scholarly journals Microstructural and Corrosion Properties of Ti-to-Zr Dissimilar Alloy Joints Brazed with a Zr-Ti-Cu-Ni Amorphous Filler Alloy

Metals ◽  
2021 ◽  
Vol 11 (2) ◽  
pp. 192
Author(s):  
Si-Young Lee ◽  
Hyun-Jun Lee ◽  
Jong-Hee Baek ◽  
Sung Soo Park ◽  
Jung Gu Lee
Keyword(s):  
Galvanic Corrosion ◽  
Intermetallic Phase ◽  
Isothermal Solidification ◽  
Corrosion Property ◽  
Holding Time ◽  
Localized Corrosion ◽  
Filler Alloy ◽  
Corrosion Properties ◽  
Brazed Joints ◽  
Joint Center

Titanium and Zircaloy-4 dissimilar alloys were brazed with a zirconium-titanium-copper-nickel amorphous filler alloy, and the resulting joint structures as well as their corrosion properties were examined. The microstructure of the brazed joints was investigated according to brazing holding time at 850 °C, and the corrosion property was analyzed by potentiodynamic polarization. During brazing, joints were produced by diffusion-induced isothermal solidification of the molten filler alloy. At a relatively brief brazing holding time of 5 min, a large segregation zone consisting of an active α-phase and a nobler intermetallic phase was generated in the joint center, which suffered from micro-galvanic corrosion. The presence of alloyed titanium deteriorated the nobility of the α-zirconium phase near the joint and induced galvanic coupling with cathodic base metals, resulting in massive localized corrosion. This localized corrosion caused the pitting behavior at the applied potential of −51.1~187.5 mV during anodic polarization. With a brazing holding time of 20 min, the concentration of the alloying elements was homogenized to eliminate the electrochemical potential difference and minimize the galvanic corrosion susceptibility of the joint region. This homogeneous joint resulted in a highly passive corrosion behavior comparable to that of the titanium base metal.

Effects of Surface Oxide Coating on Corrosion Behavior of Ti-1023/LY12 Galvanic Couple

2013 ◽  
Vol 668 ◽  
pp. 880-884 ◽  
Author(s):  
Jun Xiu Shi ◽  
Jian Hua Liu
Keyword(s):  
Corrosion Behavior ◽  
Galvanic Corrosion ◽  
Oxide Coating ◽  
Optical Microscope ◽  
Open Circuit ◽  
Localized Corrosion ◽  
Corrosion Attack ◽  
Corrosion Properties ◽  
Corrosion Morphology ◽  
Galvanic Couple

Galvanic corrosion behavior of Ti-1023 titanium alloy coupled to LY12 aluminum alloy was investigated in 3.5% NaCl solution. Particular attention was given to the effect of anodized coatings on corrosion behaviors of Ti-1023/LY12 galvanic couple. Galvanic test was conducted on the following couples: Ti-1023/LY12, Ti-1023/anodized LY12 and anodized Ti-1023/anodized LY12, respectively. Corrosion properties including open circuit potential (Eoc) of each material, galvanic corrosion potential (Eg) and galvanic corrosion current (Ig) of the couples were monitored. Corrosion morphology was observed by optical microscope (OM) and corrosion mechanisms were analyzed and discussed. It was showed that anodized coatings significantly decreased Eg and Īg of the couples and provide effective protection of the anode from suffering corrosion attack. Only slight localized corrosion was detected on anodized LY12 alloy in the two anodized couples and the LY12 in anodized Ti-1023/anodized LY12 couple was found to be least susceptible to galvanic corrosion. The LY12 alloy in the bare couple: Ti-1023/LY12, was found to be highly susceptible to galvanic corrosion and suffered severe uniform and localized corrosion attack

scholarly journals Effect of Manganese on Microstructure and Corrosion Behavior of the Mg-3Al Alloys

Metals ◽  
2019 ◽  
Vol 9 (4) ◽  
pp. 460 ◽  
Author(s):  
Yao ◽  
Liu ◽  
Zeng ◽  
Li ◽  
Lei ◽  
...  
Keyword(s):  
Corrosion Resistance ◽  
Corrosion Behavior ◽  
Galvanic Corrosion ◽  
Intermetallic Phase ◽  
Localized Corrosion ◽  
Experimental Investigations ◽  
X Ray Diffraction ◽  
X Ray ◽  
Electrochemical Tests ◽  
Microstructure Observation

