Surface Modification Technology Research Articles

Surface modification of biomedical titanium alloy for hard tissue repair and reconstruction

In biomedical applications, various materials are used, including metals and their alloys, polymers and ceramics. Among them, titanium (Ti) and titanium alloys are widely utilised in implant materials due to their excellent corrosion resistance and high mechanical strength. However, despite these advantages, titanium is biologically inert and does not integrate well with human cells. Therefore, surface modification of titanium implants plays a crucial role in determining the rate of osseointegration and the overall success of the implants. The primary objective of this review is to provide a detailed introduction to surface modification technologies for titanium alloy implants. The aim is to enhance the biological activity, wear resistance, corrosion resistance and antibacterial properties and reduce the release of ions from the implants. By modifying the surface of titanium implants, it is possible to create a more favourable environment for cell adhesion, proliferation and differentiation. Various techniques, such as physical methods (e.g. sandblasting, acid etching) and chemical methods (e.g. surface oxidation, plasma treatment) can be employed to modify the surface properties of titanium implants. These surface modification techniques can enhance the interaction between the implant and the surrounding biological environment, promoting osseointegration and improving the long-term stability of the implant. Additionally, surface modifications can help reduce the release of potentially harmful ions from the implant, minimise bacterial adhesion and improve the overall biocompatibility of the implant. In conclusion, surface modification of titanium alloy implants is a critical aspect of biomedical engineering. By improving the biocompatibility of titanium implants, these modifications contribute to the success and longevity of implants used in hard tissue repair and reconstruction.

Bionanocomposites preparation by design: Planning based on the modification of ceria nanoparticles by polydopamine interleaved with the chitosan biopolymer

Herein, the marine source polymer, chitosan (CS), was utilized to fabricate bionanocomposites by mussel-inspired sonochemical assisted method. The surface modified nanofillers as active ingredients were provided by assembling biomimetic polydopamine (PDA) onto the CeO2 nanoparticles through redox polymerization as a surface modification technology. Standard spectroscopic methods were used to characterize the resulting cerium oxide PDA-treated nanoparticles (NPs). CeO2/PDA/CS nanocomposites (NC)s were manufactured using a sonochemical process by inserting nanostructured fillers into the CS polymer matrix. The morphological features and structural characteristics of NCs were considered using field emission scanning electron microscopy, X-ray diffraction, Fourier transform infrared spectroscopy, transmission electron microscopy, and thermogravimetric analysis techniques. It was found that based on the biomimetic PDA layer the hydrogen bond interactions between CS biopolymer functional units with PDA functional units have occurred. Therefore, a pleasant distribution of surface adapted NPs in macromolecular matrix in the form of nanostructured composites was observed.

Grain refinement and Laves phase dispersion by high-intensity ultrasonic vibration in laser cladding of Inconel 718

Laser cladding is a promising surface modification and repair technology for fabricating Inconel 718 parts. However, laser cladding may produce coarse grains and brittle Laves phase, leading to a significant decrease in performance. The application of high-intensity ultrasonic vibration in laser cladding is able to refine grain and reduce Laves phase. This study investigates the distribution characteristics and the evolution mechanism of the grains and Laves phase in laser cladding with high-intensity ultrasonic vibration. The effects of high-intensity ultrasonic vibration on alteration of grain characteristics and the reduction of Laves phase were analyzed and discussed through ultrasonic vibration-assisted laser cladding experiments. Results indicate that high-intensity ultrasonic vibration promoted a columnar-to-equiaxed transition, and reduced the grain size from 75.6 μm to 48.8 μm. Furthermore, the Laves phase had a decrease of 47.1% in the volume fraction, and transformed from a long-striped shape into a fine granular shape, leading to a more homogeneous distribution of elements in Laves phase. The change in the grains and the Laves phase is attributed to dendrite fragmentation and inhibition of element segregation by nonlinear effects of ultrasound including cavitation and acoustic streaming. The findings of this study confirm the significant benefits of applying high-intensity ultrasonic vibration in laser cladding and provide insight into the underlying evolution mechanisms of high-intensity ultrasonic vibration for grains and Laves phase.

