Archive for July, 2015

XRF Testing Options for Zinc Nickel Measurements

The use of zinc-nickel coatings is not new to metal finishing but it has seen an increased interest in recent years because of the benefits it offers over zinc and other zinc alloy coatings.  The major benefits of zinc-nickel include its high resistance to corrosion, wear, and abrasion – even at extreme temperatures. These characteristics result in a longer product life and, because of that, zinc-nickel has become the preferred plating in automotive and aerospace applications with specifications ASTM B841 and AMS 2417 being written for its use.

However, adding the typical 7% or 15% of nickel will drive the cost of the plating up anywhere from 1.5 to 2.5 times the cost of basic zinc plating.  Increased costs only heighten the need for accurate process control – having a quality control system in place to verify that plating meets specifications and avoiding costly over plating.  X-ray fluorescence (XRF) technology is the most popular approach to obtaining accurate and repeatable measurements of zinc nickel plating thickness.

Eastern Applied Research can provide three XRF related options when metal finishers add ZiNi capabilities or convert from other processes to this alloy plating.  Those options include:

Hitachi High-Tech XRFDesktop XRF: newer model XRF analyzers will have the ability to measure Zinc-Nickel thickness and the alloy composition.  Eastern Applied offers the Hitachi XRF line of equipment, which features the FT-110A system for basic coating thickness applications and composition.

Handheld XRF: The XMet8000 from Oxford Instruments is the only handheld system that we have seen provide accurate and repeatable coating thickness measurements.  It can be calibrated for this specific interest (assuming the Ni present remains consistent) and can be beneficial when large components need to be measured.

Adding Capabilities to an Existing XRF: Unfortunately, some older models of x-ray fluorescence (Twin Cities International, Veeco, some Fischer Instruments, etc) will not have the flexibility to add this application.  However, it is often possible to add it to newer XRF analyzers by simply adding a set of certified reference standards.  The Eastern Applied Research technical staff can confirm if this is possible with an existing system and our in-house XRF standards laboratory can supply these standards.

Has your organization added Zinc Nickel (ZiNi) coating applications?  Are you considering it?
Contact Eastern Applied to discuss the options that can be made available so that you can control your processes.