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The purpose of the paper is to study effect of the implantation of oxygen and helium ions on the corrosion performance of the AISI3l6L stainless steel. It presents useful new results which allows one to draw conclusions as to the suitability of the helium and oxygen ion implanted AISI 316L stainless steel for biomedical use in the body.

The implantation of oxygen and helium ions was done on AISI 316L SS at an energy level of 100 keV at a dose of 1×10¹⁷ ions/cm², at room temperature. In order to simulate the natural tissue environment, an electrochemical test using cyclic polarization was done in a 0.9 percent sodium chloride solution at a pH value of 6.3 at 37°C. This was carried out on both the virgin and implanted AISI 316L stainless steel for the purpose of comparing performance. In addition to this, the hardness of the virgin and implanted samples was also studied using Vickers microhardness tester with varying loads. Besides, the surface morphologies of the implanted samples and the corroded samples were studied with XRD and SEM.

From the study the following findings are made. First, the XRD and SEM results were found to be in accordance with the corrosion test results. Second, the general corrosion behavior showed a significant improvement in the case of both helium implanted (icorr=0.0689 mA/cm²) and oxygen implanted (icorr=1.104 mA/cm²), when compared to the virgin AISI 316L SS (icorr=1.2187 mA/cm²). The pitting corrosion showed a significant improvement for helium implanted (Epit=230 mV) when compared to virgin material (Epit=92 mV). The oxygen implanted has not shown any improvement (Epit=92 mV). The surface hardness is found to be 1202 HV for helium implanted and 1020 HV for oxygen implanted, while it is found to be 195 HV for the virgin material. The hardness of the helium and oxygen implanted samples is found to be increased by about 600 percent and 500 percent, respectively, when compared to the virgin samples. Helium implanted samples show better performance in terms of corrosion resistance and hardness when compared to those of the oxygen implanted samples.

Although a number of authors have conducted many research on AISI 316L stainless steel, this work has original experimental results in terms of the oxygen and helium ion implantation parameters used and the specific tests: microhardness, electrochemical corrosion test, SEM and XRD that were used. It thus presents useful new results which allows one to draw conclusions as to the suitability of the Helium and Oxygen ion implanted AISI 316L stainless steel for biomedical use.

Corrosion resistance measurements were performed on AISI 316L stainless steel biomaterial samples after three types of treatments: abrasive finishing (MP), standard electropolishing (EP), and magnetoelectropolishing (MEP). The corrosion studies were carried out in Ringer's solution at a room temperature. Potentiodynamic plots obtained were the basis for the analysis of measurement accuracy and uncertainty with the statistical tests results done in Statistica 64/10 software. The results of corrosion studies indicate a significant difference in the breaking potential (Epit) values, dependent on surface treatment. The highest mean values have been obtained on samples after MEP (Epit=961 mV), much lower – after a standard electropolishing EP (Epit=525 mV), and the lowest – after the abrasive treatment MP (Epit=222 mV), all of them measured against a saturated calomel electrode SCE potential. The corrosion results obtained are well correlated with the nanoindentation measurement results (Young's modulus and nanohardness). The paper aims to discuss these issues.

The AISI 316L austenitic stainless steel samples served for the study. There were 11 (MP) and 14 (EP) samples used for each of the treatment, and 31 samples used for magnetoelectropolishing MEP. All polarization measurements were made after one hour immersion in the Ringer's solution. Statistical tests were used to treat the results obtained.

After magnetoelectropolishing MEP130, the pitting corrosion resistance is much better than that after abrasive polishing MP and/or a standard electropolishing EP130. It was proved on a big statistical sample that the pitting corrosion potential Epit after MEP130 is over 1.8 times higher than that after EP130 and over 4.3 times higher than that after MP. The results obtained are in good agreement with the nanoindentation measurement results.

This is an original study of the corrosion resistance of AISI 316L SS in Ringer's solution. The breaking potential Eb obtained is comparable with that of NiTi alloys, not reported anywhere before. The results have been well confirmed statistically (on 31 samples after MEP).

The purpose of this study is to describe the environmentally assisted cracking (EAC) of AISI 316L stainless steel as bare and coated cases in several corrosion environments. The main purpose of this study is to extend the lifespan of 316L material under corrosive fatigue in sodium chloride environments.

Fatigue tests carried out by using a Schenk type plane bending fatigue machine made by Tokyokoki Co. A scanning electron microscope (SEM) was used to observe the fracture surfaces and tested specimen surfaces. The micro-Vickers hardness of specimens was measured by using a PC-controlled Buehler–Omnimet tester.

