Ultra-High Efficiency / Low Hydrogen Embrittlement Nanostructured Zn-Based Electrodeposits as Environmentally Benign Cd-Replacement Coatings for High Strength Steel Fasteners
Abstract
The objective of SERDP project WP-1616 was to develop, and investigate the benefit of, nanostructured Zn-based alloys over current (Cd) and emerging (LHE ZnNi) sacrificial protective coatings, focusing in particular on the relevant properties for high strength steel fasteners. In Phase I, a number of nanostructured zinc (Zn)-based alloy coatings were successfully synthesized (Zn-Co, Zn-Fe, Zn-Ni and Zn-Ni-Co, in particular) based on simple modifications to currently available (off-the-shelf) commercial bath chemistries. The various nanostructured Zn-alloys were then subjected to comprehensive characterization and performance tests, including: grain size, crystallographic texture, microhardness, ductility, torque/tension friction, salt-spray corrosion and hydrogen embrittlement performance. Based on the Phase I results, the alkaline Zn-Ni, acid Zn-Ni and acid Zn-Ni-Co plating systems where selected as the most promising alloys to carry forward for further optimization in Phase II. The results in this report show that Integran's waveform engineering approach provides additional benefit over conventional DC plating and can be successfully integrated into a commercial scale as a potential swap-out technology with current Cadmium-plating.
Document Details
- Document Type
- Technical Report
- Publication Date
- Apr 01, 2011
- Accession Number
- ADA551725
Entities
People
- Brandon Bouwhuis
- Jonathan Mccrea