Influence of laser parameters on the microstructures and surface properties in laser surface modification of biomedical magnesium alloys

Biodegradable implants from magnesium(Mg)alloys have emerged in the biomedical field especially in the orthopedic and cardiovascular stent applications owing to their low density,high specific strength,excellent machinability,good biocompatibility,and biodegradability.The primary shortcoming of Mg-based implants is their low corrosion resistance in the physiological environment,which results in premature mechanical integrity loss before adequate healing and the production of excessive hydrogen gas,which is harmful to the body tissues and negatively affects the biocompatibility of the implant.Laser surface modification has recently received attention because it can improve the surface properties such as surface chemistry,roughness,topography,corrosion resistance,wear resistance,hydrophilicity,and thus cell response to the surface of the material.The composition and microstructures including textures and phases of laser-treated surfaces depend largely on the laser processing parameters(input laser power,laser scan velocity,frequency,pulse duration,pressure,gas circulation,working time,spot size,beam focal position,and laser track overlap)and the thermophysical properties of the substrate(solubility,melting point,and boiling point).This review investigates the impacts of various laser surface modification techniques including laser surface melting,laser surface alloying,laser cladding,laser surface texturing,and laser shock peening,and highlights their significance in improving the surface properties of biodegradable Mg alloys for implant applications.Additionally,we explore how different laser process parameters affect its composition,microstructure,and surface properties in each laser surface modification technique.

Impact of scandium and terbium on the mechanical properties,corrosion behavior,and biocompatibility of biodegradable Mg-Zn-Zr-Mn alloys

Magnesium(Mg)-based bone implants degrade rapidly in the physiological environment of the human body which affects their structural integrity and biocompatibility before adequate bone repair.Rare earth elements(REEs)have demonstrated their effectiveness in tailoring the corrosion and mechanical behavior of Mg alloys.This study methodically investigated the impacts of scandium(Sc)and terbium(Tb)in tailoring the corrosion resistance,mechanical properties,and biocompatibility of Mg–0.5Zn–0.35Zr–0.15Mn(MZZM)alloys fabricated via casting and hot extrusion.Results indicate that addition of Sc and Tb improved the strength of MZZM alloys via grain size reduction and solid solution strengthening mechanisms.The extruded MZZM–(1–2)Sc–(1–2)Tb(wt.%)alloys exhibit compressive strengths within the range of 336–405 MPa,surpassing the minimum required strength of 200 MPa for bone implants by a significant margin.Potentiodynamic polarization tests revealed low corrosion rates of as–cast MZZM(0.25 mm/y),MZZM–2Tb(0.45 mm/y),MZZM–1Sc–1Tb(0.18 mm/y),and MZZM–1Sc–2Tb(0.64 mm/y),and extruded MZZM(0.17 mm/y),MZZM–1Sc(0.15 mm/y),MZZM-2Sc(0.45 mm/y),MZZM-1Tb(0.17 mm/y),MZZM-2Tb(0.10 mm/y),MZZM–1Sc-1Tb(0.14 mm/y),MZZM-1Sc-2Tb(0.40 mm/y),and MZZM–2Sc–2Tb(0.51 mm/y)alloys,which were found lower compared to corrosion rate of high-purity Mg(~1.0 mm/y)reported in the literature.Furthermore,addition of Sc,or Tb,or Sc and Tb to MZZM alloys did not adversely affect the viability of SaOS2 cells,but enhanced their initial cell attachment,proliferation,and spreading shown via polygonal shapes and filipodia.This study emphasizes the benefits of incorporating Sc and Tb elements in MZZM alloys,as they effectively enhance corrosion resistance,mechanical properties,and biocompatibility simultaneously.

Microstructures, mechanical properties, corrosion, and biocompatibility of extruded Mg-Zr-Sr-Ho alloys for biodegradable implant applications

