Good Combination Of Corrosion Resistance Research Articles

Investigation of Cu-doped amorphous carbon film in improving corrosion resistance and interfacial conductivity of proton exchange membrane fuel cell

This study investigated Cu-doped a-C films prepared under a substrate bias gradually reducing from 120 to 60 V and different Cu target currents of 0, 0.15, 0.2, 0.3, 0.5 A, respectively, using closed field unbalanced magnetron sputtering physical vapour deposition technique. While the Cu-doped a-C film at the lowest Cu target current of 0.15 A (A0.15) remained an amorphous microstructure, Cu nanoprecipitates occurred at Cu target currents of 0.2–0.5 A. All the Cu-doped a-C films prepared exhibited good combination of corrosion resistance to a corrosive chemical mixture of 0.5 M H2SO4 + 5 ppm HF (as suggested by the corrosion current densities) and interfacial electric conductivity (as demonstrated by the interfacial contact resistance, ICR). Among all coatings, A0.15 showed the best corrosion resistance and interfacial electric conductivity, which is attributable to the precipitate-free Cu-doped amorphous microstructure. The measured current density of A0.15 was 1.95 × 10−7 A/cm2 at 0.6 V (vs. SCE) during potentiodynamic polarization, which was lower than that of the Cu-free a-C film at 7.34 × 10−7 A/cm2. The ICR value of A0.15 was 4.40 mΩcm2 at an assembly pressure of 1.4 MPa, which is about one third of the Cu-free a-C film. This study demonstrates a new deposition strategy combining Cu-doping and the control of substrate bias to improve the corrosion resistance and interfacial electric conductivity of a-C films for PEMFC.

Towards Laser Metal Deposition of Modified PH 13-8Mo Powder

Modified PH 13-8Mo alloy exhibits a good combination of corrosion resistance and mechanical properties for demanding applications in aerospace, petrochemical, and tooling industries. Additive manufacturing, specifically the laser metal deposition process with powder as feedstock (LMDp), has the potential to be utilized in these industries. However, very limited knowledge on the LMDp of this alloy currently exists. The aim of this work was, therefore, to deposit a multi-track single layer of modified PH 13-8Mo alloy as a first step towards 3D geometries, and to analyze the resulting microstructure by using Optical Microscopy, Scanning Electron Microscopy, X-Ray Diffraction, Electron Backscatter Diffraction, and micro-hardness. It was found that the multi-track single layer was free from major defects. The microstructure was heterogeneous, and it consisted of a martensitic matrix and small amounts of δ ferrite, austenite, and AlN. The results of this research will be used to tailor the microstructure and properties of future 3D additively manufactured components.

Experiments on dynamic mechanical properties of austenitic stainless steel S30408 and S31608

Austenitic stainless steel, the most commonly used stainless steel, provides a good combination of corrosion resistance, weldability, forming and fabrication properties, and has broad application prospects in engineering structures. Engineering structures using austenitic stainless steel are at risk of seismic, impact or blast loading throughout their life-cycle. In this paper, the dynamic mechanical properties of two kinds of austenitic stainless steels (S30408 and S31608, known as 1.4301 and 1.4401 in EN10088:1, 304 and 316 in ASTM standard) were experimentally studied. Firstly, the quasi-static and dynamic stress–strain curves of S30408 and S31608 at low, medium (100–102 s−1) and high strain rates (102–104 s−1) were obtained by universal electromechanical testing machine, servo-hydraulic high-speed tensile testing machine and split Hopkinson tensile bars (SHTB), respectively. And then, based on the obtained quasi-static and dynamic stress–strain curves, the strain rate effect of strength and plasticity for S30408 and S31608 was analyzed and compared. The test results indicate that the strength of both two austenitic stainless steels shows strain rate effect, and the strain rate effect of strength for S30408 is more significant than that of S31608; however, the plasticity indexes of S31608 is better than that of S30408. Finally, the constitutive models parameters for the commonly used Cowper-Symonds and Johnson-Cook models were identified by curve-fitted method, and the corresponding material strain rate enhancement coefficient was also revised.

Special Issue: Plasma Electrolytic Oxidation (PEO) Coatings

The demand of modern technological society for light structural materials (Al, Ti, Mg) emphasizes a combination of good corrosion resistance with wear properties and functionalized surfaces [...]

