WO2000005433A1

WO2000005433A1 - Method of inhibiting darkening, blackening or tarnishing of aluminium and aluminium alloys and compositions therefore

Info

Publication number: WO2000005433A1
Application number: PCT/US1999/016504
Authority: WO
Inventors: David C. Silverman; Timothy K. Hirzel
Original assignee: Solutia Inc.
Priority date: 1998-07-23
Filing date: 1999-07-21
Publication date: 2000-02-03
Also published as: AU5119099A

Abstract

There is disclosed a method of inhibiting darkening, blackening or tarnishing of aluminium and aluminium alloys comprising contacting an aluminium alloy with a fluid composition containing a composition in an amount effective to inhibit darkening, blackening or tarnishing of the surface of the aluminium or aluminium alloy at an effective pH, and compositions therefore. Also disclosed are aqueous metal working fluid compositions containing the compositions of the invention.

Description

TITLE OF THE INVENTION

METHOD OF INHIBITING DARKENING, BLACKENING OR TARNISHING OF ALUMINIUM AND ALUMINIUM ALLOYS AND COMPOSITIONS THEREFORE

CROSS-REFERENCE TO RELATED APPLICATIONS (NOT APPLICABLE)

STATEMENT REGARDING FEDERALLY SPONSORED 10 RESEARCH OR DEVELOPMENT

(NOT APPLICABLE)

BACKGROUND OF THE INVENTION

15 This invention relates to a method of cleaning aluminum and aluminum alloys and the metal cleaning compositions therefor. This invention further relates to aqueous metal working compositions containing the metal cleaning compositions of this invention.

Aluminum and aluminum alloys find use in the transportation field. In

20 aircraft, heat treatable alloys with high strength and toughness are used extensively in engines, frames, skin sheet and landing gear. In automobiles, aluminum alloys are used for wheels, air conditioners, intake manifolds, water pumps and automatic transmissions. Body panels, radiators, oil coolers and engine blocks are also made of aluminum to reduce weight and increase fuel economy. In marine service, Al-Mg and

25 Al-Mg-Si alloys are used for canoes, pleasure boat hulls, fishing boats, and tanks for liquified natural gas.

Aluminum and aluminum alloys can be cleaned using solvent cleaning, alkaline cleaners, organic acids, nitric acid, and phosphoric acid with chromate. Aluminum and aluminum alloys can also be cleaned by pickling using mixtures of

30 sulfuric acid and chromic acid, phosphoric acid, and alkaline solutions, e.g. aqueous caustic soda baths Solvent cleaning and pickling are undesirable due to the required recovery of the solvent(s) or cleaner(s) used.

It has now been surprisingly discovered that the amido acids or salts thereof of the invention are effective in cleaning, 1 e inhibiting darkening, blackening or tarnishing of aluminum and aluminum alloy surfaces when exposed to fluids containing these compounds The metal cleaning effect is seen in aqueous compositions which are formulated with deionized water or soft water or water of comparable quality or similar quality These compositions include in particular aqueous metal working compositions formulated with water of comparable or similar quality.

BRIEF SUMMARY OF THE INVENTION

It is an object of the invention to provide a method for cleaning the surface of aluminum and aluminum alloys exposed to aqueous compositions. It is a further object of the invention to provide metal cleaning compositions useful in cleaning aluminum and aluminum alloys. It is a still further object of the invention to provide aqueous metal working fluid compositions containing the metal cleaning compositions of the invention which are particularly useful in the metal working of magnesium, aluminum and aluminum alloys. Such a metalworking fluid of this invention could be used to circumvent an intermediate wash step of the aluminum and aluminum alloys between the metal working process and any subsequent treatment operation, e.g coating