Cellulose acetate filter rods tuned by surface engineering modification for typical smoke components adsorption

Abstract A series of filter rods (FRs) with sodium alginate (SA) modification were prepared by a simple one-pot pre-treatment surface modification method for the retention of typical smoke components. The influences of SA on the physico-chemical properties and adsorption behaviors (or retention characteristics) toward FRs were investigated in detail. Based on the results of XRD, BET, and SEM, it can be inferred that SA modification has no influences on compositions and textural properties of FRs. However, surface modification of FR by SA can greatly improve the hydrophilicity of FR, which is crucial for water retention. In situ diffuse Fourier-transform infrared spectroscopy results demonstrate that FR modified by 2 g·L−1 SA presents superior adsorption character for acetone. The differences in the adsorption or retention of water and acetone are ascribed to surface enriched functional groups tuned by surface engineering modification. By contrast, the modification of SA had no obvious effect on the adsorption of CO at room temperature. By contrast, at high temperature, low modification concentration is conducive to the CO2 and CO adsorption. It presents a good perspective for the rational design of new filter materials to reduce the release of harmful components in cigarette smoke.

Molten salt-modified Ti3C2Tx MXene with tunable oxygen-functionalized surfaces for effective detection of NO2 at room temperature

The abundant tunable functional groups and room-temperature sensing properties of MXenes have garnered increasing interest in the field of gas sensing. However, the majority of research has exclusively focused on the combined impact of external substances with MXenes functional groups, with limited exploration into the modulation of MXenes’ intrinsic functional groups. In this work, we successfully produced molten salt-modified Ti3C2Tx MXene (M-Ti3C2Tx) with tunable oxygen-functionalized surfaces using the molten salt immersion method and employed it as a chemical resistive gas sensor to detect NO2 at room temperature (RT). Using diverse analytical techniques, we propose the O−addition effect on the surface titanium atoms and the O−substitution effect on the edge carbon atoms, refining the existence form of –O functional groups as well as realizing the effective regulation of the intrinsic functional groups. With a high response (∼25.87%−100 ppm NO2, whose response value is five times higher than that of pristine Ti3C2Tx), relatively rapid response speed (∼99 s−25 ppm NO2), high sensitivity (∼0.29 ppm−1), low detection limits (theoretical LoD is 3.3 ppm), good selectivity and long-term stability (maintain stable within 28 days) at RT, the sensor based on M-Ti3C2Tx demonstrates excellent NO2 sensing performance. To understand the sensing mechanism, density functional theory (DFT) calculations were conducted to explore adsorption behaviors. Theoretical analysis validates that M-Ti3C2Tx has a stronger adsorption capacity for NO2 (Ead = −1.149 eV) owing to the formation of covalent bond between the –O functional group and the nitrogen atom of NO2. The application of the molten salt can effectively modulate the intrinsic functional groups of MXenes, expanding the scope of MXenes surface modification engineering and creating new opportunities for enhancing the gas sensing capabilities of MXenes.

In-situ-growth of hard-coating, its impact on mechanical performances in cemented-carbides

This study focuses on preparing two types of cemented carbides: one with Ti elements and the other without, using a stepwise sintering process, primarily evaluating their mechanical properties. The research includes a thorough analysis of microstructure changes and post-wear surface alterations, coupled with assessments of phase composition, element content, relative density, surface hardness, fracture toughness, and wear properties. Results reveal that cemented carbides treated with in-situ surface modification under high-temperature nitrogen atmospheres exhibit exceptional densification. An in-situ hard-phases layer, predominantly TiN or Ti(C, N), is gradually grown on the surface of the WC-Co-Mo-TiNC cemented carbides, enhancing surface hardness and fracture toughness. This technology fortifies the material against indentation, crack expansion, and fracture, significantly improving wear resistance and extending service life. In essence, the in-situ surface modification technology, especially under high-temperature nitrogen atmospheres, emerges as a transformative approach, enhancing mechanical properties and substantially improving wear resistance for prolonged practical applications.