In this study,the microstructures,mechanical properties,corrosion behaviors,and biocompatibility of extruded magnesium-zirconiumstrontium-holmium(Mg-Zr-Sr-Ho)alloys were comprehensively investigated.The effect of different concentrations of Ho on the microstructural characteristics,tensile and compressive properties,corrosion resistance,and biocompatibility were investigated.The microstructures of the extruded Mg-1Zr-0.5Sr-xHo(x=0.5,1.5,and 4 wt.%)alloys consisted ofα-Mg matrix,fineα-Zr particles,and intermetallic phase particles of Mg_(17)Sr_(2) and Ho_(2)Mg mainly distributed at the grain boundaries.Extensive{1012}tensile twins were observed in the partially recrystallized samples of Mg-1Zr-0.5Sr-0.5Ho and Mg-1Zr-0.5Sr-1.5Ho.Further addition of Ho to 4 wt.%resulted in a complete recrystallization due to activation of the particle stimulated nucleation around the Mg_(17)Sr_(2) particles.The evolution of a rare earth(RE)texture was observed with the Ho addition,which resulted in the weakened basal and prismatic textures.Furthermore,a drastic increase of 200%in tensile elongation and 89%in compressive strain was observed with Ho addition increased from 0.5 to 4 wt%,respectively.The tension-compression yield asymmetry was significantly decreased from 0.62 for Mg-1Zr-0.5Sr-0.5Ho to 0.98 for Mg-1Zr-0.5Sr-4Ho due to the weakening of textures.Corrosion analysis of the extruded Mg-Zr-Sr-Ho alloys revealed the presence of pitting corrosion.A minimum corrosion rate of 4.98 mm y^(−1) was observed in Mg-1Zr-0.5Sr-0.5Ho alloy.The enhanced corrosion resistance is observed due to the presence of Ho_(2)O_(3) in the surface film which reduced galvanic effect.The formation of a stabilized surface film due to the Ho_(2)O_(3) was confirmed through the electrical impedance spectroscopy and XPS analysis.An in vitro cytotoxicity assessment revealed good biocompatibility and cell adhesion in relation to SaOS2 cells.

Advances in Mg-Al-layered double hydroxide steam coatings on Mg alloys:A review

Layered double hydroxide(LDH)coatings on magnesium(Mg)alloys shine brightly in the field of corrosion protection because of their special ion-exchange function.State-of-the-art steam coating as a type of LDH film preparation technique has emerged in recent years because only pure water is required as the steam source and its environmentally friendly LDH coating fits the current need for green development.Moreover,this coating can effectively inhibit the corrosion of the Mg alloy substrate due to the chemical bonding between the coating and the Mg alloy substrate.This review systematically explains cutting-edge advancements in the growth mechanism and corrosion behavior of LDH steam coatings,and analyzes the advantages and limitations of the steam-coating method.The influencing factors including pressure,CO_(2)/CO_(3)^(2-),aluminum content of the substrate alloy,solution type,and acid-pickling pretreatment,as well as the post-treatment of steam-coating defects,are comprehensively elucidated,providing new insights into the development of the in situ steam-coating technique.Finally,existing issues and future prospects are discussed to further accelerate the widespread application of Mg alloys.

Improvements in mechanical, corrosion, and biocompatibility properties of Mg–Zr–Sr–Dy alloys via extrusion for biodegradable implant applications

In this study,extrusion was performed on Mg-Zr-Sr-Dy alloys for improving their mechanical,corrosion,and biocompatibility properties.Effects of extrusion and alloying elements on the microstructural characteristics,tensile and compressive strengths,corrosion behavior,and biocompatibility were investigated.The Mg-Zr-Sr-Dy alloys were composed of an α-Mg matrix containing {10■2} extension twins and secondary phases of intermetallic compounds Mg_(17)Sr_(2) and Mg_(2)Dy.Evolution of basal and rare earth(RE) textures was observed in the extruded alloys and an increase in Dy content to 2 wt.% resulted in texture randomization and strengthening of the RE component,mainly due to particle-stimulated nucleation and a change from discontinuous dynamic recrystallization to continuous dynamic recrystallization,which also led to an improved tension-compression yield asymmetry of 0.87.Extrusion of the alloys significantly enhanced their tensile and compressive properties due to improved distribution of alloying elements and formation of textures.Corrosion rates tested by hydrogen evolution testing,potentiodynamic polarization,and electrical impedance spectroscopy showed similar trends for each composition,and the lowest corrosion rate of 3.37 mmy^(-1) was observed for the Mg-1Zr-0.5Sr-1Dy in the potentiodynamic polarization testing.Dy_(2)O_(3) was observed in the inner layers of the Mg(OH)_(2) protective films,whose protective efficacy was confirmed by charge-transfer and film resistances.A comparison among the minimum CRs observed in this study and previously studied as-cast Mg-Zr-Sr-Dy and extruded Mg-Zr-Sr alloys,demonstrates that both the extrusion process and addition of Dy in Mg-Zr-Sr improved the CR.Similarly,extruded Mg-Zr-Sr-Dy alloys showed improved cell viability and adhesion of human osteoblast-like SaOS2 cells due to increased corrosion resistance and enhanced Sr distribution within the Mg matrix.

