Alloy Deposition Research Articles

Structural Properties of Zn-Fe Alloy Coatings and Their Corrosion Resistance

Single-layer and multilayer alloy deposits were coated onto a mild steel substrate by a single-bath electroplating process. The developed coating consists of Zn and Fe alloys having different compositions with different layers. The anticorrosion behavior of single-layer and multilayer deposits was evaluated by the potentiodynamic polarization method. The surface morphology of the deposits was studied with a scanning electron microscope. The crystal structure of the deposits was analyzed with the X-ray diffraction technique. The Fe content in the deposit was analyzed by a colorimeter and verified with energy-dispersive X-ray spectroscopy. The micro-hardness tester with a Vickers indenter was used to evaluate the microhardness of the developed single-layer and multilayer coatings. It was found that the microhardness increased with applied current densities. The Zn-Fe multilayer coatings with 300 layers deposited with square and triangular pulses at the applied current density of 2.0/3.0 A dm−2 were five and four times more corrosion-resistant, respectively, than the single-layer coating of the same thickness. The development of Zn-Fe coatings that are resistant to corrosion is particularly important for the automotive industry and steel-based vehicle parts.

Designing a Freestanding Electrode of Intermetallic Ni-Sn Alloy Deposit as an Anode for Lithium-Ion and Sodium-Ion Batteries

Carbon fiber (CF)-based freestanding intermetallic Ni-Sn alloy is prepared by a facile one-pot electrodeposition method and used as an anode in lithium-ion batteries (LIB) and sodium-ion batteries (SIB). Unique fern leaves-like morphology with nanotubular channels of the Sn-rich deposit of Ni-Sn@CF diminishes the challenges of large volume changes with maximum capacity utilization from Sn. Furthermore, the electro-inactive Ni phase and conductive carbon fiber backbone provide mechanical flexibility and prevent particle agglomeration during alloying/de-alloying. Electrochemistry reveals that the deposit in LIB exhibits superior C-rate performance and long-term cycling stability with an initial capacity of 984 mAh g−1 at 500 mA g−1 current density and 580 mAh g−1 capacity at the end of 500 cycles. Besides, it delivers 220 mAh g−1 capacity at 150 mAh g−1 with 77% capacity retention over 300 cycles in SIBs. This work enlightens the metal current collector-free carbon fibre-based 3D electrode designing approach toward high-performance Li-ion and Na-ion storage capability.

Laser metal deposition of self-lubricating alloys on selective laser melting maraging tools for the high temperature forming of aluminium

Selective laser melting (SLM) is an additive manufacturing technique that allows the layer-by-layer fabrication of metallic components with high dimensional tolerances, being also particularly suitable for implementing complex geometries such as cooling channels in hot forming tools. However, high temperature forming processes pose severe conditions that often require additional surface protection and functionality. The present work proposes to increase the lifetime and endurance of SLM tools using self-lubricating coatings deposited by laser metal deposition (LMD). To this end, 3D printed samples made of maraging steel prepared by SLM are functionalized with self-lubricating coatings applied by LMD. Two different metallic alloys are deposited, a nickel-based alloy containing metal sulphides and silver, and an iron-based alloy containing graphite. The resulting microstructure after the hybridization of both additive manufacturing techniques has been thoroughly analysed in terms of the microstructural changes. Afterwards, the functionalized 3D printed tools are investigated for prospective high temperature sheet metal forming of aluminium alloy AA6082 using a ring compression test rig at 300 °C, using a reference hot work tool steel as reference. The results show that the use of Ni-based self-lubricating coatings contributes to a more stable frictional behaviour, independently of the dilution of the externally added lubricant. These results serve as example for the enormous potential for the combination of laser metal deposition with selective laser melting for tool functionalization.

