Tantalum Coatings: Applications, Techniques, and Properties

This study investigates the in vitro biocompatibility, corrosion resistance, and adhesion strength of a gas abrasive-treated Ti6Al4V alloy, alongside microplasma-sprayed titanium and tantalum coatings. Employing a novel approach in selecting microplasma spray parameters, this study successfully engineers coatings with tailored porosity, roughness, and over 20% porosity with pore sizes up to 200 μm, aiming to enhance bone in-growth and implant integration. This study introduces an innovative methodology for quantifying surface roughness using laser electron microscopy and scanning electron microscopy, facilitating detailed morphological analysis of both the substrate and coatings. Extensive evaluations, including tests for in vitro biocompatibility, corrosion resistance, and adhesive strength, revealed that all three materials are biocompatible, with tantalum coatings exhibiting superior cell proliferation and osteogenic differentiation, as well as the highest corrosion resistance. Titanium coatings followed closely, demonstrating favorable osteogenic properties and enhanced roughness, which is crucial for cell behavior and attachment. These coatings also displayed superior tensile adhesive strengths (27.6 ± 0.9 MPa for Ti and 28.0 ± 4.9 MPa for Ta), surpassing the ISO 13179-1 standard and indicating a robust bond with the substrate. Our findings offer significant advancements in biomaterials for medical implants, introducing microplasma spraying as a versatile tool for customizing implant coatings, particularly emphasizing the superior performance of tantalum coatings in terms of biocompatibility, osteogenic potential, and corrosion resistance. This suggests that tantalum coatings are a promising alternative for enhancing the performance of metal implants, especially in applications demanding high biocompatibility and corrosion resistance.

Laser cladding of a novel Fe-based coating with high wear resistance, corrosion resistance and self-lubricating properties

Tantalum is a promising orthopaedic implant coating material due to its robust mechanical properties, corrosion resistance, and excellent biocompatibility. Previous studies have demonstrated improved biocompatibility and tissue integration of surface-treated tantalum coatings compared to untreated tantalum. Surface modification of tantalum coatings with biologically inspired microscale and nanoscale features may be used to evoke optimal tissue responses. The goal of this study was to evaluate commercial tantalum coatings with nanoscale, sub-microscale, and microscale surface topographies for orthopaedic and dental applications using human bone marrow-derived mesenchymal stem cells (hBMSCs). Tantalum coatings with different microscale and nanoscale surface topographies were fabricated using a diffusion process or chemical vapor deposition. Biological evaluation of the tantalum coatings using hBMSCs showed that tantalum coatings promote cellular adhesion and growth. Furthermore, hBMSC adhesion to the tantalum coatings was dependent on surface feature characteristics, with enhanced cell adhesion on sub-micrometer- and micrometer-sized surface topographies compared to hybrid nano-/microstructures. Nanostructured and microstructured tantalum coatings should be further evaluated to optimize the surface coating features to promote osteogenesis and enhance osseointegration of tantalum-based orthopaedic implants.

In order to obtain the high wear- and corrosion-resistant nickel based alloy coatings for laser remanufacturing fretting damaged metal parts which are serviced under high-temperature corrosion and wear conditions, a novel NiCrSiFeBW–CeO2 alloy powder was designed by increasing the content of B and Si, adding tungsten and CeO2 using JMatpro software on the basis of Ni60 alloy powder composition, and the NiCrSiFeBW–CeO2 coating was successfully cladded on 45# steel under different laser energy area densities. The microstructure, wear and corrosion behaviors of the NiCrSiFeBW–CeO2 coatings were systematically studied. The results show that novel NiCrSiFeBW–CeO2 coating produced by laser cladding not only has no cracks but also has both high wear resistance and corrosion resistance due to some ultra-fine compound particle phases in situ generated in its structure. Among these phases, the B3Cr5, CrB4, (Cr, Ni)3C2, Cr7C3, W3Cr12Si5 and (Fe, Ni)5Si3 played a significant role in reinforcing the wear resistance of the coating, while the B3Cr5, W3Cr12Si5 and CrB4 enhanced the corrosion resistance of the coating. The novel NiCrSiFeBW–CeO2 coating prepared under 100 J/mm2 EAD has the best comprehensive performance, the wear loss is 7.53 × 10−5 mm3/N, the Ecorr is − 0.1738 V. Compared with Ni60 alloy coating, the novel Ni-based coating not only has a better laser cladded formability but also similar wear resistance and better corrosion-resistance. It provides a reference for repairing fretting damaged metal parts by laser cladding the nickel based coating with high wear and corrosion resistance.

