Accession Number:

ADA551725

Title:

Ultra-High Efficiency / Low Hydrogen Embrittlement Nanostructured Zn-Based Electrodeposits as Environmentally Benign Cd-Replacement Coatings for High Strength Steel Fasteners

Descriptive Note:

Final rept. 4 Aug 2008-30 Apr 2011

Corporate Author:

INTEGRAN TECHNOLOGIES INC TORONTO (ONTARIO)

Personal Author(s):

Report Date:

2011-04-01

Pagination or Media Count:

54.0

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, torquetension 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 Integrans 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.

Subject Categories:

  • Inorganic Chemistry
  • Properties of Metals and Alloys

Distribution Statement:

APPROVED FOR PUBLIC RELEASE