According to the invention, a method of cleaning the surface of aluminum and aluminum alloys is provided which comprises contacting an aluminum or aluminum alloy with a fluid composition containing a metal cleaning composition in an amount effective to clean the surface of the aluminum or aluminum alloy at an effective pH, wherein the metal cleaning composition compπses at least one amido acid or salt thereof having the formula

wherein R is an alkyl or alkenyl group having about 7 to about 21 carbon atoms, provided that R contains a linear chain of at least 7 carbon atoms; M and M' are cations independently selected from hydrogen, alkali metal or amine salts, and m and n independently represent an integer from 0 to 2

Further according to the invention, a composition useful for cleaning aluminum and aluminum alloys is provided which compπses a concentrated solution of at least one amido acid or salt thereof having the formula

in an amount effective to clean the surface of aluminum and aluminum alloys when the composition is diluted with water and contacted with the aluminum and aluminum alloys Still further according to the invention, a metal working composition is provided which compπses water and a metal cleaning composition in an amount effective to clean the surface of aluminum and aluminum alloys at an effective pH, wherein the metal cleaning composition is as defined above. The metal working compositions of the invention optionally contain a polyaspartic polymer in the acid, salt or amide form thereof. Such polyaspartic polymer containing metal working fluids are descπbed in U.S. Patents 5,401,428 which issued to Dennis J. Kalota, et al on March 28, 1995 and 5,616,544, which issued to Dennis J. Kalota, et al On Apπl 1, 1997, both of which are incorporated by reference herein in their entirety

BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWING

(NOT APPLICABLE) DETAILED DESCRIPTION OF THE INVENTION

A first embodiment of the invention relates to a method of cleaning the surface of aluminum and aluminum alloys comprising contacting an aluminum or aluminum alloy with a fluid composition containing a metal cleaning composition in an amount effective to clean the surface of the aluminum or aluminum alloy at an effective pH, wherein the metal cleaning composition comprises at least one amido acid or salt thereof having the formula:

As used herein, "cleaning" means inhibiting formation of tarnishing, darkening or blackening of the metal surface and "to clean" means to inhibit formation of tarnishing, darkening or blackening of the metal surface. In particular, formation of oxides or hydroxides on the surface of the metal is inhibited by use of the metal cleaning composition of the invention.

The amido acids or salts thereof of the invention are represented by the formula:

wherein R is an alkyl or alkenyl group having about 7 to about 21 carbon atoms, provided that R contains a linear chain of at least 7 carbon atoms; M and M' are cations independently selected from hydrogen, alkali metal or amine salts, and m and n independently represent an integer from 0 to 2. Suitable amine salts include the water soluble cations derived from ammonia and any amine-containing organic compound. Examples of suitable amine salts include, but are not limited to, cations represented by the formula (R') N⁺ wherein each R' is independently hydrogen, alkyl having 1-10 carbon atoms, aminoalkyl having 2-10 carbon atoms, or hydroxyalkyl having 2-10 carbon atoms. When each of R' is hydrogen, the cation is ammonium, i e. NlV^". When at least one R' is other than hydrogen, (R') N^~ can be a pπmary, secondary or tertiary ammonium, or a quaternary ammonium ion Preferably, the amine salt is tnethanolammonium or ammonium. Preferably, m is 0 and n is 1 or 2, and at least one of M and M' is other than hydrogen More preferably, m is 0 and n is 2. When at least one of M and M' is other than hydrogen, it is preferably an alkali metal or tn(hydroxyalkyl)ammonιum, and more preferably sodium, potassium or tnethanolammonium The number of carbon atoms in R is preferably about 8 to about 17 carbon atoms, and more preferably about 9 to about 17 carbon atoms.

Examples of the amido acids or salts thereof include, but are not limited to, N-cocoyl-L-glutamic acid, sodium N-cocoyl-L-glutamate, tnethanolammonium N-cocoyl-L-glutamate, tnethanolammonium N-lauroyl-L- glutamate, sodium N-lauroyl-L-glutamate, N-stearoyl-L-glutamic acid, sodium N- stearoyl-L-glutamate, N-cocoyl-L-aspartic acid, sodium N-cocoyl-L-aspartate, tnethanolammonium N-cocoyl-L-aspartate, tnethanolammonium N-lauroyl-L- aspartate, sodium N-lauroyl-L-aspartate, N-stearoyl-L-aspartic acid and sodium N- stearoyl-L-aspartate The currently preferred amido acids or salts thereof are N- cocoyl-L-glutamic acid. N-lauroyl-L-glutamic acid, and the salts thereof.

