Corrosion and wear mechanisms of aluminum alloys surface reinforced by multicharged N-implantation (original) (raw)
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Advances in Materials, 2019
The weakness of aluminium and its alloys are relative low hardness and wear resistance. To improve this weakness a nitrogen ion implantation technique has been carried out. For the purpose, an ion implantation process was carried out for various of dose such as 0.578×10 16 ion/cm 2 , 0.706×10 16 ion/cm 2 , 0.842×10 16 ion/cm 2 , 0.970×10 16 ion/cm 2 , and 1.106×10 16 ion/cm 2 at a certain energy and beam current, 60 keV and 75 µA, respectively. Hardness test was performed using microhardness tester, the corrosion resistance was tested using the electrochemical method, and the crystal structure was analyzed using X-ray diffraction. From the hardness test result, it can be concluded that the optimum hardness in order of 37.5 VHN was achieved at an ion dose of 0.83×10 17 ion/cm 2. While the hardness for the untreated sample was 18.70 VHN. It meant, there is an increasing hardness by a factor of 100,53%. At these conditions, the corrosion rate reduces from 0.012 mmpy to 0.011 mmpy or reduce by a factor of 8.3%. Based on the XRD analysis, it can be obtained the AlN phase is formed through the peaks at 2-theta was 39.37° (111), 45.76° (200), and 66.88° (202).
Surface and Coatings Technology, 2012
This paper deals with the surface strengthening of aluminum alloys by means of a new process allowing multicharged nitrogen ion implantation. X-ray photoelectron spectroscopy, grazing-incidence X-ray diffraction and atomic force microscopy were used to study microstructural changes involved by implantation. This microstructural study revealed the formation of AlN and AlONγ due to the low nitrogen concentration gradient obtained with multi-charged implantation. Nanoindentation and wear tests were performed to evaluate the mechanical properties of implanted surfaces. A significant improvement of wear resistance was observed as a consequence of the nitride protective layer formation. The observed surface hardening is attributed to both AlONγ and AlN formations and to the precipitation-induced stress.
Journal of Physics: Conference Series
The present work reports the effect of nitrogen ion implantation on aluminum alloy 7075. The microhardness, corrosion resistance, and surface nanostructure were investigated. The implantation was carried out at energy 60 keV with the ion doses used were 1.70 × 10 17 ion/cm 2 , 1.86 × 10 17 ion/cm 2 , 2.02 × 10 17 ion/cm 2 , 2.17 × 10 17 ion/cm 2 , and 2.33 × 10 17 ion/cm 2. The microhardness test was performed to study the hardness of the implanted layer which was characterized by X-ray Diffraction (XRD). The potentiodynamic corrosion test was performed in a 0.5 mol/l NaCl solution. The surface nanostructure was investigated by atomic force microscopy (AFM) to study the surface roughness after implantation. The results showed that the microhardness after implantation at 2.17 × 10 17 ion/cm 2 increased by 90.81%. The increase was attributed to the formation of the AlN phase. The AlN phase was confirmed at 2-theta peaks of 39.53°, 45.84°, 66.90°, and 80.54°. The corrosion test showed the improvement of corrosion resistance by the decrease of corrosion rate from 4.49 mpy to 1.43 mpy. The atomic force microscopy showed the arithmetical mean height (Sa) value was 37.5 nm and the root means square (Sq) value was 47.6 nm. The ion implantation induced the change of material surface due to the penetration of nitrogen ion into the material.
Electrochemical study of multiple-energy nitrogen-ion-implanted aluminium alloys
Materials Science and Engineering: A, 1989
the pH range between 4 and 9 [1 ]. This behaviour Nitrogen-implanted aluminium is reported to is better than that deducible from the electroshow a better pitting corrosion resistance. Howchemical series and is due to the formation of an ever, the corrosion behaviour depends on the insoluble and protective layer of aluminium number of nitrogen atoms available on the surface hydroxide. However, the aluminium corrosion and the thickness of the implanted layer. In singlerate increases noticeably when the pH value energy implantations the number of nitrogen changes from the near neutral conditions. In fact, atoms available on the surface is less than that in in these cases the aluminium hydroxide does not the bulk because of the Gaussian nature of the become a more protective layer. depth profile obtained. To overcome this difficulty,
Surface and Interface Analysis, 2008
This work is focused on a detailed analysis of passive layer formed on AA2024-T3 aluminum alloy, in unmodified and nitrogenimplanted conditions. This study is the first step in analyzing the possible beneficial effect of nitrogen implantation in the simultaneous improvement of the tribological properties and pitting resistance. The implanted surface has been characterized by XPS and atomic force microscopy (AFM), and SEM/EDX has been used for microstructural characterization. XPS depth profile of the implanted surface shows the formation of AlN through the implanted layer. AFM studies have confirmed the increase of the surface roughness of AA2024-T3 due to N + implantation. Another interesting result of the present work is the detection by EDX analysis, of implanted alloy of a specific concentration of the implanted nitrogen in Al-Cu-Fe-Mn-Si particles with regards to the other microstructural constituents.