Parameter Optimization and Mechanism of Synchronous Wire-Powder Arc Melting Deposition of Aluminum Alloy

Parameter Optimization and Mechanism of Synchronous Wire-Powder Arc Melting Deposition of Aluminum Alloy

Electrodeposition of Iron Triad Metal Coatings: Miles to Go

The possibilities and future perspectives of electrochemical deposition of bimetallic compositions and alloys containing Fe, Co, Ni, Cr, W, and Mo are reviewed. The synthesis of two- and three-component materials, as well as compositionally more complex alloys, is considered. The method of synthesizing of materials via electrodeposition from solutions containing metal ions and metalloids is one of the most promising approaches because it is fast, cheap, and it is possible to control the composition of the final product with good precision. Corrosion, catalytic and magnetic properties should be distinguished. Due to these properties, the range of applications for these alloys is very wide. The idea of a correlation between the magnetic and catalytic properties of the iron-triad metal alloys is considered. This should lead to a deeper understanding of the interplay of the properties of electrodeposited alloys. In addition to deposition from aqueous (classical) solvents, the advantages and perspectives of electrochemical deposition from ionic liquids (ILs) and deep eutectic solvents (DES) are briefly discussed. The successful use and development of this method of electrodeposition of alloys, which are quite difficult or impossible to synthesize in classical solvents, has been demonstrated and confirmed.

The Surface Properties of Implant Materials by Deposition of High-Entropy Alloys (HEAs).

High-entropy alloys (HEAs) contain more than five alloying elements in a composition range of 5-35% and with slight atomic size variation. Recent narrative studies on HEA thin films and their synthesis through deposition techniques such as sputtering have highlighted the need for determining the corrosion behaviors of such alloys used as biomaterials, for example, in implants. Coatings composed of biocompatible elements such as titanium, cobalt, chrome, nickel, and molybdenum at the nominal composition of Co30Cr20Ni20Mo20Ti10 were synthesized by means of high-vacuum radiofrequency magnetron (HVRF) sputtering. In scanning electron microscopy (SEM) analysis, the coating samples deposited with higher ion densities were thicker than those deposited with lower ion densities (thin films). The X-ray diffraction (XRD) results of the thin films heat treated at higher temperatures, i.e., 600 and 800 °C, revealed a low degree of crystallinity. In thicker coatings and samples without heat treatment, the XRD peaks were amorphous. The samples coated at lower ion densities, i.e., 20 µAcm-2, and not subjected to heat treatment yielded superior results in terms of corrosion and biocompatibility among all the samples. Heat treatment at higher temperatures led to alloy oxidation, thus compromising the corrosion property of the deposited coatings.

High layer thickness laser directed energy deposition of Ti6Al4V alloy: Microstructure, fatigue behavior and fractography

Fatigue failure is one of the major reasons for part failure which also applies to parts manufactured by laser directed energy deposition (LDED). A high layer-thickness LDED will significantly improve the manufacturing time. The present study explores the high-layer thickness LDED of Ti6Al4V alloy with focus interests on microstructure, fatigue behavior, and fractography of the samples. Proper deposition of the material was observed with small voids in the boundary between the initial peripheral deposition and alternate 45° scanning pattern. The surface cracks which are common to welding and additive manufacturing processes were minimized after polishing. An initial increase of 61.4% in fatigue life from specimens 1 to 2, with a life cycle of 5863 and 9466, respectively, was observed. A 15.6% and 25.7% decrease from specimens 2 to 3 and specimens 3 to 4 were observed. The decreased performance in specimens 3&4 is due to the over-melting inducing coarser grain that resulted in the trans-granular crack formation with increased crack points on these samples. Ductile fatigue failure was observed after the fractography with a clear crack initiation point and ductile crack propagation. River lines, voids, and clear crack propagation marks were also observed. The performance of the current high-layer thickness LDED process was found to be within the performance of the currently reported literature, and some have better performance, while some have inferior performance than the current study.

Microstructure, micro-hardness and tensile properties of Ti6Al4V manufactured by high layer-thickness wire-feed multi-laser directed energy deposition

Microstructure and micro-hardness of Ti6Al4V samples manufactured by high-layer thickness laser-directed energy deposition (LDED) were analyzed. Microstructural analysis showed surface cracks on as-printed surfaces due to high-temperature gradient and small voids in border area between initial periphery deposition and alternate 450 deposition path. Further analysis showed overall uniform distribution of elements except for some concentrated C deposition, as confirmed by EDX mapping. Results showed micro-hardness ranging from 370.9 HV to 308.8 HV on top surface and 314.5 HV to 356.5 HV for cross-sectional surface. After the tensile test, yield stress followed a decreasing trend from 805 MPa to 710 MPa for samples 1 to 4 respectively and a similar pattern was also observed in the case of UTS ranging from 845.37 MPa to 749.9 MPa for samples 1 to 4 respectively. The present study showed proper deposition of Ti6Al4V alloy during high layer-thickness LDED manufacturing that can significantly reduce manufacturing time.

