Mildtl81706a 18 february 2002 superseding milc81706. What ams spec is equivalent to milc5541 type 1 grade c, class 3. The specification is approved for use by all departments and agencies of the united states. These coatings can modify the surface of the aluminum material for improved corrosion resistance, electrical. The second document milqpl81706 governs materials qualified for use under mildtl81706. Aluminum chromate conversion coatings, often referred to as chemical film or under the trade names. The area to be touched up shall be not greater than 5 percent. The third document milc5541 specifies the performance characteristics of chemical conversion films. Chem corrosion resistant coating part number mildtl81706 nsn 8030000650957. Chem film, sometimes called by the trade names alodine or iridite, is a. Mildtl5541f is a detailed spec for a chemical conversion coating over aluminum. Hard anodize mila8625 type iii class 1 ams2468 ams2469 astm b580 type a 7. Because class 3 coatings are thinner they are more susceptible to corrosion than class 1a.
Class 3 however, also maintains electrical conductivity. Henkel bonderite mcr 1201 aero light metals conversion coating. Mil dtl 81706 chemical conversion materials for coating aluminum and aluminum alloys. Milc5541, class i a, 3 mildtl5541 type i, ii class ia, 3 ams 2473 type i, class ia coating yellow in appearance maximum corrosion resistance type i, class 3 coating clear or yellow in. Henkel alodine 1200s conversion coating mildtl81706. Difference between milc5541e, amsc5541, and mildtl541f. The trivalent chromium process tcp provides a non hexavalent chrome coating compliant with rohs. Class 3 chemical conversion coatings provide a corrosion preventive film for electrical and electronic applications where lower resistant contacts, relative to class 1a coatings, and anodic coatings in accordance with mil a8625, are required. Mil mildtl5541f chemical conversion coatings on aluminum and aluminum alloys superseding milc5541e standard by military specifications and standards, 07112006. Chem film per mildtl5541 class 3 is electrically conductive. Milc81706 and been accepted for listing on the applicable qualified products.
Mildtl5541 chemical conversion coatings on aluminum and aluminum alloys. As established by mildtl5541, both class 1a and class 3 refer to coatings that offer increased corrosion resistance and adhesive properties. Mildtl5541f chemical conversion coatings on aluminum. The current specification 2009 is mildtl5541f, which superseded milc5541e in july 2006. Surtec 650 is a rohs, reach compliant and qpl approved liquid chemical used to form a protective conversion coating on aluminum surfaces without the use of hexavalent chromium. Type i, class 1a, form ii, method b corcoat msp 1 3 nawcadlke ltr 4120 ser 41k200b1203371 dtd 01 nov 1994 4s1q3 b green until. Mildtl81706b 25 october 2004 superseding mildtl81706a 18 february 2002 detail specification chemical conversion materials for coating aluminum and aluminum. Milc5541 link is to free spec at defense logistics agency, dla. First, we highly recommend using an allpurpose, nonetch lightmetal cleaner. Mildtl5541 type ii, class 1a and class 3 rohs compliant astm b921 class 1a and class 3 rohs compliant we are an. Aluminum chromate conversion coatings per milc5541 mildtl5541 and. Alodine henkel touchnprep coating your worldwide partner. In a type i coating, the chemical composition contains hexavalent chrome.
Mildtl5541 chemical conversion coatings on aluminum. Mildtl81706b 5 requirement for class 1a, form vi, method d materials only. This film typically appears to be gold or brown in color, but in some cases. Chemical film coatings are gelatinous films which provide some sort of a barrier medium to retard corrosion on aluminum surfaces and enhance adhesion of subsequent coatings such as paints and. Types there are two types of coating as specified in mildtl81706b and mildtl5541f.
Anochem tcp meets and exceeds the following requirements. One side of the part is to be processed per milc 5541, class 1a, then primed. In addition to the coating or coating thickness see 6. Class 3 chemical conversion coatings provide a corrosion preventive film for electrical and electronic applications where lower resistant contacts, relative to class 1a coatings, and anodic. Mildtl5541f chemical conversion coatings on aluminum and. Mildtl5541 is a military specification related to conversion coatings. Mildtl81706 milc5541 class 3 rohs thermalloy milc5541 astm b 117 citizen aavid thermalloy c554 aavid catalog text. An nsn, although displayed or written as a continuous string of digits, consists of two.
Currently, only the trivalent chromate formulation developed by navair is listed in the mil dtl 81706 link is to free spec at defense logistics agency, dla. Class 3 clear or yellow for protection against corrosion where low electrical resistance is required. Nonhexavalent chemical conversion films on aluminum. How to pass mildtl5541f for aluminum products finishing. The damaged areas shall be touched up with mildtl81706 material approved on qpl81706 for the applicable type, class, form, and method. Iridite milc5541 mildtl5541 type i yellow type ii clear ams2473 astm. Aluminum chromate conversion coating advanced plating. The trivalent chromium process tcp provides a non hexavalent chrome coating compliant with rohs, elv and weee directives. Difference between milc5541e, amsc5541, and mildtl. We offer an rohscompliant clear trivalent chromium process that is free from hexavalent chromium and complies with the requirements of mildtl5541f class 3.
There are definitely a couple of tricks to passing mildtl5541f, type ii, class 1a for al 2024, and they apply to type i, also. Provides protection against corrosion where low electrical resistance is. Mildtl81706 covers the requirements for the chemical materials used in the formation of conversion coatings by the reaction of the material and the surfaces of aluminum and aluminum alloys. Class 1a for maximum protection against corrosion, painted or unpainted. Milc 5541 link is to free spec at defense logistics agency, dla.
Aluminum chromate conversion coatings, often referred to as chemical film or. Electrolurgy performs chem film to mildtl5541 for aerospace and general industry in irvine, ca. Typical contact resistance of class 3 aluminum chromate conversion coatings. Chromate conversion coating capabilities milc5541e. Optimally usable for the electronics industry due to low surface resistance products mildtl81706 chemical conversion materials for coating aluminum and aluminum alloys this specification covers chemical conversion materials used in the formation of coatings by. The military specification referred to as mildtl5541, military specification, chemical. A national stock number nsn is a thirteen digit number uniquely identifying a single government part designation. Iridite chromate conversion coating finish milc5541. Mildtl81706 chem corrosion resistant coating images. Chem film chromate conversion coatings electrolurgy. At the end of 168 hours of exposure to the 5 percent salt spray. Chemical conversion coatings on aluminum plating per mil dtl 5541 and milc 5541 conversion coatings for aluminum meets requirements of military specifications mil dtl 5541 specifications aluminum alloys and coatings benefit from additional protective features of conversion coatings.
Part number milc5541 including related part numbers and nsn starting at page 1. Touchnprep alodine pen implementation at boeing st. Henkel bonderite aero chromate coating mcr 1201 skygeek. We are nadcap certified, as9100 c and itar registered. The military specification referred to as mildtl5541, military specification, chemical conversion coatings on aluminum and aluminum alloys covers chemical conversion coatings formed by the. Here is a quote from mildtl5541f materials qualified under mildtl81706 produce coatings that range in color from clearcolorless to iridescent yellow, brown, gray, or blue. Class 3 for protection against corrosion where low electrical. Mil dtl 81706b 25 october 2004 superseding mil dtl 81706a 18 february 2002 detail specification chemical conversion materials for coating aluminum and aluminum alloys this specification is approved for use by all departments and agencies of the department of defense. I agree, ted the biggest difference between milc 5541e and mil dtl 5541f is that the buyer can ask for a type ii coating which will contain no hexavalent chromium.