Microstructure and corrosion behavior of the Mg-3Al-xMn (x = 0, 0.12, 0.21, 0.36, 0.45) (hereafter in wt.%) alloys were experimentally investigated by electron probe microanalysis (EPMA), scanning electron microscope equipped with energy dispersive X-ray spectroscopy (SEM/EDX), X-ray diffraction (XRD), electrochemical, and hydrogen evolution tests. A new self-constructed Mg-Al-Mn-Fe thermodynamic database was used to predict the solidification paths of the alloys. The addition of Mn showed no grain refinement in the cast Mg-3Al alloys. According to the microstructure observation, Al-Fe phases were observed in the non-Mn-added alloy, while Al8Mn5(LT) (Al8Mn5 in low temperature) became the main intermetallic phase in the Mn-added alloys, and the amount increased gradually with the Mn addition. The τ–Al0.89Mn1.11 phase with lower Al/(Fe + Mn) ratio was observed in the alloys with 0.36 and 0.45 wt.% Mn content. According to the electrochemical tests, all five alloys showed localized corrosion characteristics in 3.5 wt.% NaCl solution. Compared with the Mg-3Al alloy, the corrosion resistance of Mn-added alloys were significantly improved and increased gradually with the Mn addition, which was due to the variation of Al-containing intermetallic compounds. The present experimental investigations and thermodynamic calculations confirmed the mechanism that the increasing amount of Al8Mn5(LT) with Mn addition could encapsulate the B2-Al(Mn,Fe) phase with higher Fe. Therefore, it could prevent this detrimental phase from contacting magnesium matrix, thus suppressing micro-galvanic corrosion and improving corrosion resistance gradually.

scholarly journals New Zn3Mg-xY Alloys: Characteristics, Microstructural Evolution and Corrosion Behavior

Materials ◽  
2021 ◽  
Vol 14 (10) ◽  
pp. 2505
Author(s):  
Catalin Panaghie ◽  
Ramona Cimpoeșu ◽  
Bogdan Istrate ◽  
Nicanor Cimpoeșu ◽  
Mihai-Adrian Bernevig ◽  
...  
Keyword(s):  
Galvanic Corrosion ◽  
Intermetallic Phase ◽  
Young Modulus ◽  
Induction Melting ◽  
X Ray Diffraction ◽  
Medical Field ◽  
Pure Zinc ◽  
X Ray ◽  
Knowing That ◽  
Master Alloys

Zinc biodegradable alloys attracted an increased interest in the last few years in the medical field among Mg and Fe-based materials. Knowing that the Mg element has a strengthening influence on Zn alloys, we analyze the effect of the third element, namely, Y with expected results in mechanical properties improvement. Ternary ZnMgY samples were obtained through induction melting in Argon atmosphere from high purity (Zn, Mg, and Y) materials and MgY (70/30 wt%) master alloys with different percentages of Y and keeping the same percentage of Mg (3 wt%). The corrosion resistance and microhardness of ZnMgY alloys were compared with those of pure Zn and ZnMg binary alloy. Materials were characterized using scanning electron microscopy (SEM), energy dispersive spectroscopy (EDS), X-ray diffraction (XRD), linear and cyclic potentiometry, and immersion tests. All samples present generalized corrosion after immersion and electro-corrosion experiments in Dulbecco solution. The experimental results show an increase in microhardness and indentation Young Modulus following the addition of Y. The formation of YZn12 intermetallic phase elements with a more noble potential than pure Zinc is established. A correlation is obtained between the appearance of new Y phases and aggressive galvanic corrosion.

Modeling Corrosion Property of High Chromium Cast Iron under H3PO4 Medium Condition Using Artificial Intelligence

2010 ◽  
Vol 150-151 ◽  
pp. 1054-1057
Author(s):  
Song Min Zhang ◽  
Liu Jie Xu
Keyword(s):  
Neural Network ◽  
Weight Loss ◽  
Cast Iron ◽  
Bp Neural Network ◽  
Corrosion Property ◽  
Corrosion Properties ◽  
High Chromium ◽  
High Chromium Cast Iron ◽  
Chromium Cast Iron ◽  
Corrosion Time