The metal cleaning composition of the invention can be diluted with a diluent, preferably water of the aforementioned soft or deiomzed or similar or comparable quality to prepare the fluid composition used in contact with the aluminum or aluminum alloys. Upon dilution of the metal cleaning composition, the amido acid or salt thereof is present in the resultant fluid composition in an amount effective to clean the aluminum and aluminum alloys. The effective amount of the metal cleaning composition may depend on the number of carbon atoms and amount of branching in the R group of the amido acid or salt thereof, and will be readily apparent to one skilled in the art based on the teachings of the instant invention. Generally, the amido acid or salt thereof is present in the dilute fluid composition at a level of at least 0.05 wt % The upper level of amido acid or salt thereof is readily determined by one skilled in the art and is that amount which is soluble in the fluid composition, i.e diluted metal cleaning composition Preferablv. the amido acid or salt thereol is present in the fluid composition at a level in the range of about 0 075 wt % to about 10 wt %, and more preferablv 0 1 wt. % to about 2 wt. %

As used herein, the effective pH of the fluid composition is that pH in which cleaning of the aluminum or aluminum alloys is achieved. The preferred pH range of the fluid composition is about 7 to about 9.5.

The metal cleaning compositions of the invention are useful in cleaning aluminum and aluminum alloys. Both cast and wrought aluminum alloys may be employed in this invention. Aluminum is known to be intentionally alloyed with as many as five or six other elements to impart desired qualities. Aluminum alloys can contain about 10 to 15 elements other than aluminum. See ASM Handbook. Volume 2, 10th Edition, 1990 which is incorporated herein by reference in its entirety

A second embodiment of the invention relates to a composition useful for cleaning aluminum and aluminum alloys compnsing a concentrated solution of at least one amido acid or salt thereof having the formula:

in an amount effective to clean aluminum and aluminum alloys when said composition is diluted with water and contacted with the aluminum and aluminum alloys, wherein R is an alkyl or alkenyl group having about 7 to about 21 carbon atoms, provided that R contains a linear chain of at least 7 carbon atoms; M and M' are cations independently selected from hydrogen, alkali metal or amine salts, and m and n independently represent an integer from 0 to 2.

Generally, the amount of amido acid or salt thereof present in the concentrated solution is at least about 0 75 wt %. The upper level of amido acid or salt thereof is readily determined by one skilled in the art and is that amount which is soluble in the concentrated solution composition It is well known in the art that other additives such as coupling agents, hydrotropes and emulsifiers, e.g. polyalkylene glycols and denvatives thereof or short chain fatty acids, can be used to increase the solubilities in aqueous solutions. Such additives can be used in the concentrated solution composition of the invention to increase the solubility of the amido acids or salts thereof Preferably, the amount of amido acid or salt thereof present in the concentrated solution is about 1 1 wt % to about 30 wt % When the concentrated solution is diluted, such as with water, the concentration of amido acid or salt thereof is as disclosed above for use in the first embodiment of the invention

The third embodiment of the invention is a metal working composition compnsing water of the aforementioned deionized or soft quality or of similar or comparable quality and a metal cleaning composition in an amount effective to clean aluminum and aluminum alloys at an effective pH, wherein said metal cleaning composition composes at least one amido acid or salt thereof having the formula-

wherein R is an alkyl or alkenyl group having about 7 to about 21 carbon atoms, provided that R contains a linear chain of at least 7 carbon atoms; M and M' are cations independently selected from hydrogen, alkali metal or amine salts, and m and n independently represent an integer from 0 to 2.

