scholarly journals The use of multiple pseudo-physiological solutions to simulate degradation behavior of pure Fe: towards a standard static immersion test

2016 ◽  
Vol 4 ◽  
Author(s):  
Tolouei Ranna ◽  
Paternoster Carlo ◽  
Chevallier Pascale ◽  
Turgeon Stephane ◽  
Mantovani Diego
Keyword(s):  
Immersion Test ◽  
Degradation Behavior ◽  
Static Immersion

Microstructure and degradation behavior of forged Fe–Mn–Si alloys

2015 ◽  
Vol 29 (10n11) ◽  
pp. 1540014 ◽  
Author(s):  
Zhigang Xu ◽  
Michael A. Hodgson ◽  
Peng Cao
Keyword(s):  
Hot Forging ◽  
Immersion Test ◽  
General Corrosion ◽  
Degradation Behavior ◽  
Homogenization Treatment ◽  
Arc Melting ◽  
Cast Alloys ◽  
Degradable Biomaterials ◽  
Si Content ◽  
Static Immersion

This work presents a comparative study of a series of Fe – Mn – Si alloys proposed as degradable biomaterials for medical applications. Five Fe -28wt.% Mn -x Si (where x = 0 to 8 wt.%) alloys were fabricated by an arc-melting method. All the as-cast alloys were subsequently subjected to homogenization treatment and hot forging. The microstructure and phase constituents were investigated. It is found that the grain size of the as-forged alloys ranged approximately from 30 to 50 μm. The as-forged Fe – Mn – Si alloys containing Si from 2 to 6 wt.% was comprised of duplex martensitic ε and austenitic γ phases; however, the Si -free and 8 wt.% Si alloys only consisted of a single γ phase. After 30 days of static immersion test in a simulated body fluid (SBF) medium, it is found that pitting and general corrosion occur on the sample surfaces. Potentiodynamic analysis reveals that the degradation rate of the Fe – Mn – Si alloys increased gradually with Si content up to 6 wt.%, beyond which the degradation slows down.

scholarly journals Evolution of the ε and γ phases in biodegradable Fe–Mn alloys produced using laser powder-bed fusion

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Črtomir Donik ◽  
Jakob Kraner ◽  
Aleksandra Kocijan ◽  
Irena Paulin ◽  
Matjaž Godec
Keyword(s):  
Laser Power ◽  
Scanning Speed ◽  
Immersion Test ◽  
Pure Metal ◽  
Corrosion Stability ◽  
Powder Bed ◽  
Ε Phase ◽  
Mn Content ◽  
Static Immersion ◽  
Comprehensive Study

AbstractThe key feature of Fe–Mn alloys is gradual degradability and non-magneticity, with laser power bed fusion (LPBF) parameters influencing the microstructure and chemical composition. Our study focuses on biodegradable Fe–Mn alloys produced by mechanically mixing pure metal feedstock powders as part of the LPBF process. The Mn content and, consequently, the γ-ε phase formation in LPBF samples are directly correlated with an adapted energy–density (E) equation by combining the five primary LPBF parameters. We varied laser power (P) in a range of 200–350 W and scanning speed at 400 and 800 mm/s, and a comprehensive study was performed on samples with similar E. The study also showed an almost linear correlation between the LPBF's laser power and the material's hardness and porosity. The corrosion resistance was significantly reduced (from 13 to 400 μm/year) for the LPBF samples compared to a conventionally produced sample due to the dual-phase microstructure, increased porosity and other defects. The static immersion test showed that the process parameters greatly influence the quantity of oxides and the distribution of their diameters in the LPBF samples and, therefore, their corrosion stability. The most challenging part of the study was reducing the amount of ε phase relative to γ phase to increase the non-magnetic properties of the LPBF samples.

scholarly journals Evaluation of a Zn–2Ag–1.8Au–0.2V Alloy for Absorbable Biocompatible Materials

Materials ◽  
2019 ◽  
Vol 13 (1) ◽  
pp. 56 ◽  
Author(s):  
Ping Li ◽  
Christine Schille ◽  
Ernst Schweizer ◽  
Evi Kimmerle-Müller ◽  
Frank Rupp ◽  
...  
Keyword(s):  
Biofilm Formation ◽  
Antibacterial Properties ◽  
Microstructural Characterization ◽  
Immersion Test ◽  
Grain Refining ◽  
Degradation Behavior ◽  
New Generation ◽  
Phosphate Buffered Saline ◽  
Zn Alloy

