Cr(VI)-free Conversion Coatings

In a subsequent treatment step, the zinc coating is passivated with a Cr(VI)-free conversion coating. This protects the zinc from "white rust". Depending on the appearance and corrosion protection required, various colors of passivate coatings can be offered. For automotive applications Atotech supplies passivation products for clear, blue or black coatings on zinc and zinc alloys.

 

Process

Features & Benefits

IMDS

Iridescent Thick film passivates 

EcoTri®

Thick-film passivation for zinc and zinc alloy layers

  • Completely free of Cr(VI) and fluoride
  • Produces green-red iridescent passivate layers
  • Suitable for rack and barrel plating

900896

EcoTri® HC

EcoTri® HC is a thick-film passivation developed for the use on zinc coatings produced in barrel applications. Especially when heat treatment is required prior to corrosion testing (e.g. 1 hour at 120 °C, 2 hours at 180 °C, 24 hours at 120 °C) the corrosion protection is excellent

900896

EcoTri® HC2

High quality thick-film passivate for zinc and zinc alloy layers

  • Completely free of Cr(VI) and complexing agents
  • Produces green-red iridescent passivate layers on all kind of zinc surfaces with excellent corrosion protection comparable to yellow chromates even with heat treatment required
  • Suitable for rack and barrel plating
  • Easy to waste treat

900896

EcoTri® LT

Low temperature thick film passivate for all kind of zinc and zinc alloy layers

  • Produces green-red iridescent passivate layers with excellent corrosion protection
  • Suitable for rack and barrel plating

900896

Tridur® Zn I

Thick-film iridescent passivation for zinc

  • Produces yellowish to red-green iridescent passivation films
  • Can be used for rack as well as barrel plating

900924

Pasigal H

Iridescent thick film passivate for all kinds of zinc surfaces with very good corrosion protection

  • Completely free of Cr(VI) and complexing agents
  • Easy to waste treat

900924

Clear

Tridur® ZnB
with Tridur® Enhancer

Tridur® Zn B with Tridur® Enhancer used in combination with Corrosil® Plus 501L, produces a clear finish over zinc that can meet the corrosion and requirements of Ford S449

  • Developed especially for the fastener industry
  • Achieves high corrosion resistance at room temperature
  • Ideal for stringent tension requirements

900924

Tridur® ZnNi Clear

Tridur® ZnNi Clear is a transparent, one component liquid passivate based on trivalent chromium for zinc-nickel layers. It is possible to deposit Cr(VI)-free transparent to slightly iridescent coatings on zinc-nickel surfaces with a nickel content of 12 - 15%

  • Easy to handle, control and wastewater treat
  • Can be used for rack and barrel plating
  • High corrosion resistance is being achieved

3641289

Rodip® ZNX

Clear passivate for zinc-nickel, zinc-iron and zinc-iron-cobalt surfaces. This single component process is completely free of Cr(VI), Co and complexing agents

  • Easy to control, long bath life
  • Easy to waste treat
  • Not dependent on the conversion of hexavalent to trivalent chromium
  • Excellent tolerance to the drag-in of iron, nickel, cobalt, zinc and tin
  • Has an inherent ability to form strong bonds with subsequent sealers, topcoats, lacquers and paints

900924

Blue

Unifix® Zn 3-15

High performance passivate which produces heat resistant uniform blue passivate films on zinc with high corrosion resistance

900924

Tridur® Zn B

High performance passivate which produces heat resistant blue to yellowish iridescent passivate films on zinc with high corrosion resistance

  • Suitable for rack and barrel plating

Unifix® Fe/Ni 3-12 L

Bluish iridescent passivate for zinc-nickel deposits with high corrosion resistance even after heat treatment

  • Suitable for rack and barrel plating

Unifix® Ni/Fe 3-10 L

Bluish to iridescent passivate for zinc nickel deposits with high corrosion resistance even after heat treatment

  • Recommended to use over Zinni AC AF 210 on brake calipers
  • Easy waste treatment

900924

Unifix® Zn 3-14 L

Blue passivate for zinc with good corrosion protection

  • Completely free of Cr(VI) and cobalt

900924

Unifix® Zn 3-13

Blue passivate for zinc with good corrosion protection

  • Completely free of Cr(VI) and cobalt

3641289

CorroTriBlue® Extreme

Deep blue passivate for zinc with good corrosion protection

  • Suitable for rack and barrel plating

900924

CorroTriBlue®

Clear blue passivate over alkaline and acid zinc with basic corrosion protection

  • Highly suited to rack and barrel applications
  • Easy to handle, control and wastewater treat