Generally, the amido acid or salt thereof is present in the metal working composition at a level of at least 0.05 wt. % The upper level of amido acid or salt thereof is readily determined by one skilled in the art and is that amount which is soluble in the metal working composition. Preferably, the amido acid or salt thereof is present in the metal working composition at a level in the range of about 0.075 wt % to about 10 wt. %, and more preferably about 0.1 wt % to about 2 wt. %.

The metal working composition of the invention optionally contains a polyaspartic polymer in the acid, salt or amide form thereof A typical concentation of of the polyaspartic polymer in a fluid concentrate is in the range of from about 0.5 weight. % to about 70 weight %, and preferably from about 3 wt % to about 50 wt. %, of the metal working composition. The polyaspartic polymers for use in the invention are descnbed in U S 5,616,544 supra, which is incorporated herein in its entirety by reference The metal working compositions of the invention are useful in vanous metal working operations including, but not limited to, cutting, threading, bending, gnnding, broaching, tapping, planing, gear shaping, reaming, deep hole dπlling/gundnlhng, dnlling, bonng, hobbing, milling, turning, sawing and shaping of vanous ferrous and non-ferrous metals The metal working compositions of the invention are useful in the vanous metal working operations noted above with any number of types of metals. In particular, they are useful in working ferrous metals such as iron, steel (carbon steel and low alloy carbon steel), and stainless steel Non- ferrous metals which can be worked with metal working compositions of this invention are titanium, zirconium, copper, brass, nickel, cobalt, magnesium, aluminum and alloys thereof. Particularly preferred non-ferrous metals are magnesium, aluminum and alloys thereof Such metals are safely worked with lubncity supplied by the aqueous metal working fluids of this invention.

One or more vanous additives may be employed m the metal working compositions of the invention to enhance or contnbute properties which enable broader function or better performance with respect to the use of the compositions in metal working applications. The types of additives include corrosion inhibitors, oxidation inhibitors, antifoam agents, biocides, emulsification agents, viscosity modifiers, coupling agents, lubncants, residue modifiers, pH buffers, wetting agents, and antiwear and antifriction agents.

Lubncants may be of several kinds, including simple, hydrodynamic, boundary, and extreme pressure lubncants A particularly useful class of lubncants are the polycarboxy c acids or salts thereof having two or more carboxyhc acid groups Examples of applicable polycarboxyhc acid or salts thereof include, but are not limited to, butanetetracarboxylic acid, succinic acid, oxalic acid, malonic acid, glutanc acid, adipic acid, propanetncarboxyhc acid, hexanetncarboxy c acid, maleic acid, fumanc acid, citπc acid, the salts thereof, and the like. The preferred polycarboxyhc acids are butane tetracarboxy c acid and salts thereof, and succinic acid and salts thereof. Additives for imparting hydrodynamic or boundary lubricity may be employed in this invention, including but not limited to long-chain alkyl carboxylic acids, salts, esters or amides thereof, polyalkylene glycols, and polyalkylene glycol derivatives of long-chain alkyl alcohols, acids or amines, mixtures thereof and the like. Corrosion inhibitors for a variety of metals can be employed in the metal working compositions of the invention. Examples of corrosion inhibitors include, but are not limited to, alkanolamines, aryltriazoles, 3-amino-l,2,4-triazole, and the like.

The metal working compositions of the invention preferably comprise at least one of an aryltriazole having the formula

or 3-amino-l,2,4-triazole; wherein Y is an alkyl group having 1 to about 6 carbon atoms or -COO^"M⁺ , M" is hydrogen or an alkali metal, and p is an integer from 0 to 4.

Preferably, M" is hydrogen, p is 0 or 1 and Y is methyl, ethyl or butyl.