3D printing of fine-grained aluminum alloys through extrusion-based additive manufacturing: Microstructure and property characterization

• A new extrusion-based solid-state metal additive manufacturing method was developed. • The new method enables direct deposition of fine-grained aluminum alloy without melting. • The new method uses off-the-shelf metal rods rather than pricy powders as feedstock. • The printing process was completed in an open-air environment, avoiding costly inert or vacuum conditions. • The printed 6061 aluminum alloys yield the strength and ductility comparable to wrought 6061 aluminum alloys. Additive manufacturing (AM) has the potential to transform manufacturing by enabling previously unthinkable products, digital inventory and delivery, and distributed manufacturing. Here we presented an extrusion-based metal AM method (refer to “SoftTouch” deposition in the filed patent) that is suitable for making the metal feedstock flowable prior to the deposition through dynamic recrystallization induced grain refinement at elevated temperatures. The flowable metal was extruded out of the printer head like a paste for building dense metal parts with fine equiaxed grains and wrought mechanical properties. Off-the-shelf metal rods were used as feedstock and the printing process was completed in an open-air environment, avoiding pricy powders and costly inert or vacuum conditions. The resulting multi-layer deposited 6061 aluminum alloys yield the strength and ductility comparable to wrought 6061 aluminum alloys after the same T6 heat treatment. The extrusion-based metal AM method can also be advanced as green manufacturing technologies for fabricating novel alloys and composites, adding novel features to existing parts, repairing damaged metal parts, and welding advanced metals for supporting sustainable manufacturing, in addition to being developed into a cost-effective manufacturing process for the fabrication of dense metal of complex structural forms.

Wire-based directed energy deposition of a novel high-performance titanium fiber-reinforced Al5183 Aluminum Alloy

Wire-based directed energy deposition of a novel high-performance titanium fiber-reinforced Al5183 Aluminum Alloy

Investigation of Al-induced electroless cobalt–tin alloy deposition on Cu substrate

Investigation of Al-induced electroless cobalt–tin alloy deposition on Cu substrate

An integrated ANN and design of experiments technique to optimize the FSW input parameters of novel interlock lap weld

Friction stir welding of lightweight aluminium alloys have advantage in automobile industry with its vast applications. This research work focuses on the influence of FSW process parameters on novel interlock lap weld of AA7075-T7-AA7475 tailor welded blank. Three levels of the parameters, including tool rotation speed (TRS), weld speed (WS) and plunge speed, were used to form L27 orthogonal array to optimize the input process conditions. Ultimate tensile strength and Vicker's micro hardness were measured to test the characteristics of the interlock welded samples. Scanning electron microscopy analyses have been carried out to study the surface morphologies and elemental components in the welded samples. Artificial neural network (ANN) has been used to predict the optimized process parameter associated with the novel interlock lap weld. The TRS and WS contributed significantly in improving the mechanical behaviour and microstructural characteristics of interlock lap welds. Visual inspection and surface morphology analysis showed uniform dispersal of aluminium alloy deposition throughout the interlock weld samples. The ultimate tensile strength and micro hardness prediction was carried out using ANN with 95% accuracy level. The predicted results of ANN were more accurate than the experimental results and regression model of fractional factorial design. The defined FSW interlock lap weld stands out as the substitute for typical FSW lap weld of aluminium alloys which fulfils the modern automotive industry demands in welding monocock frames.

Novel Assessment Methodology for Laser Metal Deposition of New Metallic Alloys.

