FORD WSS-M3P38-A Performance - Zinc Phosphate and Zirconium Oxide for Aluminum Intensive Production

The standard “FORD WSS-M3P38-A Performance – Zinc phosphate and zirconium oxide for aluminum intensive manufacturing” developed by Ford Motor Company (FORD) specifies performance requirements for conversion coatings produced on assemblies made of steel and aluminum materials. The zinc phosphate coating is formed on iron-based substrates and the zirconium oxide coating is formed on aluminum substrates. The assemblies are then painted.

This standard was originally designed for conversion coatings produced in a process for aluminum-intensive assemblies. In this process, iron, steel, and zinc or zinc alloy-coated steel are coated with a zinc phosphate coating, and aluminum substrates are coated in a subsequent step with a system based on zirconium oxide technologies. This process is designed for use in aluminum-intensive automotive applications where the aluminum content in production is approximately 30 percent to 70 percent of the total substrate mix.

In this standard, the requirements are defined as follows:

• The supplier must contact Ford materials engineering before initiating qualification testing.
• Materials technical data sheets, design matrix and all other material related processing information should be submitted for review at the same time.
• Before material is introduced into a production facility, a process diagram and facility-specific process must be developed.
• All materials approved under this specification must meet all engineering requirements when applied under assembly plant conditions.
• In some cases, a partial qualification submission is permitted. In this case, the qualification requirements depend on the extent of changes made to the material. Testing requirements should be agreed upon between Ford materials engineering and the supplier prior to testing.
• Material suppliers and parts manufacturers must comply with the company's standard requirements for production materials (WSS-M99P1111-A standard).
• Ford Motor Company may, at its option, perform analysis of materials and representative parts or panels supplied in accordance with this standard. Primary analyses include, but are not limited to, material chemical analysis, coating analysis, and corrosion and mechanical resistance testing.
• All base material component ranges and base material production control limits must exceed the standard measurement repeatability and reproducibility requirements.
• The supplier must notify the appropriate Ford material engineering if any incompatibility with other process-related materials (e.g. sealants, adhesives, electroplating, etc.) is anticipated.
• The supplier must be aware of changes in the technology of materials related to the process that may affect the compatibility and performance of pretreatment products. Consequently, appropriate material compatibility testing is performed to ensure that the process will provide the required performance.
• The physical properties (zinc phosphate coating weight, zinc phosphate crystal size and zirconium coating weight) must meet the requirements specified in the standard.
• Testing is conducted on standard test panels representative of current production substrates and current mill oils and lubricants. Test panels shall be prepared in accordance with external performance specification WSS-M2P180.
• The supplier should perform a test design (response surface analysis is recommended) to determine the process window for pretreatment controls. For zirconium oxide pretreatment, a minimum of four variable test designs is recommended, including zirconium concentration, pH, process time, and process temperature. Additional operating variables may include fluoride control (in zinc phosphate and zirconium oxide pretreatment baths), other pretreatment bath key components/parameters, and substrate cleaning conditions (fresh or old alkaline cleaner bath).
• In terms of resistance properties, the requirements given in the standard must be complied with on the basis of: paint adhesion, water resistance, humidity resistance, corrosion resistance, chip resistance, cylindrical mandrel testing and glass bonding/paint system compatibility.

Our organization, which has been trying to support businesses from every sector with its testing, measurement, analysis and evaluation studies carried out in a wide range for years, has a strong staff that closely follows the developments in the world in the field of science and technology and constantly improves itself. In this context, testing services in accordance with the "FORD WSS-M3P38-A Performance - Zinc phosphate and zirconium oxide, aluminum intensive production" standard are also provided to businesses.