Experimental studies of hydrodynamics of the «plate» type canonical region with a modified surface

The possibility of using biomimetic approaches, in particular, the "lotus leaf" effect, expressed in the superhydrophobicity of streamlined surfaces, is considered. The results are presented of experimental studies of the influence produced by various modifications of the surface of the “plate” type canonical region on its hydraulic characteristics. The plates were streamlined in a hydrodynamic tray of rectangular cross-section. Copper plates with dimensions of 200x300x1 mm were studied. Three plates were considered, identical in geometry, but with different surface conditions — one in its original state; one with surfaces modified based on a surfactant; and one with surfaces treated by laser ablation (laser formation of a multimodal relief) with subsequent modification based on surfactants. In the course of experimental studies, the velocity distribution behind streamlined plates with different surface characteristics was obtained. Based on the nature of the velocity variations of the trail behind the streamlined plates, it is concluded that the amount of hydraulic resistance decreases due to surface modification. The weighted average velocity behind the streamlined plate increased by more than 4% for a plate with a combined modified surface compared to the original one. The process of a copper plate surface modifying using laser ablation, as well as the formation of additional surfactant molecular layers in order to achieve the maximum effect of superhydrophobicity is described. The most effective technological features of the laser ablation process are determined, such as the radiation power and frequency, the most preferred relief of modified surfaces and its geometric parameters. The most characteristic features of the influence of the surface roughness on the wetting angle (θ) are considered. With the OSA 20 complex, the wetting angles were determined for all the prepared plate samples. The research results prove the prospects of this surface modification technology for use in hydraulic machines.

Synergistic Amelioration of Osseointegration and Osteoimmunomodulation with a Microarc Oxidation-Treated Three-Dimensionally Printed Ti-24Nb-4Zr-8Sn Scaffold via Surface Activity and Low Elastic Modulus.

Biomaterial scaffolds, including bone substitutes, have evolved from being primarily a biologically passive structural element to one in which material properties such as surface topography and chemistry actively direct bone regeneration by influencing stem cells and the immune microenvironment. Ti-6Al-4V(Ti6Al4V) implants, with a significantly higher elastic modulus than human bone, may lead to stress shielding, necessitating improved stability at the bone-titanium alloy implant interface. Ti-24Nb-4Zr-8Sn (Ti2448), a low elastic modulus β-type titanium alloy devoid of potentially toxic elements, was utilized in this study. We employed 3D printing technology to fabricate a porous scaffold structure to further decrease the structural stiffness of the implant to approximate that of cancellous bone. Microarc oxidation (MAO) surface modification technology is then employed to create a microporous structure and a hydrophilic oxide ceramic layer on the surface and interior of the scaffold. In vitro studies demonstrated that MAO treatment enhances the proliferation, adhesion, and osteogenesis capabilities on the scaffold surface. The chemical composition of the MAO-Ti2448 oxide layer is found to enhance the transcription and expression of osteogenic genes in bone mesenchymal stem cells (BMSCs), potentially related to the enrichment of Nb2O5 and SnO2 in the oxide layer. The MAO-Ti2448 scaffold, with its synergistic surface activity and low stiffness, significantly activates the anti-inflammatory macrophage phenotype, creating an immune microenvironment that promotes the osteogenic differentiation of BMSCs. In vivo experiments in a rabbit model demonstrated a significant improvement in the quantity and quality of the newly formed bone trabeculae within the scaffold under the contact osteogenesis pattern with a matched elastic modulus. These trabeculae exhibit robust connections to the external structure of the scaffold, accelerating the formation of an interlocking structure between the bone and implant and providing higher implantation stability. These findings suggest that the MAO-Ti2448 scaffold has significant potential as a bone defect repair material by regulating osteoimmunomodulation and osteogenesis to enhance osseointegration. This study demonstrates an optional strategy that combines the mechanism of reducing the elastic modulus with surface modification treatment, thereby extending the application scope of β-type titanium alloy.