Biomedical materials: A review of titanium based alloys

The sterling mechanical properties of titanium alloys have distinguished them as an essential material for varied applications especially in biomedical fields. The combination of good corrosion resistance in addition to light weight, non-toxicity and an outstanding biocompatibility makes them a sought-after material for production of medical implants. Owing to the surging demand for durable implants, it has become exigent for increased developmental researches on biomaterials to be accelerated. This will result in significant increase in implant production and Ti alloys will play a vital role among the several materials presently in use. Hence, this review critically analysed the important roles Ti alloys have played thus far in the implant production industry and recent development of titanium-based alloys with low elastic modulus similar to human bones as well as improved biocompatibility and wear resistance.

Sputtered Mg100-xZnx (0 ≤ x ≤ 100) systems as anode materials for a biodegradable battery aimed for transient bioelectronics

Transient implantable medical devices are gaining research enthusiasm as an emerging technology in biomedicine. To provide on-board powering for such devices, a biodegradable battery is a promising choice. However, the anode material in such batteries, usually Mg or its alloys, suffer from parasitic corrosion and faster discharge kinetics, that limits the lifetime of these devices. In the pursuit of finding a better anode material, herein, the idea of combinatorial development is employed to fabricate a material having a good combination of corrosion resistance and discharge characteristics, by exploring a wider Mg100-xZnx (0 ≤ x ≤ 100 at.%) system. Using magnetron co-sputtering of Mg and Zn, six Mg100-xZnx (x = 0, 6, 20, 34, 41, 100) systems are synthesized. Structural characterization of these systems via X-Ray Diffraction manifests range of microstructures, from fully crystalline to fully amorphous, governed by alloy composition and sputtering conditions. The corrosion investigation of the six systems manifests a generally improving trend upon higher addition of Zn content. Additionally, the discharge performances of the systems are investigated in Phosphate Buffered Saline (PBS) solution, an in-vitro surrogate of physiological fluid, which demonstrates that discharge performances of the sputtered anode materials can be effectively tailored via a prudent design of alloy composition and microstructure.

Development of Novel Al-Alloy (Al-5Mg)/10Wt.%TiB<sub>2</sub> Metal Matrix Composites by <i>In Situ</i> Reaction Synthesis

The present paper describes a cost effective route to produce Al alloy-10 wt % TiB2 metal matrix composites by in-situ molten flux assisted reaction synthesis. Now a days main focus is given to aluminium alloy as a matrix material due to its unique combination of good corrosion resistance, low density, superior mechanical properties, good vibration damping, higher wear resistance due to which alloy finds extensive applications in naval applications. With TiB2 as particulate addition in Al-Alloy (Al-5Mg) matrix properties of alloy can greatly be improved.

Hybrid Laser-arc Welding of 17-4 PH Martensitic Stainless Steel

PH stainless steel has wide applications in severe working conditions due to its combination of good corrosion resistance and high strength. The weldability of 17-4 PH stainless steel is challenging. In this work, hybrid laser-arc welding was developed to weld 17-4 PH stainless steel. This method was chosen based on its advantages, such as deep weld penetration, less filler materials, and high welding speed. The 17-4 PH stainless steel plates with a thickness of 19 mm were successfully welded in a single pass. During the hybrid welding, the 17-4 PH stainless steel was immensely susceptible to porosity and solidification cracking. The porosity was avoided by using nitrogen as the shielding gas. The nitrogen stabilized the keyhole and inhibited the formation of bubbles during welding. Solidification cracking easily occurred along the weld centerline at the root of the hybrid laser-arc welds. The microstructural evolution and the cracking susceptibility of 17-4 PH stainless steel were investigated to remove these centerline cracks. The results showed that the solidification mode of the material changed due to high cooling rate at the root of the weld. The rapid cooling rate caused the transformation from ferrite to austenite during the solidification stage. The solidification cracking was likely formed as a result of this cracking-susceptible microstructure and a high depth/width ratio that led to a high tensile stress concentration. Furthermore, the solidification cracking was prevented by preheating the base metal. It was found that the preheating slowed the cooling rate at the root of the weld, and the ferrite-to-austenite transformation during the solidification stage was suppressed. Delta ferrite formation was observed in the weld bead as well no solidification cracking occurred by optimizing the preheating temperature.