The aryltriazole or 3-amino-l,2,4-triazole can be used in conjunction with the required amido acid or salt thereof to impart synergistic corrosion inhibition properties with respect to ferrous metals. When utilized in the metal working compositions of the invention, the aryl triazole or 3-amino-l,2,4-triazole compound is present in an amount (when used in conjunction with the amido acids or salts thereof of the invention) effective to inhibit corrosion of ferrous metals; preferably present in an amount of at least about 0.04 wt. % of the metal working composition; and more preferably present in an amount of about 0.05 wt. % to about 0.75 wt. .

The aryltriazoles of the invention are represented by the formula

wherein Y is an alkyl group having 1 to about 6 carbon atoms or -COO^"M⁺ , M" is hydrogen or an alkali metal, and p is an integer from 0 to 4. Preferably, M" is hydrogen, p is 0 or 1 and Y is methyl, ethyl or butyl.

Examples of the aryltriazoles include, but are not limited to, benzotriazole, tolyltriazole, 5-ethylbenzotriazole and 5-butylbenzotriazole. The currently preferred aryltriazoles are benzotriazole and tolyltriazole.

Without being bound by theory, it is believed that the alkanolamine compounds also function as pH stabilizers and residue enhancers (i.e. prevention of formation of a hard residue on drying) and include, but are not limited to, triethanolamine, l,3-Bis[tris(hydroxymethyl)-methylamino]propane, isopropanolamine and the like.

Biocides that can be used in the metal working compositions of the invention include those conventional biocides that are known in the art. Examples of biocides include, but are not limited to, l,2-benzisothiazolin-3-one known as Proxel, poly(oxy- 1 ,2-ethanediyl(dimethylimino)- 1 ,2-ethanediyl(dimethylimino)- 1 ,2- ethanediyl dichloride) known as Busan 77, 2-methyl-4-isothiazolin-3-one (known as Kordek) and 2-n-octyl-4-isothiazolin-3-one (known as Kathon 893), mixtures thereof and the like.

EXAMPLES

Example 1 A metal working composition was examined for its ability to stain aluminum as a function of source of water used for preparation and dilution. The formulation contained 6.32 wt.% of mono sodium N-stearoly glutamate. Small metal specimens (corrosion coupons) of Al 2024, Al 6061, and Al 7075 were immersed in various metal working compositions for one week at room temperature. Prior to immersion, the coupons were rinsed with acetone followed by methanol. They were placed on a dry paper towel. Gloves were worn at all times to prevent contamintion of the clean surface. The coupons were suspended in the solution by means of a glass and stored for about 8 days. The coupons were then examined for blackening or other type of staining. The results are shown in Table I.

TABLE I ALUMINUM STAINING RESULTS

Example 2

Solution Preparation

The following were studied for their ability to clean aluminum surfaces:

1. monosodium N-stearoyl glutamate at 0.42 wt%, pH = 8.5

2. monosodium N-stearoyl glutamate at 1.44 wt%, pH = 8.5 3. monosodium N-cocoyl glutamate at 0.16 wt%, pH = 8.5

4. monosodium N-cocoyl glutamate at 0.64 wt%, pH = 8.5

5. monosodium N-cocoyl glutamate at 1.28 wt%, pH = 8.5

6. monosodium N-cocoyl glutamate at 9.60 wt , pH = 8.5

7. Triethanolamine at about 0.5 wt , pH = 9.5

For each solution, 500grams was prepared. The appropriate amount of

acyl glutamate to be examined was weighed into a 1 liter beaker. Then about 400 ml

of deionized water was added and the combined weight was recorded. Then

triethanolamine (TEA) was added to bring the pH up to 8.5. The solution was again weighed and the amount of TEA recorded. Then more deionized water was added to

bring the total weight up to 500.00g. An exception is the solutions for TEA plus

water. In that case, 500 ml of deionized water was added to a beaker and TEA was

added to bring the pH up to around 8.5 - 9.0. Then TEA diluted in deionized water

was added to bring the pH up to 9.5.

