Structural and nanohardness behavior of low energy, high flux nitrogen implanted austenitic stainless steel için kapak resmi
Structural and nanohardness behavior of low energy, high flux nitrogen implanted austenitic stainless steel
Başlık:
Structural and nanohardness behavior of low energy, high flux nitrogen implanted austenitic stainless steel
Yazar:
Dal, Refika, author.
Yazar Ek Girişi:
Fiziksel Tanımlama:
xii, 49 leaves: illustrarions, charts;+ 1 computer laser optical disc.
Özet:
316 austenitic stainless steels (SSs) are one of the most commercial and technological alloys and extensively used in the field of defence, nuclear and biomedical applications due to its excellent corrosion resistance in abrasive and erosive environment. However, this type of steel is rather soft, and these results in poor durability, in particular when this material (316 SS) is in contact with other surfaces. In addition, 316 SS is nonmagnetic at room temperature. In order to make the surface of 316 SS harder, nitrogen ion beam implantation and wear resistant method is applied. Earlier studies of high dose nitrogen ion implantation into the surface of austenitic SSs around 400 °C substrate temperature showed that an expanded austenite phase (The Nitrogen phase in the FCC lattice of 316 SS) gives excellent wear resistance with high hardness value. In this study, type 316 stainless steel (SS) was implanted with low energy (700 eV), high flux (2.9 mA/cm2) nitrogen ions at 400 °C substrate temperature in order to harden its surface. Microhardness and nanohardness measurements were carried out on the nitrogen implanted surface and on the nitrogen implanted cross-section under the applied loads ranging from 6 mN to 30 mN. Both microhardness and nanohardness data suggest that the hardness of the N implanted 316 SS significantly increases compared to the hardness of the substrate material (by a factor of 3 to 4).The hardness increase is believed to be due to the high amount of nitrogen, the thick nitrogen implanted layer and macroscopic residual compressive stresses, the formation of which is verified by θ/2θ XRD scans as lattice expansions about 10 at. %. SIMS profiles suggest concentration-dependent diffusion behavior for the N implanted layers. Based on SIMS and SEM/EDX data, nitrogen implanted layers are 4-5 micron thick and constituting about 28 %.
Konu Başlığı:
Yazar Ek Girişi:
Tek Biçim Eser Adı:
Thesis (Master)--İzmir Institute of Technology: Materials Science and Engineering.

İzmir Institute of Technology: Materials Science and Engineering--Thesis (Master).
Elektronik Erişim:
Access to Electronic Versiyon.
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