Nitrogen and boron ion implantation into electrodeposited hard chrome

• Published in: Surface & coatings technology Vol. 97; no. 1; pp. 250 - 253
• Main Authors: Walter, K.C., Kern, K.T., Tesmer, J.R., Scarborough, W.K., Woodring, J.S., Nastasi, M.
• Format: Journal Article Conference Proceeding
• Language: English
• Published: Lausanne Elsevier B.V 01-12-1997; Elsevier
• Subjects: Applied sciences; Electrodeposited hard chrome; Exact sciences and technology; Ion implantation; Metals. Metallurgy; Nanohardness; Other surface treatments; Production techniques; Surface treatment; Nanohardness; Ion implantation; Electrodeposited hard chrome; Elastic modulus; Nitrogen ion; Mechanical properties; Implantation; Experimental study; Microhardness; Surface treatment; Ion irradiation; Friction coefficient; Boron ion; Electrodeposition; Hard coating
• ISSN: 0257-8972; 1879-3347
• DOI: 10.1016/S0257-8972(97)00194-1

Electrodeposited hard chrome has been ion implanted with nitrogen alone, boron alone, and a combination of nitrogen and boron. Separately, nitrogen and boron implantation was carried out at 75
keV and incident doses of 2, 4 and 8×10
17
at
cm
−2. Samples implanted with both nitrogen and boron used beam energies of 75
keV and incident dose levels of 4×10
17
N-at
cm
−2 and 4×10
17
B-at
cm
−2. All ion implantations were accomplished using a beam-line system. The retained dose was measured using ion beam analysis. Surface hardness, wear coefficient and the coefficient of friction were determined by nanohardness indentation and pin-on-disk wear testing of each sample. Ion beam analysis indicated a majority of the incident dose was retained. At a depth of 50
nm, the surface hardness increased from 18±1
GPa for unimplanted chrome, to a maximum of 23±4
GPa for boron implanted chrome and 26±1
GPa for nitrogen implanted chrome. Pin-on-disk wear testing indicated reductions in the wear coefficient by factors of 1.3–7.4, depending on the implantation treatment. It is shown that nitrogen implantation of chromium results in lower wear coefficients than boron implantation.