Recently, tantalum has been attracting much attention for its anticorrosion resistance and biocompatibility, and it has been widely used in surface modification for implant applications. To improve its osteogenic differentiation of human bone marrow stem cells (hBMSCs), a micro/nano structure has been fabricated on the tantalum coating surface through the combination of anodic oxidation and plasma spraying method. The morphology, composition, and microstructure of the modified coating were comprehensively studied by employing scanning electron microscopy (SEM), X-ray diffraction (XRD) as well as transmission electron microscopy (TEM). The effects of hierarchical structures as well as micro-porous structure of tantalum coating on the behavior for human bone marrow stem cells (hBMSCs) were evaluated and compared at both cellular and molecular levels in vitro. The experimental results show that a hierarchical micro/nano structure with Ta2O5 nanotubes spread onto a micro-scale tantalum coating has been fabricated successfully, which is confirmed to promote cell adhesion and spreading. Besides, the hierarchical micro/nano tantalum coating can provide 1.5~2.1 times improvement in gene expression, compared with the micro-porous tantalum coating. It demonstrates that it can effectively enhance the proliferation and differentiation of hBMSCs in vitro.

Exploring the dual effect of sodium lignosulfonate-modified LDH treatment and heat processing on elevating corrosion and wear resistance of Ni-W composite coatings

Refractory high-entropy alloys: A focused review of preparation methods and properties

Research on the surface characterization, corrosion and bioactivity of nano-featured tantalum coating on selective electron beam melted Ti6Al4V alloy

Tantalum coated NiTi alloy by PIIID for biomedical application

Tungsten (W) and its alloys have been applied to various industrial fields for its excellent mechanical, tribological and chemical properties. Electrodeposition process is anticipated to be a economical and cost-effective method for preparing W-based alloys since W has the highest melting point among metals (3422 ℃). In general, electrodeposition of metal W from aqueous solution is difficult because it exists as oxyanions in a wide pH range. However, electrodeposition in the co-existence of iron group metals such as iron (Fe), nickel (Ni), and cobalt (Co), enables W to be reduced to metal state, which is so called the induced co-deposition. Recently, electrodeposited W alloys have gained increased attention due to their advanced properties such as high microhardness, thermal stability, wear resistance and corrosion resistance. Among them, binary Fe-W, Ni-W alloys have been most intensively studied. These alloys are expected to be promising substitute for hard chrome (Cr) plating due to its high hardness, abrasion resistance, heat resistance and corrosion resistance without the use of hazardous hexavalent chromium (Cr6+). Meanwhile, Ni has been reported as the one of the major elements in triggering skin allergies for humans. Therefore, we focused on Fe-W-based alloys that do not use Ni. Unfortunately, Fe-W alloys are reported to have inferior mechanical properties and corrosion resistance compared to Ni-W alloys. Thus, the addition of Zinc (Zn); an element that is widely used in anti-corrosion coatings, as a third element to the Fe-W binary alloy was considered for preparation of a ternary alloy with improved properties.This study reports the first experimental results of electrodeposition of ternary Fe-W-Zn alloy by incorporation of Zn to Fe-W alloys. Ternary Fe-W-Zn plating was prepared in citrate-ammonia aqueous solution heated to 80℃ by potentiostatic elcecrolysis range from -1.1 to -1.4V (vs. Ag/AgCl). Ternary alloys with the compositions of Fe-(28.8 to 37.1 at.%) W-(1.7 to 6.5 at.%) Zn were obtained with maximum current efficiency of 42%. The corrosion properties of the prepared ternary alloys were compared with those of Ni-W and Fe-W platings by a potentiodynamic polarization test in deaerated 1M sulfuric acid solution and 3 mass% sodium chloride solution. Although Zn has lower potential than Fe, ternary Fe-W-Zn alloys with relatively low Zn contents of 1.7 to 2.6 at.% showed better anti-corrosion properties than Ni-20 at.%W and Fe-33 at.%W alloys in acidic media. Addition of a small amount of Zn was found to be effective in tuning properties of Fe-W alloys. Acknowledgement This work was partially supported by the JST-OPERA Program, Japan [grant number JPMJOP1843]

Corrosion-wear behaviour of PVD Cr/CrN multilayer coatings for gear applications

Recent researches on Cu-Ni alloy matrix composites through electrodeposition and powder metallurgy methods: A review