Zinc (Zn) and Zn-based alloys have been proposed as a new generation of absorbable metals mainly owing to the moderate degradation behavior of zinc between magnesium and iron. Nonetheless, mechanical strength of pure Zn is relatively poor, making it insufficient for the majority of clinical applications. In this study, a novel Zn–2Ag–1.8Au–0.2V (wt.%) alloy (Zn–Ag–Au–V) was fabricated and investigated for use as a potential absorbable biocompatible material. Microstructural characterization indicated an effective grain-refining effect on the Zn alloy after a thermomechanical treatment. Compared to pure Zn, the Zn–Ag–Au–V alloy showed significantly enhanced mechanical properties, with a yield strength of 168 MPa, an ultimate tensile strength of 233 MPa, and an elongation of 17%. Immersion test indicated that the degradation rate of the Zn–Ag–Au–V alloy in Dulbecco’s phosphate buffered saline was approximately 7.34 ± 0.64 μm/year, thus being slightly lower than that of pure Zn. Biocompatibility tests with L929 and Saos-2 cells showed a moderate cytotoxicity, alloy extracts at 16.7%, and 10% concentration did not affect metabolic activity and cell proliferation. Plaque formation in vitro was reduced, the Zn–Ag–Au–V surface inhibited adhesion and biofilm formation by the early oral colonizer Streptococcus gordonii, indicating antibacterial properties of the alloy.

Degradation of Mechanically Surface Treated AZ31B Magnesium Alloy in 3.5 wt.% NaCl Solution

2019 ◽  
Vol 948 ◽  
pp. 237-242 ◽  
Author(s):  
Budi Arifvianto ◽  
Suyitno ◽  
Muslim Mahardika
Keyword(s):  
Magnesium Alloy ◽  
Immersion Test ◽  
Mg Alloy ◽  
Surface Mechanical Attrition Treatment ◽  
Degradation Behavior ◽  
Nacl Solution ◽  
Az31b Magnesium Alloy ◽  
Mechanical And Tribological Properties ◽  
Weight Losses ◽  
Mechanical Attrition

Surface mechanical attrition treatment (SMAT) has so far been used as a technique for improving mechanical and tribological properties of magnesium and its alloys. However, the effects of the SMAT on corrosion and degradability of these materials are still rarely reported in open literature. In this research, the degradation behavior of AZ31B magnesium alloy after receiving the SMAT was characterized. The degradation behavior of the Mg alloy was determined from the weight losses after an immersion test for 24 h in 3.5 wt.% NaCl solution. During the test, the pH of the solution was also monitored. The results obviously showed higher corrosion rates of the Mg alloy that had been treated by using the SMAT. Interestingly, the degradation rate of the Mg alloy decreased once a longer duration of SMAT was applied. Meanwhile, the pH of NaCl solution increased up to 12 and 13.9 once the non-treated and the SMAT specimens were immersed into the solution, respectively. In addition, the energy dispersive X-ray spectroscopy (EDS) analysis confirmed the presence of corrosion products in all the Mg samples that were similar to those revealed in the literature.

A Laboratory Study of N-Oleoyl Sarcosine As a Rust Inhibitor in Some Petroleum Products★

CORROSION ◽  
1957 ◽  
Vol 13 (10) ◽  
pp. 92-96 ◽  
Author(s):  
ROBERT M. PINES ◽  
JOHN D. SPIVACK
Keyword(s):  
Sea Water ◽  
Water Drop ◽  
Immersion Test ◽  
Petroleum Products ◽  
Laboratory Studies ◽  
Turbine Oil ◽  
Static Water ◽  
Water Drop Test ◽  
Rust Inhibitor ◽  
Static Immersion

Abstract Laboratory studies indicate that N-oleoyl sarcosine (I) is an effective oil soluble rust inhibitor in solution in gasoline, mineral oil and silicone lubricants. Rusting tests used included: Turbine Oil Rusting Test (ASTM D665-54), a Static Immersion Test, Humidity Cabinet Test (JAN H-792), Static Water Drop Test (MIL-L-17353 Bu. Ord.). In addition, a number of auxiliary tests were run to indicate the effect of (I) on other properties of the test liquid. Hydrocarbon solutions of N-oleoyl sarcosine are particularly effective in preventing rusting in the presence of synthetic sea water and in resisting water extraction of the inhibitor. 5.8.2