The components in slurry pump suffer serious corrosion and abrasion in the phosphorus fertilizer manufacturing process because they undergo corrosion of H3PO4 medium and impact of particles at the same time. Presently, High chromium cast irons are often used to produce the components in slurry pump. In order to reveal the corrosive law, the corrosion properties of high chromium cast iron with 26wt.%Cr content (Cr26) were tested under different H3PO4 medium concentration conditions. Using back-propagation (BP) neural network, the non-linear relationship between the corrosion weight losses (W) and H3PO4 concentration, corrosion time (C, t) is established on the base of the dealing with experimental data. The results show that the well-trained BP neural network can predict the wear weight loss precisely according to H3PO4 concentration and corrosion time. The prediction results reveal that corrosion weight loss rises linearly with increasing corrosion time. The H3PO4 concentration has obvious effect on corrosion property. When H3PO4 concentration is lower than about 0.5mol/L, high chromium cast iron has well resistance to H3PO4 corrosion. However, the corrosion resistance of high chromium cast iron rapidly decreases when the H3PO4 concentration exceed about 0.8 mol/L. It is suggest the high chromium cast iron be used under the condition of H3PO4 concentration of lower 0.8 mol/L.

High-Temperature Brazing Molybdenum

2012 ◽  
Vol 586 ◽  
pp. 69-73
Author(s):  
Chia Chen Lin ◽  
Cheng Han Lee ◽  
Ren Kae Shiue ◽  
Hsiou Jeng Shy
Keyword(s):  
High Temperature ◽  
Intermetallic Phase ◽  
High Temperature Application ◽  
Three Point Bending ◽  
Brazed Joints ◽  
Temperature Application ◽  
Titanium Foils

High-temperature brazing molybdenum using palladium and titanium foils have been investigated in the experiment. Successful brazed joints are achieved from using the palladium filler foil. Brazed joints are fully dense and free of any intermetallic phase. Three point bending strengths of 246 and 233 MPa are obtained from joints using 100 m thick palladium filler foil brazed at 1580 and 1610 oC for 600 s, respectively. The application of palladium filler foil shows potential in brazing molybdenum for high-temperature application.

Galvanic corrosion properties of differently PVD-treated magnesium die cast alloy AZ91

2005 ◽  
Vol 193 (1-3) ◽  
pp. 223-229 ◽  
Author(s):  
H. Hoche ◽  
C. Blawert ◽  
E. Broszeit ◽  
C. Berger
Keyword(s):  
Cast Alloy ◽  
Galvanic Corrosion ◽  
Corrosion Properties ◽  
Alloy Az91 ◽  
Die Cast

Evolution of microstructure of 304 stainless steel joined by brazing process

2010 ◽  
Vol 1276 ◽  
Author(s):  
F. García-Vázquez ◽  
I. Guzmán-Flores ◽  
A. Garza ◽  
J. Acevedo
Keyword(s):  
Tensile Strength ◽  
Stainless Steel ◽  
Holding Time ◽  
304 Stainless Steel ◽  
Commercial Application ◽  
Wide Range ◽  
Unique Method ◽  
Brazed Joints ◽  
Brazed Joint ◽  
Evolution Of Microstructure

AbstractBrazing is a unique method to permanently join a wide range of materials without oxidation. It has wide commercial application in fabricating components. This paper discusses results regarding the brazing process of 304 stainless steel. The experimental brazing is carried out using a nickel-based (Ni-11Cr-3.5Si-2.25B-3.5Fe) filler alloy. In this process, boron and silicon are incorporated to reduce the melting point, however they form hard and brittle intermetallic compounds with nickel (eutectic phases) which are detrimental to the mechanical properties of brazed joints. This investigation deals with the effects of holding time and brazing temperature on the microstructure of joint and base metal, intermetallic phases formation within the brazed joint as well as measurement of the tensile strength. The results show that a maximum tensile strength of 464 MPa is obtained at 1120°C and 4 h holding time. The shortest holding times will make boron diffuse insufficiently and generate a great deal of brittle boride components.

scholarly journals Corrosion study of metallic biomaterials in simulated body fluid

10.30544/384 ◽  
2011 ◽  
Vol 17 (1) ◽  
pp. 13-22 ◽  
Author(s):  
Hamid Reza Asgari Bidhendi ◽  
Majid Pouranvari
Keyword(s):  
Stainless Steel ◽  
Simulated Body Fluid ◽  
Corrosion Behavior ◽  
Body Fluid ◽  
Pure Titanium ◽  
Localized Corrosion ◽  
Commercially Pure Titanium ◽  
Corrosion Properties ◽  
Cyclic Polarization ◽  
Cp Ti

