Showing papers in "Plating and Surface Finishing in 2006"

The story of nickel plating - Part II

Abstract: Among the major metals electroplated in commerce is nickel. From decorative bright finishes to today's nanotechnology and MEMS applications, nickel is there. With all of the advanced technology involving nickel plating in our industry, it is somewhat surprising to learn that nickel plating has been going on for nearly 150 years. When the AESF (then the AES) celebrated the 50 th anniversary of its founding in 1959, the June issue of Plating that year featured a series of articles relating the development of the important plated metals of the mid-20 th century. The following article, written by Dr. George Dubpernell, one of the industry pioneers, relates the story of nickel plating, from its very inception to the 1950s. Last month, Part I dealt with the very early developments to the point where the essentials of today's nickel baths were being understood. This last of two parts begins with the emergence of the Watts bath and ends in the heyday of bright nickel-chromium plating. The reader will find the personal details to be as interesting as the technical ones.

Alternatives to hexavalent chromium to comply with European Union's Directives (ELV, RoHS and WEEE)

Abstract: The deadline for the European Union's Directives is approaching. RoHS (Restriction of Hazardous Substance) is effective July 1, 2006, WEEE (Waste Electrical and Electronic Equipment) is effective December 31, 2006 and the ELV (End of Life Vehicle) directive is effective July 1, 2007 for hexavalent chromium. Industry is working hard to find a suitable alternative for compliance. Ideally a drop-in replacement, at a reasonable cost that meets engineering specification would be preferred. This paper describes various options that are commercially available to comply with these directives.

Mapping and modeling tools and techniques for metal finishing process improvement

Abstract: Process mapping and modeling tools provide for improved process visualization and understanding that facilitates identification of opportunities for process improvement. Systematic techniques and tools for process improvement also facilitate decision-making and expedite process improvement implementation resulting in lean manufacturing improvement, improved quality and performance and reduced life cycle costs. These tools and techniques can be used over a project life cycle to pursue continuous process improvement.

Do's & don't's?

Abstract: What is hydrogen embrittlement? How does it form? What is the mechanism, i.e., how does it take place? Why does hydrogen cause embrittlement? I really do not know the answer to the preceding four questions. There are numerous scientifi c papers dealing with these questions. I have read many of them over time and I still don’t know. An excellent paper was given by Dr. Chris Raub when he received the AESF Scientifi c Achievement Award at AESF SUR/FIN 1993, entitled “Hydrogen in Electrodeposits: Of Decisive Importance, But Much Neglected.” What I do know is that hydrogen embrittlement can cause catastrophic failure of high strength steel and other alloys. The failure is usually in the form of cracking or complete separation. It can also cause blisters in both the basis metal and at the plating interface, reduced ductility, internal voids and lower yield strength. What steels are subject to hydrogen embrittlement? I have found controversy about this. In general, high-strength steels, including “low alloy steels” and some stainless steels are vulnerable. Often steels susceptible to embrittlement are related to their tensile strengths. Dini indicates that steels with tensile strength values of 1240 to 2140 MPa (180,000 to 310,000 lb./in) are susceptible to embrittlement. Other references indicate risk above 1100 MPa (160,000 lb./in). In general, the higher the tensile strength of the steel, the more susceptible it is to hydrogen inclusion and embrittlement. Even austenitic alloys are susceptible. Maraging high-strength steels with tensile strengths of 2740 MPa (397,000 lb./in) have higher susceptibility to hydrogen embrittlement. Hydrogen Embrittlement from Plating Processes

Zinc in the world of electroplating

Abstract: Zinc is among the "workhorse" metals plated today. In the automotive industry alone, zinc is the mainstay in providing corrosion resistance to everything from automotive body panels to fasteners, brackets and other small parts. It is plated on everything from steel coils to small screws. The use of zinc as a sacrificial corrosion agent dates back to the first half of the 19 th century. When the AESF (then the AES) celebrated the 50 th anniversary of its founding in 1959, the June issue of Plating that year featured a series of articles relating the development of the important plated metals of the mid-20 th century. The following article, written for the AES Golden Jubilee by Ernest W. Horvick, who spent most of his career at the American Zinc Institute, relates the history of zinc plating in all of its incarnations, including barrel, rack and continuous strip plating.