Numerical investigation on pool boiling heat transfer with trapezoidal/inverted trapezoidal micro-pillars using LBM

Pool boiling with high-efficient heat transfer process is crucial to chemical engineering, nuclear engineering, electronic cooling, and other energy conversion applications. Surface modification technology has attracted more attention in recent years as a simple and reliable boiling enhancement technique. Most of the studies using surface modification technology have focused on the enhancement effect of rectangular micro-structures, only a few researchers have adequately investigated the enhancement effects on pool boiling heat transfer and mechanisms of other complex micro-structures (like circle, trapezoid, or inverted trapezoid). In the present study, the pool boiling processes on surfaces with trapezoidal/inverted trapezoidal micro-pillars were numerically investigated using lattice Boltzmann method (LBM). The bubble dynamics and heat transfer characteristics during the pool boiling processes on surfaces with different pillar bottom angles (30° ≤ θ ≤ 135°) were compared under different wall-superheat conditions. The orthogonal tests were adopted on micro-pillars to optimize the geometric parameters, including the bottom angle of the micro-pillar, the bottom width of the micro-pillar, the number of the micro-pillar, and the height of the micro-pillar. A new CHF correlation on the mixed wettability surface with trapezoidal/inverted trapezoidal micro-pillars was proposed. It can be found that the main mechanism of nucleate boiling heat transfer on the micro-pillars is the evaporation of the microlayer, and the pillar bottom angle reveals a remarkable effect on the pool boiling performance on the mixed wettability surfaces. The surface of θ = 135° has the minimum wall-superheat at the onset of nucleate boiling (ONB). Within a wide range of wall-superheat conditions, the heat transfer efficiency of pool boiling firstly increases with the increasing of the bottom angle of the micro-pillar and subsequently decreases. The surface of θ = 60° has the highest critical heat flux (CHF). The surface of θ = 90° has the highest heat transfer efficiency in the film boiling process. The results of orthogonal tests suggested that the bottom angle of the micro-pillar is the most significant influential factor, and the optimal geometrical combinations were proposed. The new CHF correlation has acceptable accuracy in predicting the CHF on surfaces with trapezoidal/inverted trapezoidal pillars, which provides guidance for the design and optimization of micro-structured surface modification in various pool boiling applications.

Influence of surface micro-oxidation on the formability of pure copper powders by selective laser melting

The absorption of laser energy by pure copper powders has a huge impact on the formation of high quality pure copper parts by selective laser melting. In this paper, surface modification technology was used to treat pure copper powder to improve the laser absorption effect of pure copper powder. It was found that modifying the surface of pure copper powder to generate a layer of CuO film effectively improved the absorption of laser energy by pure copper powder. Uniform and dense CuO films improved the quality of selective laser melting pure copper parts, which solved the problem of preparing pure copper powders for selective laser melting of high-density parts. The microstructure of selective laser melting high-density pure copper parts consisted of fine columnar and cellular crystals. The presence of subcrystals and dislocations was found in localized areas. The results of the physical phase analysis showed that the CuO phase existed in the parts prepared from the surface-modified pure copper powder, and the presence of the nano-CuO phase also enhanced, which effectively improved the microstructure and properties of the constituent selective laser melting pure copper parts.

Innovative Developments in Lumbar Interbody Cage Materials and Design: A Comprehensive Narrative Review.

This narrative review comprehensively examines the evolution and current state of the interbody cage technology for lumbar interbody fusion (LIF). This review highlights the biomechanical and clinical implications of transition from traditional static cage designs to advanced expandable variants for spinal surgery. The review begins by exploring the early developments in cage materials, highlighting the roles of titanium and polyetheretherketone in advancing LIF techniques. It discusses the strengths and limitations of these materials, leading to innovations in surface modifications and the introduction of novel materials, such as tantalum, as an alternative material. Advancements in three-dimensional printing and surface modification technologies form a significant part of this review, emphasizing the role of these technologies in enhancing the biomechanical compatibility and osseointegration of interbody cages. This review also explores the rise of biodegradable and composite materials such as polylactic acid and polycaprolactone, addressing their potential to mitigate long-term implant-related complications. A critical evaluation of static and expandable cages is presented in this review, including their respective clinical and radiological outcomes. While static cages have been a mainstay of LIF, expandable cages are noted for their ability to adapt to the patient's anatomy, potentially reducing complications such as cage subsidence. However, this review highlights the ongoing debate and the lack of conclusive evidence regarding the superiority of either cage type in terms of clinical outcomes. Finally, this review proposes future directions for cage technology, focusing on the integration of bioactive substances and multifunctional coatings and development of patient-specific implants. These advancements aim to further enhance the efficacy, safety, and personalized approach of spinal fusion surgeries. This review offers a nuanced understanding of the evolving landscape of cage technology in LIF and provides insights into the current practices and future possibilities in spinal surgery.