Titanium alloys and stainless steel 316L are still the most widely used biomaterials for implants despite emerging new materials for this application. There is still someambiguity in corrosion behavior of metals in simulated body fluid (SBF). This paper aims at investigating the corrosion behavior of commercially pure titanium (CP-Ti), Ti–6Al–4V and 316LVM stainless steel (316LVM) in SBF (Hank’s solution) at37 ºC using the cyclic polarization test. Corrosion behavior was described in terms of breakdown potential, the potential and rate ofcorrosion, localized corrosion resistance, andbreakdown repassivation. The effects of anodizing on CP-Ti samples and the passivation on the 316LVM were studied in detail. It was shown that CP-Ti exhibited superior corrosion properties compared to Ti–6Al–4V and 316LVM.

scholarly journals Evaluation of Biomedical Ti/ZrO2 Joint Brazed with Pure Au Filler: Microstructure and Mechanical Properties

Metals ◽  
2020 ◽  
Vol 10 (4) ◽  
pp. 526
Author(s):  
Yuzhen Lei ◽  
Hong Bian ◽  
Wei Fu ◽  
Xiaoguo Song ◽  
Jicai Feng ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Energy Dispersive Spectrometry ◽  
Filler Metal ◽  
Interfacial Microstructure ◽  
Holding Time ◽  
X Ray Diffraction ◽  
X Ray ◽  
Medical Products ◽  
Metallurgical Bonding ◽  
Brazed Joints

Titanium and zirconia (ZrO2) ceramics are widely used in biomedical fields. This study aims to achieve reliable brazed joints of titanium/ZrO2 using biocompatible Au filler for implantable medical products. The effects of brazing temperature and holding time on the interfacial microstructures and mechanical properties of titanium/Au/ZrO2 joints were fully investigated by scanning electron microscopy (SEM), energy-dispersive spectrometry (EDS) and X-ray diffraction (XRD). The results indicated that the typical interfacial microstructure of the titanium/Au/ZrO2 joint was titanium/Ti3Au layer/TiAu layer/TiAu2 layer/TiAu4 layer/TiO layer/ZrO2 ceramic. With an increasing brazing temperature or holding time, the thickness of the Ti3Au + TiAu + TiAu2 layer increased gradually. The growth of the TiO layer was observed, which promoted metallurgical bonding between the filler metal and ZrO2 ceramic. The optimal shear strength of ~35.0 MPa was obtained at 1150 °C for 10 min. SEM characterization revealed that cracks initiated and propagated along the interface of TiAu2 and TiAu4 reaction layers.

scholarly journals Galvanic Corrosion Due to a Heterogeneous Sulfate Reducing Bacteria Biofilm

Coatings ◽  
2020 ◽  
Vol 10 (11) ◽  
pp. 1116
Author(s):  
Hongwei Liu ◽  
Haixian Liu ◽  
Yuxuan Zhang
Keyword(s):  
Galvanic Corrosion ◽  
Steel Corrosion ◽  
Localized Corrosion ◽  
Cathodic Reaction ◽  
Anodic Reaction ◽  
Sulfate Reducing ◽  
Corrosion Effect ◽  
Desulfotomaculum Nigrificans ◽  
Corrosion Of Steel ◽  
Reducing Bacteria

In this work, the galvanic corrosion behavior of sulfate reducing Desulfotomaculum nigrificans biofilm-covered and uncovered carbon steel was investigated using various electrochemical measurements. The results showed that the bare specimen in the abiotic solution functions as the anode; whereas the biofilm-covered specimen in the SRB-containing solution functions as the cathode after two electrodes being coupled. The anodic reaction of specimen in the biotic solution containing SRB was inhibited; whereas the cathodic reaction was considerably promoted after coupling. Hence, localized corrosion of specimen in the abiotic solution was observed due to the galvanic corrosion effect. SRB could still accelerate steel corrosion even after coupling, but the results indicate that the contribution of SRB to steel corrosion decreased. The localized corrosion of steel in the SRB-containing environments not only involved the SRB biofilm, but also a galvanic corrosion effect. The flow of electrons from the anodic dissolution of Fe in the abiotic solution to the SRB cells of cathodic area decreased the acceptance capacity of electrons by SRB from steel beneath biofilm. As a result, the steel corrosion beneath SRB biofilm decreased after coupling.

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