Peninsula Metal Finishing, Inc.

• Mil-8625
• ASTM B580

Anodizing Alternatives Anodizing is the process of creating a controlled oxide coating on aluminum. A number of types of anodize processes have been developed for various end uses. The more popular types are: Chromic Acid Anodizing Improves corrosion protection Paint base for aircraft and marine parts Mil-A-8625, Type I, SAE-AMS-2470 Sulfuric Acid Anodizing Cosmetic, most specified of the types Ability to be dyed to a wide range of colors Mil-A-8625, Type II, SAE-AMS-2471 (Clear), SAE-AMS-2472(Colored) xx

• MIL32119

Electroless plating does not require the introduction of electrical current into the bath to deposit the plated metal. When metal, or metalized, parts are immersed in the plating bath an autocatalytic reaction occurs between the solution and the surface of the parts. The metal in the solution is then plated onto the part. The primary benefits of this form of plating are even distribution of the plating over the surface of the part, the ability to hold critical dimensions after plating, and corrosion resistance on all plated surfaces. Electroless nickel is relatively hard as plated with a hardness of 40-50 RC, and baking at elevated temperatures will increase this into the range of 65-70 RC. A benefit of the hardness is increased wear resistance. Plating thickness can range up to several thousandths of an inch and is particularly attractive to salvage undersized parts. Phosphorous content can vary with individual plating solutions. The low phosphorous deposits are generally less ductile than high phosphorous deposits. Additionally, the phosphorous content of the electroless nickel and the baking of the nickel to increase hardn

• ASTM633

inc is one of the more popular and cost effective metals to electroplate. It is a durable sacrificial coating that generally receives a supplementary chromate coating that provides the majority of the corrosion resistance. Maximum thickness is normally held to 1½ thousandths (.0015) due to undesirable deposit characteristics beyond that thickness. Job shops generally offer rack zinc plating and barrel zinc plating with a number of chromate choices, including clear (silver), yellow, black, olive drab. Part size as well as production capabilities are dictated by tank sizes, weight restrictions, and whether the plating lines are hand or hoist operated, or automated. Peninsula Metal Finishing, Inc., utilizes a dual hoist plating line that is capable of rack and barrel operation for bulk zinc plating. The current zinc specification generally used is ASTM-B-633. The military specification QQ-Z-325 that remains on older prints was cancelled in 1982 and superceded with the ASTM-B-633.

Phosphate coatings consist of crystalline, non-reflective, water insoluble metal phosphates that are very adherent to the base metal. Phosphate coatings are measured by coating weights such as gm2 or mgft2. They can be associated in three main categories: ZINC PHOSPHATE Heavy zinc phosphate that has the ability to retain rust inhibiting oils, preservatives, or other specified finishes. MIL-DTL-16232, Type Z Lighter zinc phosphate has a smoother crystal structure and is normally not oiled as it is used as a base for paint. DOD-DTL-16232, Type Z TT-C-490, Various Types and Methods DOD-P-50002, Type Z

• AMS2408

Tin plating has good electrical conductivity and is utilized on parts that require soldering, to increase anti-galling properties, for food containers as it is non-toxic, and for decorative or corrosion protection in a protected environment.