CATHODIC PLASMA ELECTROLYTIC DEPOSITION (CPED) TECHNIQUE FOR SURFACE STRENGTHENING OF TITANIUM AND TITANIUM ALLOYS: A MINI REVIEW

Due to the unique properties of titanium (Ti) and its alloys, it has a particularly wide range of applications in aerospace, automotive, medical and other fields. However, the problems of low surface hardness, high friction coefficient and low wear resistance of Ti alloys limit its development to a certain extent. The destruction of Ti and its alloys often occurs on the surface of materials such as wear damage, corrosion, and oxidation resistance. Therefore, the exploration and application of surface strengthening technology is particularly important. The cathodic plasma electrolytic deposition (CPED) technology, as a surface modification technology, can achieve better adhesion and facilitate the material to achieve better comprehensive performance. This paper briefly introduces the basic concepts, principles and development progress of CPED. Starting from the preparation of ceramic coatings, metal coatings, diamond-like carbon films and composite coatings, it summarizes the application of CPED in Ti and its alloys. Applications in alloys to improve thermal oxidation resistance, wear resistance, corrosion resistance, and film-based adhesion. At the end, its development in the new era environment is prospected.

BaSO4-Epoxy Resin Composite Film for Efficient Daytime Radiative Cooling.

Conventional cooling methods are based on active cooling technology by air conditioning, which consumes a large amount of energy and emits greenhouse gases. Radiative cooling is a novel promising passive cooling technology that uses external space as the cooling source and requires no additional energy consumption. Herein, we propose an approach to prepare highly dispersed BaSO4 nanoparticles (NPs) using a direct precipitation method combined with the in situ surface modification technology. The as-prepared PVP-modified BaSO4 NPs with an average size of 20 nm can be stably dispersed in ethanol for more than 6 months and then were used as building blocks to prepare spherical BaSO4 clusters with an average size of 0.9 μm using a scalable spray drying technique. The BaSO4 NPs/clusters (mass ratio 1:1) were used for preparing radiative cooling epoxy resin film, showing a high solar reflectance of 71% and a high sky window emissivity of 0.94. More importantly, this composite film displays superior radiative cooling performance, which can reduce the ambient temperature by 13.5 °C for the indoor test and 7 °C for the outdoor test. Compared with the commercial BaSO4 filled film, our BaSO4-epoxy resin composite film offers advantages not only in radiative cooling but also in mechanical properties with a 16.6% increase of tensile strength and 40.1% increase of elongation at break, demonstrating its great application potential in the field of building air conditioning.

Research Progress of Aluminum Alloy Welding/Plastic Deformation Composite Forming Technology in Achieving High-Strength Joints.

Fusion welding causes joint deterioration when joining aluminum alloys, which limits the use of aluminum alloy components in high-end equipment. This paper focuses on an overview of how to achieve high-strength aluminum alloy welded joints using welding/plastic deformation composite forming technology. The current technology is summarized into two categories: plastic deformation welding and plastic deformation strengthening. Plastic deformation welding includes friction stir welding, friction welding, diffusion welding, superplastic solid-state welding, explosive welding, and electromagnetic pulse welding. Plastic deformation strengthening refers to the application of plastic deformation to the weld seam or heat-affected zone, or even the whole joint, after welding or during welding, including physical surface modification and large-scale plastic deformation technology. Important processing parameters of plastic deformation welding and their effects on weld quality are discussed, and the microstructure is described. The effect of plastic deformation strengthening technology on the microstructure and performance evolution, including the hardness, tensile strength, fatigue property, residual stress, and hot cracking of aluminum alloy welded joints, and its evolution mechanism are systematically analyzed. Finally, this paper discusses the future development of plastic deformation strengthening technology and anticipates growing interest in this research area.

