| Nitrogen ions were implanted into LY12CZ aluminum alloy by plasma immersion ion implantation (PIII) technique. The chemical states, composition distributions, tribological properties, and anti-corrosion behaviors of the N-PIII coupons in 3.5% NaCl saturated solution were investigated. X-ray photoelectron spectroscopy (XPS) analysis indicates that the modified layer is mainly composed of AlN phase and a fraction of Al2O3 compounds. The depth profile of implanted nitrogen ion has two peaks, corresponding to 40nm and 88nm from the surface, respectively. The surface hardness is obviously improved by dispersion strengthening from AlN phase, and the maximum value increases by 140%. Friction and wear behaviors of all these samples exhibits that the friction coefficient reduces from 0.47 to 0.38. Compared with the untreated substrate, the anode polarization curves reveal that the corrosion potential (Ecorr) of all implanted samples increase and corrosion current density (Icorr) decrease, the maximum Ecorr increases by 200mV and the minimum Icorr decreases by over two orders of magnitude. It also indicates that the wear tracks of modified coupons are much shallower and narrower than that of untreated sample, the minimum wear loss decreases by 43.4%. Tribological property and corrosion resistance of aluminum alloys strongly depended on the composition depth profiles of the modified layers. |
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