锂离子电池硅负极初始库仑效率的研究进展

硅被认为是最有前景的锂离子负极材料之一,具有比容量高,电位平台低,储量丰富等优势,但初始库仑效率低等问题限制了其在锂离子电池中的应用。为此,本文通过文献调研研究了初始库伦效率偏低的内在机理,着重从包覆、预锂化、纳米化、电解液改性等技术综述提高硅负极材料的初始库仑效率的方法并对未来发展趋势做了简单的展望。

锂离子电池硅基负极材料预锂化技术的研究进展

硅基负极材料由于具有比容量高、安全及商业发展前景好等优点而受到业界广泛关注,但锂离子电池硅基负极存在循环寿命短和首次库仑效率低等问题,采用硅基负极预锂化技术可有效改善这类问题。综述硅基负极材料预锂化技术的最新研究进展,着重阐述稳定的金属锂粉末、电化学预锂化、添加剂预锂化及机械预锂化等技术,并展望未来硅基负极预锂化的研究方向。

HA coating on Mg alloys for biomedical applications:A review

Magnesium(Mg)alloys are receiving increasing attention as biodegradable implant materials in recent years.However,their low corrosion resistance and fast degradation in the physiological environment remain challenges for a widespread application.Hydroxyapatite(HA)coating on Mg alloys can enhance their corrosion resistance,biocompatibility,and bioactivity of the Mg alloy substrates since the compositions of HA are similar to those of the hard tissue of natural bone.This review analyzes the challenges of Mg alloys for biomedical applications,the fundamental requirements for biodegradable metals,and the corrosion mechanisms of Mg alloys in the physiological environment.The benefits of HA coatings on Mg alloys,the most commonly used surface coating techniques and their advantages and limitations,and the in vitro and in vivo performance of Mg alloys with and without surface coatings are comprehensively elucidated.Multistep processes such as alkali treatment and then HA coating by electrochemical deposition on Mg alloys appear to be necessary to achieve a satisfactory surface coating on Mg alloys,which has been demonstrated to have the potential to improve the degrading behavior,bioactivity and biocompatibility.Multifunctional coatings are most effective in achieving safe and bioactive Mg alloy surfaces for promising biodegradable implant applications.

Graphene nanoplatelets-reinforced magnesium metal matrix nanocomposites with superior mechanical and corrosion performance for biomedical applications

Magnesium(Mg)metal matrix composites(MMCs)reinforced with graphene nanoplatelets(GNPs)have been developed by powder metallurgy(PM).GNPs with different concentrations(0.1,0.2,and 0.3 wt.%),layer thicknesses(5 nm and 9 nm),and particle sizes(15μm and 5μm)were dispersed into Mg powder by high-energy ball-milling processes.The microstructure and mechanical properties of the fabricated composites were characterized using transmission electron microscopy(TEM),scanning electron microscopy(SEM),energy dispersive X-ray spectroscopy(EDX),X-ray diffraction(XRD),Raman spectroscopy(RS),and compression tests.The corrosion resistance was evaluated by electrochemical tests and hydrogen evolution measurements.The cytotoxicity of Mg-GNPs composites was assessed using osteoblast-like SaOS2 cells.The results indicate that GNPs are excellent candidates as reinforcements in Mg matrices for the manufacture of biodegradable Mg-based composite implants.GNP addition improved the mechanical properties of Mg via synergetic strengthening modes.Moreover,retaining the structural integrity of GNPs during processing improved the ductility,compressive strength,and corrosion resistance of the Mg-GNP composites.Cytotoxicity assessments did not reveal any significant toxicity with the addition of GNPs to Mg matrices.This study demonstrates that Mg-xGNPs with x<0.3 wt.%,may constitute novel biodegradable implant materials for load-bearing applications.

Nano-tribological behavior of graphene nanoplatelet-reinforced magnesium matrix nanocomposites

The corrosion resistance and wear resistance of metallic biomaterials are critically important for orthopedic hard-tissue replacement applications because the lack of such properties not only adversely affects their mechanical integrity but also allows the release of wear debris into the human body.In this study,the potential of zirconium(Zr)as an alloying element and graphene nanoplatelets(GNPs)as a nano-reinforcement material were investigated in relation to improving the tribological performance of pure magnesium(Mg).The GNPs-reinforced Mg matrix nanocomposites(MNCs)were fabricated using powder metallurgy.Results indicate that additions of 0.5 wt.%Zr and0.1 wt.%GNPs to Mg matrices significantly improved the wear resistance by 89%and 92%at 200μN load,60%and 80%at 100μN load,and 94%and 93%at 50μN load,respectively,as compared to the wear resistance of pure Mg.The wear depth and coefficient of friction of the MNC containing 0.5 wt.%Zr and 0.1 wt.%GNPs(Mg0.5 Zr0.1 GNPs MNC)were considerably reduced as compared to pure Mg and Mg0.5 Zr.Our results demonstrate that the Mg0.5 Zr0.1 GNPs MNC is promising for orthopedic applications in relation to its excellent tribological performance.