Under reciprocating bending condition (R = −1) the behavior of 316L SS bare samples and 316L SS coated with Al-5%Mg samples were investigated comparatively at room temperature in ambient air and in several corrosion solutions. The results obtained from the data showed that Al-5Mg coating procedure significantly stabilized the 316L SS even in the most aggressive environment 5 per cent NaCl solution as compared with bare samples.

Al-5Mg coating showed a stable structure under the corrosion liquids used in the experiments. The coating material served as a stable barrier between the base material and the corrosion fluid, thus ensuring a tightness even in long-term tests below the endurance limit.

Stainless steels are very unique in that they offer a wide range and combination of resistance to corrosion, resistance to oxidation at high temperature and good mechanical properties at room temperature. With rapid industrialization all over the world, these very properties have led to extensive use of stainless steels in different industries. Austenitic stainless steels containing molybdenum exhibit corrosion resistance in both sulphuric acid and nitric acid. Stainless steel undergoes severe attack in sulphuric acid having concentrations in the range of 20‐85 per cent, whereas they are immune to nitric acid in any concentration. However, sensitized stainless steels are prone to intergranular attack in acids, even in nitric acid. Further, the attack is aggravated in the presence of aggressive ions. Study of the behaviour of stainless steels in a mixture of acids (nitric and sulphuric acid) is lacking in the literature. This paper, therefore, discusses the performance of AISI‐316 and 316‐L in sulphuric acid and nitric acid and a mixture thereof at room temperature. It is observed that the steels are quite resistant to sulphuric acid and nitric acid, but in the acid mixture they are not so resistant, especially in AISI‐316 SS in respect of corrosion resistance, even in acid mixture containing C1^‐ and Cu⁺⁺ ions.

The purpose of this paper is to present a methodology to predict initial crack growth behavior of crack or notch like stress raisers in AISI 316L(N) stainless steel material subjected to monotonic loading condition.

The methodology for critical crack blunting corresponding to crack initiation in crack or notch like stress raisers is based on critical plastic strain (Epc) at a characteristic distance (lc), where uniform strain (Eu) is considered as Epc and two grain diameter is considered as lc. Further crack growth is based on parabolic crack tip opening displacement (CTOD) scheme established based on coupled experimental and FEM analysis of compact tension (CT) specimen subjected to mode-I loading condition. The FEM predicted load-displacement plots is compared with experimental result of CT specimens with different a/W ratios. It has shown that the proposed methodology could account initial crack blunting appropriately and predict the fracture load and load-displacement plots for initial crack growth regime.

The results show that for crack growth with near straight crack front, experimental data from a CT specimen of particular a/W ratio coupled with plane strain 2D FEM analysis could predict load vs displacement plots for different a/W ratios when initial crack blunting is accounted appropriately with a local damage model.

The present study is a part of developing methods to analyse fracture behavior of AISI 316L(N) SS material components used for fast breeder reactor-based power plant being built at Kalpakkam, India.

The tribological properties such as surface hardness, friction and wear have been studied for AISI 316L stainless steel substrates which were co‐ion implanted with zirconium and oxygen ions. It is found that the wear resistance for AISI 316L stainless steel substrates implanted with zirconium and oxygen ions increased quite a lot. It is concluded that the increase in surface microhardness and the decrease in friction coefficient of AISI 316L stainless steel substrates play an important role in improving the wear resistance, and the relationship between relative wear volume and microhardness is correlated for zirconium and oxygen co‐ion implantation.

This paper aims to present the way of modifying surfaces of 316L stainless steel elements that were manufactured in the selected laser melting (SLM) technology and then subjected to mechanical and electrolytic processing (electropolishing [EP]). The surface of the as-generated and commercial produced parts was modified by grinding and EP, and the results were compared. The authors also present an example of the application of EP for the final processing of a sample technological model – an initial prototype of a 316L steel implant manufactured in the SLM technology.

The analyzed properties included surface topography, roughness, resistance to corrosion, microhardness and the chemical composition of the surface before and after EP. The roughness described with the Ra, Rt and Rz was determined before and after EP of samples manufactured from 316L steel with use of traditional methods and additive technologies.