Cobalt-based tungsten carbide composite (WC-Co, with different grades) is the commonly used material for cutting tools and tribological components, because of its high hardness and high wear and corrosion resistance. The carbon fiber-reinforced plastics (CFRP) and Al-SiC metal-matrix composites (MMCS) are materials mostly used in aerospace and automobile industries due to their high strength-to-weight ratio. During the machining of these composite materials, the conventional WC-Co cutting tools are subjected to high abrasive wear because they contain constituent hard reinforced particles. Thus, these types of machining applications need super-hard coatings for better performance and durability. Nowadays, synthetic diamond coatings obtained by chemical vapour deposition (CVD) process play an important role in improving the performance of the carbide tools while machining these composite materials, because of their superior mechanical and tribological properties. CVD diamond coatings with good wear resistance, super hardness, and low friction coefficient are in demand for industrial applications. But, the main problem of these diamond coatings is the coating de-lamination under high mechanical loads experienced during the machining process. Presently, researchers concentrate on the improvement of the coating adhesion for their better performance. However, to achieve the desired synthetic diamond coating for industrial applications many characteristics of the coating-substrate system need to be considered like good adhesion, optimum coating thickness, and minimum thermal residual stresses. Therefore, the microstructure and architecture of the synthetic diamond coatings should be adjusted to achieve the basic practical requirements like high wear resistance, high hardness, enough adhesion strength, and low friction coefficient.

Nickel–titanium alloy, with the features of shape memory effect, superelasticity and biocompatibility offers many unique advantages for the biomedical application. These applications have included everything from surgical tools to permanent implants [1–3]. However, many researchers highlighted the selective dissolution of Ni ion from the NiTi alloy during the corrosion process, which could lead to potential danger [4–6]. Different surface treatments have been investigated to improve the corrosion resistance of NiTi implants [7–10]. In modern medicines, to analyze the motion of implants, it is necessary to estimate the 3D position and orientation of each component using radiography [11]. When small stents, guidewires and catheter are quite thin and space farther apart, the detection of the implantable devices or tools become very difficult [12, 13]. The methods to enhance the visibility under X-ray include adding a mark of noble metals and coating with gold, etc. Although gold plating of nitinol components to improve the radiopacity has been achieved by means of electroplating technique, problems such as risks of galvanic corrosion, biocompatibility and hydrogen embrittlement still exist [14]. Tantalum metal has successfully been used for implants for half a century [15]. Since the galvanic potentials of tantalum and nitinol are very similar, the galvanic corrosion effect is almost immeasurable and complete failure of the implants is impossible [16]. Tantalum and tantalum oxide particles are often used to improve radiopacity of other materials [17, 18]. No problems have been reported concerning its biocompatibility [19–22]. It has been found that tantalum coatings are 100% pinhole-free and show great potential within both industrial and medical applications [23]. Tantalum coating with a very ductile nature is suitable where a product can be improved by combining material characteristics of the substrate with an exceptional corrosion-resistant surface [24, 25]. As a result, tantalum is an excellent candidate for usage as coatings for NiTi alloys to improve its anti-corrosion property and radiopacity. For coating applications, a good bonding strength between the coating and the substrate is required in order to ensure the lifetime service in the implanting environment [26]. The multi arc ion-plating technique, with the feature of high packing density and good adhesion, can satisfy this requirement [27]. Accordingly, the purpose of the present study is to develop a novel biocompatible and radiopaque Ta coating on NiTi alloy by multi-arc ion plating technique, the surface characterization, corrosion behavior and hemocompatibility are investigated. The chemical composition of the experimental alloy was Ti-50.6 at%. All samples were mechanically polished to 1 lm and then ultrasonically cleaned in acetone, alcohol and distilled water successively, then dried and loaded into the deposition chamber. The tantalum coatings were deposited by multi arc ion-plating technique [27]. Prior to deposition, the surfaces of the NiTi alloy substrates were further cleaned by Ar ion bombardment with energy of 1100 eV for 10 min. And the temperature of the NiTi alloy substrates was held to be 300 C. The substrate bias voltages were controlled to be )300 V with an arc current be 75 A, deposition pressure Y. Cheng AE Y. F. Zheng (&) Department of Materials and Nanotechnology, College of Engineering, Peking University, Beijing 100871, China e-mail: yfzheng@pku.edu.cn

The β to α phase transition of tantalum coatings deposited by modulated pulsed power magnetron sputtering