Metal additive manufacturing technologies are gaining great interest. However, the existing metallic alloys are generally formulated for conventional manufacturing processes. Thus, it is necessary to adapt their chemical composition or develop new alloys for the manufacturing conditions of additive manufacturing processes. The main method for manufacturing metal powder is gas atomization, but it is very expensive with long manufacturing times. Therefore, it is necessary to develop alloy validation methods that simplify the development process of new alloys. This paper deals with a methodology based on thermodynamic heat transfer equations, simulation, and powderless tests. This novel methodology enabled the determination of the optimal conditions for the laser melting deposition process of the commercial AA7075 alloy with a reduced number of experimental tests with powder, reducing the difficulties inherent to powder processing. The developed process was divided into two stages. In the first stage, the heating of the substrate was studied. In the second stage, the depositions of single tracks were validated with the parameters extrapolated from the previous stage. Hence, it was possible to manufacture single tracks free of cracks with an adequate aspect ratio.

Investigation on the relationships among process parameters, molten pool characteristics, and fabrication quality of Ti-10V-2Fe-3Al by laser direct energy deposition

Ti-10 V-2Fe-3Al (Ti-1023) titanium alloy is a metastable high-strength β titanium alloy. Defects such as spatters, pores, and poor surface quality tend to occur during the laser direct energy deposition (LDED) of Ti-1023 titanium alloys, prohibiting its large-scale engineering application. Therefore, to obtain high-quality LDED of Ti-1023 titanium alloy, this study used a regression analysis model to investigate the relationship between key process parameters and the geometrical characteristics of single clad tracks to obtain the forming process map. In addition, an off-axis high-speed camera was used to monitor the forming process of the Ti-1023 titanium alloy single clad tracks, and the correlation between the forming quality of the three types of forming conditions—namely incomplete melting, normal melting, and over-melting—and the characteristics of the molten pool was analyzed. Finally, this study established a simplified relationship between the process parameters, the molten pool characteristics, and fabrication quality of LDED of Ti-1023 titanium alloy, which is expected to improve development for the online monitoring and increase the application of LDED Ti-1023 titanium alloy.

Experimental investigation of novel powder bed friction stir process for AZ31B Mg alloy

The current work focused on the process response and mechanical properties variation of the AZ31B powder deposit made by an in-house developed process at a laboratory scale named Powder Bed Friction Stir (PBFS). The PBFS process employs friction stirring as a heating source instead of a laser or electron beam, as in powder bed fusion. Despite the tremendous effectiveness of Mg alloys for structural applications, a suitable route is still being searched for. The motivation of the current work is to explore the potential of the newly developed PBFS process for AZ31B Mg alloy deposition. With 1200rpm and 360 mm/min, the experimentation was carried out using the CPF tool to make a 7mm thick deposit on the AZ31B Mg plate. The process response and mechanical properties were studied to compare the result with wrought Mg alloy.

Atomic layer deposition of AlGaN alloy and its application in quantum dot sensitized solar cells

The role of plasma-enhanced atomic layer deposition growth of AlGaN ternary alloys on <i>c</i>-planar sapphire substrates and the preparation of quantum dot-sensitized solar cells are explored in this work. The interface between the film and the substrate as well as the band gap of AlGaN ternary alloys during atomic layer deposition is dependent on Al component. At high Al fraction, there appears a good interface between the AlGaN alloy film and the substrate, however, the interface becomes rough when the Al fraction is reduced. The AlGaN alloy prepared by atomic layer deposition has a high band gap, which is related to the oxygen content within the film. Subsequently, CdSe/AlGaN/ZnS and CdSe/ZnS/AlGaN structured cells are prepared and analyzed for quantum dot solar cells from AlGaN films with an AlN/GaN cycle ratio of 1∶1. It is found that AlGaN can modify and passivate quantum dots and TiO<sub>2</sub>, which can wrap and protect the structure of TiO<sub>2</sub> and CdSe quantum dot, thus avoiding the recombination of photo-generated carriers. This modification effect is also reflected in the improvement of open-circuit voltage, short-circuit current, filling factor and photovoltaic conversion efficiency of quantum dot solar cells. These factors are discussed in this work, trying to modify carrier transport characteristics of AlGaN films prepared by atomic layer deposition.

Repair of soft magnetic properties of wasted silicon steel and Co7Fe3 alloy deposition mechanism.