EP provides us with the opportunity to process elements with a complex structure, which would not be possible with use of other methods (such as milling or grinding). Depending on the expected final surface of elements after the SLM process, it is possible to reduce the surface roughness with the use of EP (for t = 20 min, Ra = 3.53 ± 0.37 µm and for t = 40 min, Ra = 3.23 ± 0.22 µm) or mechanical processing and EP (for t = 4 min, Ra = 0.13 ± 0.02 µm). The application of the EP method to elements made from 316L steel, in a bath consisting of sulfuric acid (VI), H2SO4 (35 Vol.%), phosphoric acid (V), H3PO4 (60.5 Vol.%) and triethanolamine 99 per cent (4.5 Vol.%), allows us to improve the surface smoothness and to obtain a value of the Ra parameter ranging from 0.11 to 0.15 µm. The application of a current density of 20 A/dm2 and a bath temperature of 55ºC results in an adequate smoothing of the surface (Ra < 0.16 µm) for both cold rolled and SLM elements after grinding. The application of EP, to both cold rolled elements and those after SLM, considerably improves the resistance to corrosion. The results of potentiodynamic corrosion resistance tests (jkor, EKA and Vp) of the 316L stainless steel samples demonstrate that the values of Vp for elements subjected to EP (commercial material: 1.3·10-4 mm/year, SLM material: 3.5·10-4 mm/year) are lower than for samples that were only ground (commercial material: 4.0·10-4 mm/year, SLM material: 9.6·10-4 mm/year). The microhardness was found to be significantly higher in elements manufactured using SLM technology than in those cold rolled and ground. The ground 316L steel samples were characterized by a microhardness of 318 HV (cold rolled) and 411 HV (SLM material), whereas the microhardness of samples subjected to EP was 230 HV (commercial material) and 375 HV (SLM material).

The 316L samples were built by SLM method. The surface of the SLM samples was modified by EP. Surface morphological changes after EP were studied using optical methods. Potentiodynamic tests enabled to notice changes in the corrosion resistance of 316L. Microhardness results after electropolished 316L stainless steel were shown. The chemical composition of 316L surface samples was presented. The smoothening of the surface amounted to Ra = 0.16 µm.

In this study, powder mixed electro discharge machining (PMEDM) has been performed for the machining of AISI 304 stainless steel by using the tungsten carbide electrode when silicon carbide (SiC) powder is mixed with kerosene. The purpose of this study is to find the optimal value and ascertain the effect of significant machining parameters on surface crack density (SCD) of a machined surface of AISI 304.

A face-centered central composite design-based response surface methodology has been adopted for designing this experiment.

An increase in peak current and powder concentration decreases SCD, which is the main goal of this investigation.

From this investigation, an optimal value has been achieved to minimize the SCD and prevent fatigue and corrosion resistance of the workpiece.

The purpose of this paper is to review the state of the art of laser powder deposition (LPD), a solid freeform fabrication technique capable of fabricating fully dense functional items from a wide range of common engineering materials, such as aluminum alloys, steels, titanium alloys, nickel superalloys and refractory materials.

The main R&D efforts and the major issues related to LPD are revisited.

During recent years, a worldwide series of R&D efforts have been undertaken to develop and explore the capabilities of LPD and to tap into the possible cost and time savings and many potential applications that this technology offers.

These R&D efforts have produced a wealth of knowledge, the main points of which are highlighted herein.

The aim of this study is to present an experimental research on a Al₂O₃ · TiO₂ plasma coating on AISI 316 stainless steel substrate with and without SiC particulate reinforcement to show how SiC particulate effect on the hardness, wear resistance and microstructure of the coating.

The main objective of the paper is to investigate the effect of SiC particulate on the coating properties such as hardness, wear resistance and microstructure. Achieving of this purpose, harness and sliding test, surface roughness measurements were carried out. In addition to that parallel work on microstructural examination by optical microscope were also conducted. Owing to SiC particulate is harder than Al₂O₃ · TiO₂ plasma coating, it influence hardness and tribological behavior and result in increasing in hardness values and wear resistance of the coating reinforced with SiC particulate compare with unreinforced Al₂O₃ · TiO₂ plasma coating.

This study provides experimental results about the Al₂O₃ · TiO₂ plasma coating with and without SiC_p reinforcement. The obtained experimental results indicate that SiC_p in the coating is influence hardness, wear resistance and microstructure of the coating and make them much harder and having wear resistance. This result is consisted with the values obtained previous studies that is available in literature.

SEM or TEM studies may be needed for better understanding of wear mechanism. Various percentage of SiC particulate in the coating can be used in the further researches and provide more detailed information about effecting on SiC_p reinforcement of the coating.

The results show that SiC_p reinforcement contribute increasing in hardness and wear resistance of the coating. Those compositions of the coating can easily used in related industrial applications.

This paper fulfils some useful information about SiC_p Al₂O₃ · TiO₂ plasma coating and offers practical help to students, related academicians and researchers in the industry.