Nano Composite Coatings for electrical Contacts (nCo3)

Centrum Partners:

• Staffan Jacobson, Frida Riddar, Ulf Jansson and Karin Larsson (Uppsala)
• Hans Högberg and Lars Hultman (Linköping)

Scientific Objectives

• Assessment of the tribological behavior of M-A-X coatings in a number of tests simulating a wide range of electrical contact types.
• Mapping of the mechanical performance of M-A-X coatings, as function of thickness, substrate material, etc. Functionality rated compared with current solutions (silver, gold and TiN).
• Identification of at least one alternative promising nano composite coating for electrical contacts

Technology Transfer Objectives

• Initial mapping of tribological behavior and contact resistance performance of the most promising M-A-X system to act as a guide for the concurrent product development at Impact coatings and ABB. 
• An engineering guideline for the use of multifunctional coatings in different contact applications

Research plan:

Development of tribological coatings is based on knowledge of their performance and limitations in tribological contacts. Therefore dedicated evaluation is required in specially designed test equipment followed by high resolution microscopy and analyses to understand the mechanisms of coating limitations.

Initially, the work will concentrate on a solution based on M-A-X coatings developed by Impact coatings. The work will also include other quaternary, ternary, and binary materials from UU and LiU, where carbon or nitrogen is the common element and nano structures are needed to offer the unique combination of ceramic like wear resistance and friction behavior and metal like ductility and conductivity. For electrical contacts, the beneficial electrical properties must be combined with chemical inertness, low friction, high wear resistance and high ductility.

The project will involve mechanical and tribological mapping, high resolution mechanism studies, surface analysis and wide-ranging studies of model contacts exposed to combined load of electrical current, vibrations, sliding contact and corrosion.

One of the final goals is to achieve the full understanding needed to write an engineering guideline for the use of these coatings in different contact applications. The designers and users of contacts need to now how to select the proper substrate finish, coating material, thickness, interlayer, and counter material. Data on contact resistance as a function of load, sliding conditions, etc is also needed.