Role of electrolyte composition on structural, morphological and in-vitro biological properties of plasma electrolytic oxidation films formed on zirconium

Development of oxide films on metallic implants with a good combination of corrosion resistance, bioactivity and cell adhesion can greatly improve its biocompatibility and functionality. Thus, the present work is aimed to fabricate oxide films on metallic Zr by plasma electrolytic oxidation (PEO) in methodically varied concentrations of phosphate, silicate and KOH based electrolyte systems using a pulsed DC power source. The oxide films fabricated on Zr are characterized for its phase composition, surface morphology, chemical composition, roughness, wettability, surface energy, corrosion resistance, apatite forming ability and osteoblast cell adhesion. Uniform films with thickness varying from 6 to 11μm are formed. XRD patterns of all the PEO films showed the predominance of monoclinic zirconia phase. The film formed in phosphate+KOH electrolyte showed superior corrosion resistance, which can be ascribed to its pore free morphology. The films formed in silicate electrolyte showed higher apatite forming ability with good cell adhesion and spreading over its surface which is attributed to its superior surface roughness and wettability characteristics. Among the five different electrolyte systems employed in the present study, the PEO film formed in an electrolyte system with phosphate+silicate+KOH showed optimum corrosion resistance, apatite forming ability and biocompatibility.

Materials Selection for Superheater Tubes in Municipal Solid Waste Incineration Plants

Corrosion reduces the lifetime of municipal solid waste incineration (MSWI) superheater tubes more than any other cause. It can be minimized by the careful selection of those materials that are most resistant to corrosion under operating conditions. Since thousands of different materials are already known and many more are developed every year, here the selection methodology developed by Prof. Ashby of the University of Cambridge was used to evaluate the performance of different materials to be used as MSWI superheater tubes. The proposed materials can operate at steam pressures and temperatures over 40 bars and 400 °C, respectively. Two case studies are presented: one makes a balanced selection between mechanical properties and cost per thermal unit; and the other focuses on increasing tube lifetime. The balanced selection showed that AISI 410 martensitic stainless steel (wrought, hard tempered) is the best candidate with a good combination of corrosion resistance, a relatively low price (0.83-0.92 €/kg) and a good thermal conductivity (23-27 W/m K). Meanwhile, Nitronic 50/XM-19 stainless steel is the most promising candidate for long-term selection, as it presents high corrosion resistance with a relatively low price (4.86-5.14 €/kg) compared to Ni-alloys.

Effect of preparation parameters on the properties of hydroxyapatite containing micro-arc oxidation coating on biodegradable ZK60 magnesium alloy

Recently, micro-arc oxidation (MAO) is intensely studied as a promising surface treatment method for biodegradable magnesium alloys due to the excellent wear resistance and bonding strength of the MAO coating. In order to improve the bioactivity of the coating, hydroxyapatite (HA) nano-particles were added in the MAO electrolyte in the present study to prepare HA containing MAO coatings on the biodegradable ZK60 magnesium alloy. The HA concentration in the electrolyte, the preparation voltage and oxidation time were adjusted to prepare coatings with different morphologies, composition and properties. It was found that the coating was greatly influenced by these three parameters. The immersion test demonstrated that the HA containing MAO coating owned increased bioactivity and long-term protective ability compared with the base coating. A HA containing coating with good combination of corrosion resistance and phase composition could be obtained by properly selecting the above parameters.

Microstructure, mechanical and corrosion properties of Mg–Dy–Gd–Zr alloys for medical applications

In previous investigations, a Mg–10Dy (wt.%) alloy with a good combination of corrosion resistance and cytocompatibility showed great potential for use as a biodegradable implant material. However, the mechanical properties of Mg–10Dy alloy are not satisfactory. In order to allow the tailoring of mechanical properties required for various medical applications, four Mg–10(Dy+Gd)–0.2Zr (wt.%) alloys were investigated with respect to microstructure, mechanical and corrosion properties. With the increase in Gd content, the number of second-phase particles increased in the as-cast alloys, and the age-hardening response increased at 200°C. The yield strength increased, while the ductility reduced, especially for peak-aged alloys with the addition of Gd. Additionally, with increasing Gd content, the corrosion rate increased in the as-cast condition owing to the galvanic effect, but all the alloys had a similar corrosion rate (∼0.5mmyear−1) in solution-treated and aged condition.

Aluminium-Titanium Diboride (Al-TiB2) Metal Matrix Composites: Challenges and Opportunities

