Reduction of friction and wear by ion-implanted carbonized photoresist

Abstract

The influence of ion-implanted carbonized photoresist layers (AZ 5210) on wear and friction is discussed in this paper. Photoresist, an organic resin, was used because of the simplicity of coating the sample, accurate control of the layer thickness, and high amount of carbon. The samples investigated were coated by conventional spin-on techniques with layer thicknesses varying from 0.2 μm to 2.2 μm. Subsequent ion bombardment at energies of 200 keV and 1.4 MeV with doses ranging from 1 × 10 16 cm -2 to 1 × 10 17 cm -2 caused carburization, densification, and a mixing of the layer with the steel substrate. Transmission electron microscopy investigations, Raman spectroscopy, elastic recoil detection analysis, and microhardness measurements confirmed the production of a hard, amorphous, hydrogen-containing (about 17%) carbon layer after implantation. The layers were deposited onto different steels (AISI 52100, AISI 440B unhardened, and AISI M2) and after implantation of boron, aluminium, phosphorus, arsenic and titanium, showed a strongly reduced friction coefficient (lower than 0.2) and drastically reduced wear behaviour. The duration of the wear reduction depended on both the thickness of the carbonized photoresist layer and on the implanted ion dose. Doses of 5 × 10 16 cm -2 for hard steels and doses of 1 × 10 17 cm -2 for soft steels are necessary to produce a sufficient layer adhesion by ion beam mixing.