Study on the effect of different electrode forms on the surface modification of Ti–6Al–4V alloy by near-dry electrical discharge machining

The surface modification of Ti–6Al–4V alloy was achieved by using an electrical discharge machining (EDM) surface modification technology under the action of pulsed discharge to induce an in-situ synthesis reaction between the molten metallic material and the ionized elements in the atomized medium. In this study, nitrogen and urea solutions are used as the gas-liquid phases of the atomization medium. ANSYS simulation software was used to simulate and analyze the interpolar pressure and flow field of the different electrodes. The effect of different electrode forms on the EDM surface modification layer was investigated by designing comparative trials. Scanning electron microscopy (SEM), X-ray diffraction (XRD), and other detection methods were used to characterize the process indicators, such as surface morphology, roughness, hardness, and wear resistance of the reinforced layer. It was found that a thick and uniform continuous layer can be obtained on the Ti–6Al–4V alloy substrate using multi-channel electrode machining, and the thickness is about 65 μm. XRD analysis indicates that the reinforced layer mainly contains TiN, Ti2N, Ti2AlN, Ti2O, and CuO phases. The samples with reinforced layers were shown to have higher hardness (1578 HV) and better wear resistance than the titanium substrates. The main wear mechanism is spalling wear and light oxidation wear.

A Novel Tooth Modification Methodology for Improving the Load-Bearing Capacity of Non-Orthogonal Helical Face Gears

This study proposes a double-crown tooth surface modification technology that improves the load-carrying capacity of non-orthogonal helical tooth surface gears. The tooth modification is determined by a modified rack-cutter, and its feed motion is related to an intentionally designed transmission error. The novelty of the tooth modification design is that the transmission error can be pre-designed. First, changing the tooth profile of the tool enables preliminary modification along the tooth profile direction; second, by modifying the interaction between the tool and the machined gear, subsequent fine adjustments are made to the contact path. This two-stage tooth modification strategy not only retains the advantages of the traditional method but also significantly improves the balance of the load distribution on the tooth surface through an original contact path modification strategy. Through systematic tooth contact analysis (TCA) and loaded tooth contact analysis (LTCA), it was verified that the new method reduces contact stress and tooth root bending stress and improves the gear’s resistance to misalignment errors. This research provides the basis and motivation for further exploring and improving this tooth profile modification technology to solve the challenges faced by more complex gear systems.

Effects of different scanning speeds on microstructure evolution and tribological properties of Inconel 718 alloy vacuum electron beam surface modification

In this paper, based on vacuum electron beam surface modification technology, the surface modification experiments of electron beams on Inconel718 plates at different scanning speeds (180 mm/min, 240 mm/min, 300 mm/min, 360 mm/min and 420 mm/min) were studied. The microstructure evolution law and friction and wear properties of electron back scatter diffraction (EBSD) and friction and wear testing machine RTEC (MFT-5000) were analyzed. Then, SEM and EDS were used to study the friction and wear mechanism. The results show that the microstructure of Inconel 718 sample after electron beam surface treatment is divided into basis material (BM), central zone (CTZ) and column zone (CLZ). The grains in the BM region are equiaxial, the grains in the CTZ region are fine strips, and the CLZ region is dominated by short coarse grains. After electron beam treatment, the annealed twins inside the specimen are eliminated, and when the scanning speed is 300 mm/min, the recrystallization ratio is the largest and the orientation difference becomes the most uniform. Different recrystallization textures appeared in different scanning speed specimens, and the textures in the original state are concentrated on copper{112}<111> and S{123}<634 > textures. After electron beam treatment, the texture of the specimen is mainly concentrated in the cubic texture. Experiments have shown that electron beam surface treatment can reduce oxidative wear and adhesive wear of specimens. When the scanning speed is 300 mm/min, the wear volume is the smallest, the wear resistance is the best, and the wear rate is reduced by about 15 % compared with the original specimen. Electrochemical corrosion experiments demonstrated that the relative corrosion rate of Inconel 718 was 1.3 times higher than that of the selected electron beam clad specimens.