A review of Al based metal matrix composite reinforced with TiB2 particles developed after 1997 is presented in this paper. This paper presents an overview of Al-TiB2 MMC on aspects relating to the formation of TiB2, development of Al-TiB2, mechanical characteristics, thermodynamic calculation, wear behavior of Al-TiB2, cycle fatigue response of insitu Al based composite, processing, microstructure, properties and application are discussed. Aluminium alloys are widely used for commercial applications in the transportation, construction and similar engineering industries. Nowadays, main focus is given to Aluminium as matrix material because of its unique combination of good corrosion resistance, low electrical resistance and it possesses excellent mechanical properties in addition to good corrosion resistance due to which the alloy finds extensive application in naval vessels manufacturing. Al-TiB2 composite is a metal matrix composite (MMC) that can be manufactured using the in-situ salt-metal reaction. With TiB2 as the particulate addition the properties of Al 6061 alloy can be greatly improved. The addition of TiB2 to aluminium increases the strength of the aluminium. The wear resistance of this material is due to the lack of pull out of this material from the aluminium matix. Also, such material when machine with non–conventional methods like EDM will show better machinability due to its high conductivity. In the last few years, Al-TiB2 have been utilized in high-tech structural and functional applications including aerospace, defense, automotive, and thermal management areas, as well as in sports and recreation. The future research is summarized finally.

Development of a Processing Window for the Transformation Hardening of Nickel-Aluminium-Bronze

Nickel-Aluminium-Bronzes (NAB) are typically used in marine applications because of their good combination of corrosion resistance and strength. Even though these alloys exhibit good properties they do suffer from wear, corrosion, dealloying, cavitation corrosion-erosion or corrosion fatigue during service. Therefore methods of increasing the resistance of this class of alloy to surface sensitive damage mechanisms are desirable. Transformation hardening through laser processing offers the potential to increase the resistance of these alloys surface sensitive mechanisms of damage and increase their life. A processing window has been developed through the use of an analytical heat transfer model to determine laser processing parameters that are close to the critical temperature for surface melting. The absorption of the laser by NAB has been determined and the processing window calculated taking into account the velocity of the laser, laser spot size and type as well as laser power.

Cr–Ni–Mo–Co surface alloying layer formed by plasma surface alloying in pure iron

Using double glow plasma alloying technique, a multi-elements alloyed layer containing elements of Cr, Ni, Mo and Co was formed on the surface of pure iron. After undergoing suitable aging treatment followed solid solution treatment, the formed alloying layer keeps a good combination of corrosion resistance and wear resistance. The relationship between the process parameters of heat treatments and the properties of the formed Cr–Ni–Mo–Co alloying layer, such as the chemical composition, hardness, corrosion resistance and wear resistance, was investigated in this study. It was revealed that the formed alloying layer exhibits a better behavior than that of 304 stainless steel and pure iron by employing a suitable heat treatment system. The temperature employed in solid solution treatment is 1453 K (1180 °C) followed by water quenching and the aging temperature is 813 K (540 °C) followed by water cooling.

DOMEX 100W

Abstract Domex 100W is a weather-resistant, very high strength steel that is used for civil engineering structural components. The alloy has a good combination of corrosion resistance, strength, toughness, formability, and weldability. This datasheet provides information on composition, physical properties, and tensile properties as well as fracture toughness. It also includes information on heat treating and joining. Filing Code: SA-515. Producer or source: SSAB Swedish Steel Inc.

HPM 455

Abstract HPM 455 is a precipitation hardenable martensitic stainless steel. The composition provides a good combination of corrosion resistance and heat-treated strength favorable for fatigue applications. The material is well suited for demanding spring devices. This datasheet provides information on composition, physical properties, hardness, elasticity, and tensile properties. It also includes information on corrosion resistance as well as forming, heat treating, and joining. Filing Code: SS-666. Producer or source: Hamilton Precision Metals Inc.

BUNTING ALLOY 905

Abstract BUNTING Alloy 905 is a cast bronze bearing alloy. It is a copper-tin-zinc alloy known also as Gunmetal and 88-10-0-2 alloy. It has a good combination of corrosion resistance and strength. It is recommended for castings that are to be used under liquid or gas pressures. Its many uses include bearings, fittings and valves. This datasheet provides information on composition, physical properties, hardness, elasticity, tensile properties, and compressive strength as well as fracture toughness. It also includes information on corrosion resistance as well as casting, heat treating, machining, and joining. Filing Code: Cu-358. Producer or source: NL Industries Inc., Bearing Division.

ARMCO 22-13-5

Abstract ARMCO 22-13-5 provides an unusually good combination of corrosion resistance and strength for an austenitic stainless steel. It is nonmagnetic even after severe cold work. Common applications are in the petrochemical, chemical, pulp and paper, textile, food processing, and marine industries. This datasheet provides information on composition, physical properties, and tensile properties as well as fracture toughness and creep. It also includes information on low and high temperature performance, and corrosion resistance as well as forming, heat treating, machining, joining, and surface treatment. Filing Code: SS-252. Producer or source: Armco Steel Corporation, Advanced Materials Division.