Trivalent Chrome Cr(III) development for use in Black Passivates has become necessary in recent years as a result of the European legislation ELV (Directive 2000/53/EC) and further environmental legislations (RoHS and WEEE). The elimination of hazardous substances from coatings has resulted in the ban of hexavalent chrome Cr(VI) containing compounds from corrosion protection layers and forced the industry to convert to trivalent chrome passivates Cr(III).

Effective clear trivalent passivates emerged shortly after the ELV directive. However, it took the electroplating industry longer to develop trivalent black passivates to match the appearance and performance of the old Hexavalent Black Cr(VI) black chromates.

Table 1: Neutral Salt Spray Testing Results for Trivalent Black Passivation
Plating
Type
White (Zn)
Corrosion
Red (Fe)
Corrosion
Customer
Compliance
Zn 96+ 300+ Toyota
TSH 6524G
      General Motors
GMW 3044
ZnFe 240 504 Toyota
TSH 6528G
ZnNi 240 720+ Volkswagen
TL 244
      General Motors
GMW 4205

New products started emerging early in 2008 and by late fall Roy Metal Finishing had completed a comprehensive review of new trivalent black passivates being offered in Europe, Japan and the US. The chemical manufacturers all have new product offerings. As a result, we performed side by side tests to determine which formulation was best for us as an applicator as well as which would best meet the high expectations of our customers. We tested rack and barrel plated trivalent blacks over zinc, zinc iron and zinc nickel, and now offer the best blacks on the market today.

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About Roy Metal Finishing

Roy Metal Finishing is an ISO/TS 16949 and ISO 14001 certified electroplating jobshop specializing in zinc and zinc alloy coatings for the automotive and aerospace industries.

Our two highly automated facilities are located in the beautiful southeast in Greenville, South Carolina on the Interstate 85 corridor between Charlotte, North Carolina and Atlanta, Georgia. This area, once known for textiles, is now home to BMW Manufacturing and 230 other international companies. With over 200 automotive suppliers located in South Carolina and over 1000 automotive suppliers located within 500 miles of Greenville, this area is rapidly becoming known as the new center for automotive commerce.

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Roy Metal Finishing

112 Conestee Road
Greenville, SC 29607
USA
(864) 277-0420
ISO 14001: 2004
ISO/TS 16949: 2002