For more than forty years, academic and industrial researchers from all over the world have taken a strong interest in alternative processes for hard chromium plating using hexavalent ions. The benefits of substitute processes are obvious, as the toxic and carcinogenic aspects of hexavalent chromium are well known.
Immersion tin and lead-free hot air solder leveling (HASL) coatings based on SnCu or SnAgCu alloys are widely used as surface finish materials for printed circuit boards (PCB). These coatings prevent the underlying copper from corrosion and preserve its solderability during lead-free assembly processes and for a long storage life of PCBs.
#pollutioncontrol #research #electronics
The Leading Edge Guide to Top Quality Anodizing using the Complete Spectrum Approach with a Universal Type I – II – III – (123) Mixed Electrolyte
This paper discusses recent research work on the development of a functional trivalent chromium plating process from a trivalent-based electrolyte to replace hexavalent chromium plating. Hexavalent chromium plating has been used for many years to provide hard, durable coatings with excellent wear and corrosion resistance properties. However, hexavalent chromium baths have come under increasing scrutiny due to the toxic nature of the bath, effects on the environment and workers’ health. In this paper are results from our development program aimed at achieving properties comparable to existing hexavalent chromium plating for functional applications. Specifically, recent efforts in plating chromium on the internal surfaces of cylindrical parts will be presented, as well as wear test data.
#medical #SURFIN #research
Solvent substitution for maintenance and overhaul operations of military systems has been a primary environmental concern for many years. Cadmium replacement in these systems has been targeted for decades. Both of these areas have a common obstacle for implementation of any potential alternate. Hydrogen embrittlement of high strength steel is the most predominant unforeseen hurdle since high strength materials show sensitivity to the phenomena and the source of the hydrogen can be anything within the fabrication process, maintenance practice or the natural corrosion cycle. Standardized testing on this issue has traditionally stemmed from the aerospace industry where it is a principal focus.
#aerospace #military #sustainability
This article contains a collection of the advertisements published in the July, 1930 issue of Metal Cleaning and Finishing. They capture an instant in time, when the surface finishing industry was quite different from what we find today.