Review on wear resistance of laser cladding high-entropy alloy coatings

The wear resistance of the part surface has become an important factor affecting its own service life. Laser cladding (LC), as a surface modification technology, can prepare a coating with good metallurgical bonding with the substrate, which can significantly improve the wear resistance of the material surface. High entropy alloys (HEAs) are an emerging coating material with excellent wear resistance. Therefore, this paper reviews the latest development status in wear resistance of laser cladding-high-entropy alloy coatings (LC-HEACs) in terms of the HEAs material system, LC process parameters, strengthening phase, amorphous phase strengthening, assisted cladding, and post-treatment. At the same time, this paper also expounds on the mechanism of LC-HEACs enhancing the surface wear resistance of materials, and the current research status of LC-HEACs in different engineering materials and application environments. Finally, the current research deficiencies, challenges, and future development trends of LC-HEACs in the field of wear resistance are also elaborated, and it is expected to provide some references for their future development and applications.

Life cycle comprehensive performance assessment of the TiAlN coated tool based on surface treatment

The optimal surface treatment process can availably improve tool surface properties, and meet the requirements of low-carbon manufacturing. In this work, based on tool surface modification technology and tool life cycle carbon emission system, TiAlN coated tools are carried out micro-blasting treatment (MBT), cryogenic treatment (CT) and heat treatment (HT). The effects of surface treatment processes on the surface integrity (morphology, roughness, micro-hardness, residual stress) of the coated tool are studied. The high-speed dry finishing turning experiments of cobalt-based superalloy are carried out to investigate the tool wear morphology and wear mechanism. The carbon emissions of the tool life cycle are analyzed. Finally, the comprehensive performance of the coated tool within life cycle is evaluated. The results show that the highest level of surface integrity of coated tool is achieved by MBT, while the lowest carbon emission of environmental is impacted by HT. Compared with the untreated (UT) tool, the micro-blasted tool has the most significant improvement in surface roughness with a 28.6% reduction. The cryogenic treated tool has the greatest improvement on the surface hardness which is increased by 44.4%. The effect of HT on the surface residual stress is the most obvious. The surface stress of the heat-treated tool has increased by 59.4%. Moreover, the flank wear VB of the micro-blasted tool, cryogenic treated tool and heat-treated tool is reduced by 25.17%, 24.50% and 32.12%, respectively. The main wear mechanisms of the treated tool are adhesive wear, oxidation wear and abrasive wear. According to comprehensive performance assessment, the performance of surface treatment process during the coated tool life cycle is: HT > MBT > CT > UT.

Rapid Batch Surface Modification of 3D-Printed High-Strength Polymer Scaffolds for Enhanced Bone Regeneration In Vitro and In Vivo

In the emergency treatment of acute injuries in orthopedics, 3D-printing technology shows great promise due to its ability to rapidly and mass production of implants with complex structures. However, further surface modification on 3D-printed implants can often be complicated and time-consuming, leading to a prolonged timeframe from manufacturing to implantation. Therefore, there is an urgent need for rapid batch surface modification technology that can be effectively integrated with 3D-printing technology within the field of orthopedics. In this study, air-plasma treatment was used to rapidly modify 3D-printed polyetherimide (PEI) porous scaffolds and compared it with sulfonation treatment. Both methods achieved rapid surface modification of complex porous scaffolds in seconds to minutes (10 minutes), helping establish a cell-friendly surface morphology that encourages osteogenesis. Some new functional groups such as -OH and -SO3H were also introduced to promote osteogenesis. Interestingly, the air-plasma treated group enhanced cell adhesion, as indicated by a 1.6-fold increase in the number of cells compared to the control group. While sulfonation treatment accelerated the osteogenesis process, evidenced by a 1.7-fold increase in the number of calcium nodules in the sulfonation treated group compared to the control group in 7 days. To combine the advantages of air-plasma treatment and sulfonation treatment, the biological properties of their combined application were studied in vitro and in vivo for the first time. It was surprising to find that the combined application actually decreased the biological property of the material, which was associated with the generation of new free radicals. The results of this study will hopefully be applied to the rapid batch surface modification in 3D-printed porous implants to enhance their biological activity and improve the efficiency from manufacturing to implantation.