Unifix® Zn 3-17

Cobalt free thin-film blue passivate for zinc when basic corrosion protection is required. Suitable for all Zinc surfaces, specially recommended for acid Zinc

63172992

Black

Tridur® Zn H1

Black passivate for zinc deposits from cyanide free alkaline zinc electrolytes. Innovative pigments produce homogenous deep black finish even over large surfaces with Atotech's sealer or post dip applied

  • For rack and barrel application
  • Highly resistant against Fe-contamination

63172992

Unifix® Zn 3-28 L

Black passivate for zinc deposits from alkaline zinc electrolytes. It is completely free of Cr(VI) and silver

43517317

Unifix® Zn 3-29 L

Black passivate for zinc deposits from acid zinc and cyanide electrolytes. It is completely free of Cr(VI) and silver

1222871

Unifix® Fe 3-24 L

Black passivate for zinc-iron deposits

  • Produces a homogenous black passivate film
  • Highly suited for barrel application

1222871

Tridur® ZnFe H1

Black passivate for zinc-iron deposits; Innovative pigments produce homogenous deep black finish even with low Fe-content in the deposit

  • For rack and barrel application
  • Highly resistant against Fe-contamination

1222871

CorroTriBlack ZnFe

A black, two component, liquid passivate for zinc-iron deposits

  • Produces a homogenous black passivate film
  • Fe-content in the deposit must be maintained between 0.5 and 0.8% to achieve optimum passivate performance
  • Highly suited for rack plating
  • Free from complexing agents so is easy to wastewater treat
  • When used with Corrosil® Plus 501 (BG) achieves excellent
  • Corrosion resistance, even after heat treatment

1223017

Unifix® Ni 3-30 L

Homogenous black passivate especially developed for deposits with a zinc-nickel content of 12-15%. It provides a good corrosion protection in combination with the Atotech post-dip or sealer product range

  • Suited for rack and barrel application

1223017

Tridur® ZnNi H1

Tridur® ZnNi H1 produces an attractive, homogenous black to slightly iridescent passivate film onto electroplated deposits of zinc nickel with an alloy content of 12-15% nickel

  • The two component liquid passivate is completely free of hexavalent chromium
  • Highly suited for rack plating application
  • Provides a good corrosion protection in combination with the Atotech post-dip or sealer product range

1223017

CorroTriBlack ZnNi

A black, two component, liquid passivate based upon trivalent chromium for zinc-nickel deposits

  • Attractive, homogenous black passivate film
  • Alloy content of 12 - 15% nickel
  • Chemically stable with a long solution life
  • Highly suited for barrel plating application
  • Easy to use with two products for make-up and maintenance
  • Must only be used in combination with Corrosil® Plus 600 Black

900924

Yellow

Tridur® Zn Y3

Tridur® Zn Y3 produces yellowish iridescent passivate films onto electroplated zinc deposits from alkaline and acid electrolytes with very good corrosion protection for electrics / electronics industry

  • Completely free of Cr(VI) and toxic selenates
  • Easy to waste treat
  • UV resistant
  • Color can be intensified with Atotech's yellow dyes

Unifix® Zn 3-15 L Part B

Unifix® Zn3-15 L Part B is an additive to adjust yellow color of Unifix® Zn 3-15 L

  • Free of toxic selenates

Unifix® Yellow

Unifix® Yellow is a liquid yellow dye for Atotech's blue or iridescent and thick film passivates, which can be used either in passivate or rinse tank

  • UV resistant
  • No influence on the corrosion protection of the passivate

Rodip® Yellow Dye 702

Rodip® Yellow Dye 702 is a solid yellow dye for Atotech's blue or iridescent and thick film passivates, which can be used either in passivate or rinse tank

  • UV resistant
  • No influence on the corrosion protection of the passivate

Production Technologies 

Tricotect®

Regeneration system for Cr(VI)-free passivates for the continuous removal of Fe and Zn. Tricotect® allows a continuous online purification of the passivate bath, therefore no interruption of production is needed. The contaminative metals can be effectively removed without influencing the beneficial Cr(III)

  • Consistent high passivation quality (color and corrosion protection)
  • Combinable with diversity of passivate processes
  • One equipment usable for several plating lines (rack and barrel)
  • Cost effective due to elemination or reduction of dumps and remakes
  • Significant savings on valuable substances
  • Wastewater minimization