The procedure for immersion tests was:

1. The aluminum (7075-T6) corrosion coupons were rinsed with acetone followed by methanol. The coupon was placed on a clean paper towel to dry. Gloves were worn at all times to prevent contamination of the clean surface.

2. The dry coupons were weighed on an analytical balance (O.OOOlg).

3. The coupons were suspended in the appropriate solutions by means of a glass string that had been burned to remove resins. 4. After the appropnate immersion time (approximately one month) the coupons were removed from the solutions. They were examined for staining and blackening.

5. An electnc eraser was used to remove any blackening that could be easily removed.

6. The coupons were re-weighed and corrosion rates calculated form the mass loss and exposure time. Uniform corrosion was assumed for the calculation.

Table U

Mass Loss Study for Aluminum 7075-T6 in the Presence of Acyl Glutamates

Thus, it is apparent that there has been provided, in accordance with the instant invention, a composition and method of use that fully satisfies the

objects and advantages set forth herein above. While the invention has been descnbed with respect to vanous specific examples and embodiments thereof,

it is understood that the invention is not limited thereto and many alternatives,

modifications and vanations will be apparent to those skilled in the art in light

of the foregoing descπption. Accordingly, it is intended to embrace all such

alternatives, modifications and vanations as fall within the spint and broad

scope of the invention.

Claims

CLAIM OR CLAIMSTHAT WHICH IS CLAIMED IS

1. A method of cleaning the surface of aluminum and aluminum alloys compnsing- contacting an aluminum or aluminum alloy with a fluid composition containing a metal cleaning composition in an amount effective to clean the surface of said aluminum or aluminum alloy at an effective pH, wherein the metal cleaning composition compnses at least one amido acid or salt thereof having the formula

2. The method of claim 1 wherein said amido acid or salt thereof is present in said fluid composition in an amount of at least 0.05 wt. %.

3. The method of claim 2 wherein said amido acid or salt thereof is present in said fluid composition in a range of about 0.075 wt. % to about 10 wt. %.

4. The method of claim 1 wherein R is an alkyl or alkenyl group having about 8 to about 17 carbon atoms

5 The method of claim 4 wherein m is 0 and n is 1 or 2

6. The method of claim 5 wherein M and M' are independently hydrogen, alkali metal or tn(hydroxyalkyl)ammon╬╣um.

7. The method of claim 6 wherein at least one of M and M' is sodium, potassium or triethanolammonium.

8. The method of claim 1 wherein the pH is in the range of about 7 to about 9.5.

9. The method of claim 1 in which said aluminum alloys are wrought aluminum alloys.

10. The method of claim 1 wherein said aluminum alloys are cast aluminum alloys.

11. A composition useful for cleaning aluminum and aluminum alloys comprising a concentrated solution of at least one amido acid or salt thereof having the formula

in an amount effective to clean aluminum and aluminum alloys when said composition is diluted with water and contacted with said aluminum and aluminum alloys, wherein R is an alkyl or alkenyl group having about 7 to about 21 carbon atoms, provided that R contains a linear chain of at least 7 carbon atoms; M and M' are cations independently selected from hydrogen, alkali metal or amine salts, and m and n independently represent an integer from 0 to 2.

12. The composition of claim 11 wherein the amido acid and salts thereof are present in an amount of at least 0.75 wt. %.

13 The composition of claim 12 wherein the said amido acid or salt thereof is present in a range of about 1.1 wt. % to about 30 wt. %.

14. The composition of claim 1 1 wherein R is an alkyl or alkenyl group having about 8 to about 17 carbon atoms.

15. The composition of claim 14 wherein m is 0 and n is 1 or 2.

16. The composition of claim 15 wherein M and M' are independently hydrogen, alkali metal or trihydroxyalkylammonium.

17. The composition of claim 16 wherein at least one of M and M' is sodium, potassium or triethanolamrnonium.

18. The composition of claim 11 further comprising water in an amount wherein said amido acid or salt thereof is present in an amount of at least 0.05 wt. %.