Effects of high dose nitrogen implantation into aluminum
Vacuum, 2003
The effects of high dose nitrogen implantation into aluminum on phase structure and mechanical properties were studied by using Rutherford backscattering (RBS), scanning electron microscopy (SEM), atomic force microscopy (AFM), nanoindentation and friction/wear tests. The samples were implanted using both, separated or unseparated nitrogen beams, at the temperatures ranging from 201C up to 5501C, the highest fluencies used were equal to 1 Â 10 19 at N/cm 2 . The effects obtained indicate the formation of an AlN layer. At higher implantation fluencies the microtopography of the sample surface becomes granular. The latter effect is likely to be due to the incompatibility between Al and AlN crystalline structures. The samples implanted up to a fluence of 1 Â 10 18 at N/cm 2 at RT revealed best mechanical properties; increased hardness and low friction coefficient.
Tem Investigation and Hardness Improvement of A N+ Implanted Al-Alloy
MRS Proceedings, 1995
The surface modification induced by nitrogen ion implantation on the Al-alloy 7075 has been studied with the aim of understanding the microstructural evolution and the phase separation during the implantation process. 150 keV N2+ ions have been implanted at different temperatures from 373 K to 473 K, with a current density of 5–15 µA/cm2 on previously polished samples. The implanted dose was in the range 1 × 1017 N/cm2 - 5 × 1017 N/cm2. Vickers micro-hardness tests and friction coefficient measurements show a real improvement in the mechanical behaviour of the alloy after the treatment.TEM observations of specimens treated at low temperature with different ion dose have been carried out at 200 kV on cross-sectional samples, prepared by ion beam milling. First results show the presence of small AlN hexagonal precipitates whose evolution is followed as a function of the implanted dose.
Nanohardness and transmission electron microscopy study of nitrogen-implanted aluminium
Surface and Coatings Technology
Nitrogen implantation into aluminium with the intent of forming AIN has been studied for many years. Its hardness suggests that the production of such a superficial layer in aluminium alloys may alter their mechanical properties in such a way that they could be used in new applications. Among the possible applications, one can cite wear in a plastic bottle injection moulding machine; mould prototypes are made in Al alloy, while moulds in production are made of steel because of their greater wear resistance. This paper is devoted to the study of the surface hardness of pure Al implanted with molecular nitrogen of 100 keV for wide ranges of doses and temperatures. Hardness OS. depth has been measured with a nanoindenter, and the results are supported by transmission electron microscopy measurements of the implanted layer. This latter technique reveals that nitrogen implantation leads to the formation of AIN precipitates which have a crystallographic relationship with the host aluminium matrix. Furthermore their size depends strongly on the implantation conditions. The hardness results are interpreted in terms of precipitate concentration and size.
Wear resistance of TiN coatings implanted with Al and N ions
Vacuum, 2007
Titanium nitride (TiN) coatings were prepared on HS 6-5-2 high-speed steel cutting inserts and next implanted either with Al ions (fluence 2 Â 10 17 ions/cm 2) or with Al and N ions (fluence (1+1) Â 10 17 ions/cm 2) on the rake face. Microhardness and friction coefficient of the implanted surfaces were examined. A noticeable increase of microhardness in Al implanted inserts has been observed. The elemental composition and structural properties of the surface layer were examined by glow discharge optical emission spectroscopy (GDOES) and gliding angle X-ray diffraction (XRD). The tests of turning of 40 H constructional steel with the cutting inserts have shown an improvement in the implanted inserts, especially marked in those implanted with Al+N.
Study of Microstructural and Corrosion Properties of Aluminium Alloy 7075 after Plasma Nitriding
Jurnal Sains Materi Indonesia
Plasma nitriding is a treatment process of metals by depositing nitrogen into metal that considered to be nitrided by mean of increasing the mechanical, physical, and chemical properties of the metal. This treatment will form a hard layer compund of Al-N on the surface of the sample. In this study, aluminium alloy 7075 was nitrided which the application of it to structural part of aircraft makes it vulnarable to not only corrosion and wear attack but also decreasing the hardness of the material. One method to overcome these issues is plasma nitriding. The purpose of of this research is to do the characterizations of plasma nitrided aluminium alloy 7075 regarding its microstructure, mechanical, and chemical properties. The characterizations that had been done were microhardness Vickers testing, SEM-EDX, and electrochemical corrosion testing Potensiostat. The hardness of the sample increased 55% from 75,88 VHN (raw material) to 117,68 VHN (at optimum parameter). The depth of the white...