance to weather- ing. When anodized aluminum is to be used architecturally, it is some- times given a clear organic co

22、ating for protection against alkaline build- ing products during construction and to facilitate cleaning afterwards. Anodic layers - due to their alu- minum oxide/hydroxide chemical composition - may also be tailored to enhance wear and abrasion resistance. chemical conversion finishes Chemical conv

23、ersion finishes are coatings generally created by chem- ical means alone. They are thinner and less abrasion resistant than anodic coatings. Most often they are used as a base for paint. Occasionally, conversion coatings are used as final surfaces for prod- ucts and utilitarian structures. Conversio

24、n coating may be clear or colored gold, gray, golden brown, green or blue-green. painted finishes laminate finishes Painted finishes are organic coatings of various kinds applied to the sur- face of aluminum. In the plant, paint is applied over conversion coatings. In the field, paint or clear organ

25、ic coating (iac- quer) may be applied to any weath- ered aluminum surface or to a clean and grease-free aluminum surface after it has been roughened mechan- ically or chemically, or treated with suitable wash primers. Laminate finishes are produced by bonding a thin layer of other metals, wood, clot

26、h, plastic or a combination of these materials (and possibly oth- ers) to the surface of aluminum. The care and cleaning required by the laminate surface is that required by the facing material. As there are dif- ferent laminates in use, cleaning pro- cedures cannot be described here but must be fou

27、nd by careful testing and consultation with the manufac- turer. porcelain enameled finishes Porcelain enameled finishes are ceramic coatings which have been fired permanently onto the surface of the aluminum. Porcelain finishes are very hard, impervious to soils and many acids and alkalies. These fi

28、n- ishes come in many colors, with smooth or textured surfaces. plated finishes Plated finishes are produced by electrodepositing one or more differ- ent metals on aluminum. Nickel, chromium, copper, tin, silver and gold are often used. Sometimes the plated metal is deposited directly onto the alumi

29、num, and sometimes an intermediate metal is used. Aluminum finishes are usually designated by a system of letters and digits devised by The Aluminum Association and used throughout the industry. A full description of this sys- tem may be found in “Designation System for Aluminum Finishes”, pub- lish

30、ed by The Association. 12 for bare aluminum for anodized aluminum for conversion finishes for painted aluminum for porcelain finishes simple finish tests simple finish tests The following tests are suggest- ed as guides for determining the type of finish employed on aluminum. It should be kept in mi

31、nd that test results can be misleading. The use of a pocket magnifier can help in identifying the finish. The tests should be performed on a small area or in an area not of esthetic concern. Consultation with the supplier is the most reliable method of determining the finish. for bare aluminum A ste

32、el needle or similar pointed tool is used to prick the metals surface. If the metal is easily marked and the scratch is no broader than the tools point, the aluminum is “bare”. If the metal is rubbed with a rubber eraser, the metal may lighten in color and the eraser may darken. If the surface is ru

33、bbed with a hard eraser, bare aluminum is often scratched by rubber fillers, while anodized aluminum is perhaps brightened due to cleaning but is not scratched. for anodized aluminum If a clean surface is rubbed with an eraser and neither the color of the metal nor the color of the eraser changes, t

34、he aluminum has been anodized. If either changes, the alu- minum is bare. If the eraser test is not conclu- sive, as it may not be on perfectly clean and bright, bare aluminum, the needle test may be used. Aluminum oxide is hard and glassy. Consider- able force will be necessary to penetrate it. The

35、 scratch will be wider than the needles point, and the sound of the scratch being made will be audible. Anodized aluminum is sometimes given a clear organic coating. This can be detected with a needle or by scratching a small area with a knife-edge. for conversion coatings The eraser test should sho

36、w no change. Penetration by needle point should not be too difficult. Scratch marks will be somewhat broader than the tools point. Some inorganic chrome conversion coatings can be detected by exposing one side of a thin sheet to hot flame, and observ- ing whether a very dark thin residue forms on th

37、e opposite side. for painted aluminum All paint, even the hardest baked on paints, is soft compared to metallic and anodized surfaces. Paints have a plastic, gum-like texture. This can be detected with a needle point. Paints can also be detected destructively by exposing the sur- face to flame, and

38、seeing if thick charred paint ash develops. for porcelain finishes These finishes will resist penetration by needle point almost to the break- ing of the needle itself. These finish- es are very hard. for plated finishes Gold and silver are soft metals and easily scratched; a deep scratch will revea

39、l the pale gray of the base alu- minum, as the precious metal plating is usually very thin. Platings of other metals can often be identified by their non-aluminum color. They also may be harder to penetrate and thicker than gold and silver, but fine slivers can sometimes be removed with a sharp tool

40、. This cannot be done with any of the other finishes except some brittle paints. Chromium plating can be identi- fied by its hardness and silvery bril- liance. Chromium plating tends to be porous and when not maintained, oxygen enters the pores and pro- duces gray specks. Careful observation of the

41、luster can often help differentiate among the common plating metals: silver is very white unless tarnishing black, I3 U for plated finishes chromium has a bluish cast com- pared to aluminum or silver, and nickel has a dark or blackish cast compared to aluminum or silver, even though nickel is usuall

42、y shiny. Comparison with known samples for color will help the beginner. Spot tests from inorganic chemistry texts can help identify specific metals. general tests If available, the use of thickness measurement equipment, such as eddy current testers, can be used to detect the presence or absence of

43、 a wide range of thicker coatings. These include anodizing, paint, porcelain, and metal plating, which are often over 0.1 mils (0.0025 mm) thick. If the device is “zeroed“ onto bare aluminum and tests of the unknown sample demonstrate a sig- nificant thickness, then there is a thicker coating of som

44、e type present, although the exact identity and thick- ness remains unknown without other tests. Conversion coatings are often less than 0.1 mil (0.0025 mm) thick and might not be detected this way. match cleaner make a spot test to be sure watch frequency follow do not mix avoid drips and splashes

45、avoid extreme to finish of cleaning manufacturers cleaners temperatures directions cleaning aluminum a. common sense cleaning rules Caution: Because some cleaning materials can be hazardous to human health, the safety recommen- dations of the cleaner manufacturer should be followed. match cleaner to

46、 finish watch cleaning frequency Where optimum appearance is desired and frequent cleaning is nec- essary, use mild cleaners. Abrasive cleaners can wear away the hardest finish. follow manufacturers directions Mild soap and warm water may be safely applied to any of the alu- minum finishes. But stee

47、l wool, strong acids and abrasive cleaners should never be applied indiscrimi- nately; though in their place strong cleaners, used correctly, are highly effective. Cleaners should not be applied indiscriminately. Varying concentra- tions and temperatures or extending the time to which the finish is

48、exposed to the cleaning agent, all in an effort to speed cleaning, may pro- duce disastrous results. make a spot test to be sure The few moments invested in testing a cleaner on an unobtrusive portion of the finish is good insurance against a major disappointment. Use the same concentration and tech

49、- nique planned for the entire job. Let the cleaner remain in place for the same time. Let it dry and inspect for stains. Test lacquered and painted finishes for softening and possible dissolution. do not mix cleaners The resultant mixture may be harm- ful to aluminum finishes and haz- ardous to the users health. avoid drips and splashes Cleaners harmless to some materi- als may damage other materials upon contact. Remove run-downs as quickly as possible. do not vary cleaner concentration In most instances, increasing or decreasing cleane