In order to repair the soft magnetic properties of wasted silicon steel, a theoretical process of co-depositing Co-Fe soft magnetic alloy on the surface of wasted silicon steel is proposed. The results show that the co-deposited Co-Fe alloy coatings can serve to repair the soft magnetic properties of wasted silicon as detected by the vibrating sample magnetometer, and the alloy coatings with Co7Fe3 as the main phase structure can provide surface protection for silicon steel. Subsequently, the mechanism of co-deposited Co-Fe alloys was investigated, and it was concluded that Co2+ and Fe2+ undergo a one-step two-electron co-deposition reaction, as studied using cyclic voltammetry. The chronoamperometric analysis and its fitting results indicated that the deposition of Co2+ and Fe2+ was a diffusion-controlled transient nucleation process, and the AC impedance indicated that higher voltages were favorable for the deposition of Co-Fe alloys but were accompanied by hydrogen precipitation reactions.

Electrodeposition Behavior of Zn-Ni Alloy from Alkaline Zincate Solutions Containing Various Brighteners and its Microstructure

The effect of brighteners on the deposition behavior of Zn–Ni alloys ant its microstructure was investigated. Zn–Ni alloys were electrodeposited on Cu electrode at 10–5000 A·m−2, 105 C·m−2, 308 K in unagitated zincate solutions containing various brighteners. Although the degree of suppression of hydrogen evolution was different depending on the kind of brightener, the transition current density at which the deposition behavior shifted from normal to anomalous was almost same in solutions containing brighteners. The current efficiency for alloy deposition significantly decreased with an addition of brighteners which had suppression effect on the Zn deposition. Since the brighteners more suppressed the Ni deposition than Zn deposition, the Ni content in deposited films decreased with an addition of brighteners. When the brightener of a straight-chain polymer composed of a quaternary ammonium cation (PQ) which can suppress the diffusion of ZnO22− and Ni ions in solution was added, the Ni content in deposited films increased with increasing current density at high current density region. This is attributed to that Zn which is preferentially deposited over Ni earlier reached the diffusion limitation of ZnO22− ions and Ni deposition didn’t reach the diffusion-limited current density. When both PQ and a quaternary ammonium salt with a benzene ring were added in solution, the films obtained at the diffusion-limited current density of ZnO22− ions exhibited the smooth surfaces composed of fine crystals. With an addition of brighteners to increase the overpotential for deposition, the γ-phase (intermetallic compound of Ni2Zn11) of the deposited films was formed easily.

Study the effect of adding zirconia particles to nickel–phosphorus electroless coatings as product innovation on stainless steel substrate

Abstract Scholars have spent much time studying metal deposition procedures involving the deposition of electroless nickel, alloy, and composite coatings on various surfaces; the most current uses were feasible advantages of the coatings’ many good properties for achieving the final product innovation. Lately, these coatings have demonstrated intriguing wear and corrosion resistance features, resulting in several innovative macro-level developments. The notion of composite coating by co-deposition coating has been presented in this article. The characteristics of Ni–Pb alloy coatings were examined by inserting ZrO 2 {{\rm{ZrO}}}_{2} particles into the electroless deposited solution. The stainless steel (SS) specimens have been electroless coated with Ni–Pb and ZrO 2 {{\rm{ZrO}}}_{2} nanoparticles (size = 30–70 nm) at 0, 10, and 20 g/L amounts. The materials have been examined using scanning electron microscope and atomic force microscope, followed by wear-resistant and microhardness testing. According to the investigation findings, including inert particles improved the hardness magnitude and wearing resistance considerably. The base metal exhibited the highest wear rate at 10 N, while the wear rate decreased in the Ni–Pb– ZrO 2 {{\rm{ZrO}}}_{2} -coated SS316L by 34%. The Vickers hardness magnitudes of the Ni–Pb– ZrO 2 {{\rm{ZrO}}}_{2} -coated samples at different ZrO 2 {{\rm{ZrO}}}_{2} contents (0, 10, and 20 g/L) were 19, 50, and 81%, respectively.

Mathematical prediction of melt pool geometry and temperature profile for direct energy deposition of 15Cr5Ni SS alloy

Mathematical prediction of melt pool geometry and temperature profile for direct energy deposition of 15Cr5Ni SS alloy