Degradation Behavior of Tungsten in Molten Aluminum

2011 ◽  
Vol 415-417 ◽  
pp. 2262-2266
Author(s):  
Hong Feng Luo ◽  
Jing Wu ◽  
Yu Deng ◽  
Wei Ping Chen
Keyword(s):  
Activation Energy ◽  
Weight Loss ◽  
Intermetallic Compound ◽  
Corrosion Rate ◽  
Thermal Stresses ◽  
Molten Aluminum ◽  
Intermetallic Layer ◽  
Degradation Behavior ◽  
Static Immersion

Corrosion of tungsten in molten aluminum was investigated by static immersion tests at 700, 750 and 800°C temperature for 8-120 h. In all cases, the Al3W intermetallic compound was formed. The intermetallic layer broke up as long as it grew due to thermal stresses and dispersed in the molten aluminum. The weight-loss of tungsten varied linearly with time. The corrosion rate increased with temperature and the activation energy was nearly 87.92 kJ mol-1.

scholarly journals Corrosion Behavior of Zn, Fe and Fe-Zn Powder Materials Prepared via Uniaxial Compression

Materials ◽  
2021 ◽  
Vol 14 (17) ◽  
pp. 4983
Author(s):  
Radka Gorejová ◽  
Ivana Šišoláková ◽  
Pavol Cipa ◽  
Róbert Džunda ◽  
Tibor Sopčák ◽  
...  
Keyword(s):  
Corrosion Behavior ◽  
Energy Dispersive Spectrometry ◽  
Weight Ratio ◽  
Powder Materials ◽  
Degradation Behavior ◽  
Electrochemical Polarization ◽  
Pure Zinc ◽  
Iron And Zinc ◽  
Scanning Electron ◽  
Static Immersion

Powder metallurgy is one of the most prevalent ways for metallic degradable materials preparation. Knowledge of the properties of initial powders used during this procedure is therefore of great importance. Two different metals, iron and zinc, were selected and studied in this paper due to their promising properties in the field of biodegradable implants. Raw powders were studied using scanning electron microscopy (SEM) coupled with energy dispersive spectrometry (EDX). Powders (Fe, Zn and Fe-Zn in a weight ratio of 1:1) were then compressed at the pressure of 545 MPa to the form of pellets with a diameter of 1.7 cm. Surface morphology and degradation behavior in the Hanks´ solution were studied and evaluated. Electrochemical polarization tests along with the static immersion tests carried out for 21 days were employed for corrosion behavior characterization. The highest corrosion rate was observed for pure Zn powder followed by the Fe-Zn and Fe, respectively. A mixed Fe-Zn sample showed similar properties as pure zinc with no signs of iron degradation after 21 days due to the effect of galvanic protection secured by the zinc acting as a sacrificial anode.

Using Hydrodynamic Testing to Assess the Performance of Five Fouling Control Coatings Immersed at Two Field Sites along the East Coast of Florida

2017 ◽  
Author(s):  
J. Travis Hunsucker ◽  
Harrison Gardner ◽  
Geoffrey Swain
Keyword(s):  
High Speed ◽  
East Coast ◽  
Immersion Test ◽  
Fouling Control ◽  
Drag Forces ◽  
Fouling Release ◽  
Fouling Control Coatings ◽  
Fouling Organisms ◽  
Hydrodynamic Testing ◽  
Static Immersion

Static immersion studies are commonly used to assess the performance of fouling control coatings. While these tests provide valuable data, it is also of importance to understand the drag forces associated with the accrued fouling communities and the velocities required for fouling removal. Combining the measurements of hydrodynamic testing with those from static immersion testing can help in predicting the performance of coatings prior to their consideration for use on Navy vessels. Replicates of five commercially available coatings (three fouling release coatings and two biocide based coatings) were deployed at two static immersion test sites located along the east coast of Florida (Port Canaveral and Sebastian Inlet). After four months of immersion, the panels were removed, photographed, subjected to known water velocities in a high-speed boat modified for hydrodynamic testing. Each panel was run at 5 m/s for 10 minutes, photographed, and then run at 10 m/s for 10 minutes. The drag forces were measured at speeds of 3, 6, 8.8 and 10 m/s for 1 minute each. Photographs taken before, during, and after hydrodynamic testing were also visually analyzed. After testing adhesion measurements were taken to determine the attachment strength of any hard fouling organisms which remained on the panels. The data collected from this series of tests, enabled the fouling control and fouling release properties of each coating to be characterized.

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