19. The composition of claim 18 wherein said amido acid or salt thereof is present in a range of about 0.075 wt. % to about 10 wt. %.

20. A metal working composition comprising water and a metal cleaning composition in an amount effective to clean aluminum and aluminum alloys at an effective pH, wherein said metal cleaning composition comprises at least one amido acid or salt thereof having the formula

21. The composition of claim 20 wherein the amido acid and salts thereof are present in an amount of at least 0.05 wt. %.

22. The composition of claim 21 wherein the said amido acid or salt thereof is present in a range of about 0.075 wt. % to about 10 wt. %.

23. The composition of claim 20 wherein R is an alkyl or alkenyl group having about 8 to about 17 carbon atoms.

24. The composition of claim 23 wherein m is 0 and n is 1 or 2.

25. The composition of claim 24 wherein M and M' are independently hydrogen, alkali metal or tri(hydroxyalkyl)ammonium.

26. The composition of claim 25 wherein at least one of M and M' is sodium, potassium or triethanolammonium.

27. The composition of claim 20 further comprising an alkanolamine.

28. The composition of claim 27 wherein said alkanolamine is selected from triethanolamine.

29. The composition of claim 27 further comprising a biocide.

30. The composition of claim 29 wherein said biocide is selected from l,2-benzisothiazolin-3-one, poly(oxy-l,2-ethanediyl(dimethylimino)-l,2- ethanediyl(dimethylimino)-l,2-ethanediyl dichloride) , 2-Methyl-4-isothiazol-in-3- one, 2-n-Octyl-4-isothiazolin-3-one and mixtures thereof.

31. The composition of claim 29 further comprising a polycarboxyhc acid.

32. The composition of claim 31 wherein said polycarboxyhc acid is selected from butane tetracarboxylic acid and salts thereof, succinic acid and salts thereof, and mixtures thereof.

33. The composition of claim 31 further comprising at least one of an aryltriazole having the formula

or 3-amino-l,2,4-triazole; wherein Y is an alkyl group having 1 to about 6 carbon atoms or -COO^"M⁺ , M" is hydrogen or an alkali metal, and p is an integer from 0 to 4; wherein said aryltriazole or 3-amino-l,2,4-triazole is present in an amount such that the combination of said aryltriazole or 3-amino-l,2,4-triazole with said amido acid or salt thereof is effective to inhibit ferrous metal corrosion.

34. The composition of claim 20 further comprising a polyaspartic polymer in the acid, salt or amide form thereof wherein the concentration of said polymer is in the range of from about 0.5 wt. % to about 70 wt. % of said composition.

35. The composition of claim 20 wherein the pH is in the range of about 7 to about 9.5.

36. A metal working composition comprising:

(a) water, (b) a metal cleaning composition in an amount effective to clean aluminum and aluminum alloys at an effective pH, wherein said metal cleaning composition compnses at least one amido acid or salt thereof having the formula

wherein R is an alkyl or alkenyl group having about 7 to about 21 carbon atoms, provided that R contains a linear chain of at least 7 carbon atoms; M and M' are cations independently selected from hydrogen, alkali metal or amine salts, and m and n independently represent an integer from 0 to 2,

(c) at least one of an aryltriazole having the formula

or 3-amino-l,2,4-triazole; wherein Y is an alkyl group having 1 to about 6 carbon atoms or -COO^"M⁺ , M" is hydrogen or an alkali metal, and p is an integer from 0 to 4; wherein said aryltriazole or 3-amino-l,2,4-triazole is present in an amount such that the combination of said aryltriazole or 3-amino-l,2,4-triazole with said amido acid or salt thereof is effective to inhibit ferrous metal corrosion,

(d) an alkanolamine, and

(e) a biocide.

37. The composition of claim 36 further comprising: (0 a polycarboxyhc acid.

38. A method of metal working aluminum or aluminum alloys thereof using the metal working composition of claim 20.