Improvement on electrochemical performances of nanoporous titania as anode of lithium-ion batteries through annealing of pure titanium foils

The effect of annealing of Ti foils before anodization on the morphology and electrochemical performance of resultant nanoporous anatase TiO2 （np-TiO2） as anode in rechargeable lithium-ion batteries （LIBs） was investigated. The np-TiO2 anode fabricated from annealed Ti foils exhibited higher specific surface area and reduced pore diameter compared to np-TiO2 electrode fabricated from as-received Ti foils. The highly porous np-TiO2 anode fabricated from annealed Ti foils exhibited 1st discharge capacity of 453.25 mAh/g and reduced to 172.70 mAh/g at 1 C current rate after 300 cycles; whilst the np-TiO2 electrode fabricated from the as-received Ti foils exhibited 1st discharge capacity of 213.30 mAh/g and reduced to 160.0 mAh/g at 1 C current rate after 300cycles. Even after 400cycles, such np-TiO2 electrode exhibited a reversible capacity of 125.0 mAh/g at 2.5 C current rate. Compared to the untreated Ti foils, the enhanced electro- chemical performance of np-TiO2 anode fabricated from annealed Ti foils was ascribed to the annealing- induced removal of residual stress among the Ti atoms. The benefit of annealing process can reduce pore size of as-fabricated np-TiO2.

Mechanical and corrosion properties of graphene nanoplatelet–reinforced Mg–Zr and Mg–Zr–Zn matrix nanocomposites for biomedical applications

Magnesium(Mg)-based biomaterials have gained acceptability in fracture fixation due to their ability to naturally degrade in the body after fulfilling the desired functions.However,pure Mg not only degrades rapidly in the physiological environment,but also evolves hydrogen gas during degradation.In this study,Mg0.5Zr and Mg0.5ZrxZn(x=1–5 wt.%)matrix nanocomposites(MNCs)reinforced with different contents(0.1–0.5 wt.%)of graphene nanoplatelets(GNP)were manufactured via a powder metallurgy technique and their mechanical and corrosion properties were evaluated.The increase in GNP concentration from 0.2 wt.%to 0.5 wt.%added to Mg0.5Zr matrices resulted in decreases in the compressive yield strength and corrosion resistance in Hanks’Balanced Salt Solution(HBSS).On the other hand,a higher concentration(4–5 wt.%)of Zn added to Mg0.5Zr0.1GNP resulted in an increase in ductility but a decrease in compressive yield strength.Overall,an addition of 0.1 wt.%GNPs to Mg0.5Zr3Zn matrices gave excellent ultimate compressive strength(387 MPa)and compressive yield strength(219 MPa).Mg0.5Zr1Zn0.1GNP and Mg0.5Zr3Zn0.1GNP nanocomposites exhibited 29%and 34%higher experimental yield strength,respectively,as compared to the theoretical yield strength of Mg0.5Zr0.1GNP calculated by synergistic strengthening mechanisms including the difference in thermal expansion,elastic modulus,and geometry of the particles,grain refinement,load transfer,and precipitation of GNPs in the Mg matrices.The corrosion rates of Mg0.5Zr1Zn0.1GNP,Mg0.5Zr3Zn0.1GNP,Mg0.5Zr4Zn0.1GNP,and Mg0.5Zr5Zn0.1GNP measured using potentiodynamic polarization were 7.5 mm/y,4.1 mm/y,6.1 mm/y,and 8.0 mm/y,respectively.Similarly,hydrogen gas evolution tests also demonstrated that Mg0.5Zr3Zn0.1GNP exhibited a lower corrosion rate(1.5 mm/y)than those of Mg0.5Zr1Zn0.1GNP(3.8 mm/y),Mg0.5Zr4Zn0.1GNP(1.9 mm/y),and Mg0.5Zr5Zn0.1GNP(2.2 mm/y).This study demonstrates the potential of GNPs as effective nano-reinforcement particulates for improving the mechanical and corrosion properties of Mg–Zr–Zn matrices.

Enhanced electrochemical performance of Li-ion batteries with nanoporous titania as negative electrodes

Nanoporous anatase TiO_2 （np-TiO_2） electrodes have been developed via the anodization of titanium foils in fluoride containing electrolytes, and its application in rechargeable lithium-ion batteries （LIBs） was investigated. Four different types of np-TiO_2 electrodes with different pore diameters of 14.7±8.2 nm, 12.85±6.8 nm, 11.0±5.5, and 26.7±13.6 nm were fabricated for evaluating the effect of nanoporous characteristics on the LIB performance. The discharge capacity of the four battery types 1, 2, 3, and 4 were 132.7 mAh·g^-1, 316.7 mAh·g^-1, 154.3 mAh·g^-1, and 228.4 mAh·g^-1, respectively. In addition, these electrodes 1, 2, 3, and 4 exhibited reversible capacity of 106.9 mAh·g^-1 after 295th, 180.9 mAh·g^-1 after 220th, 126.1 mAh·g^-1 after 150th, and 206.7 mAh·g^-1 after 85th cycle at a rate of 1 C, respectively. It was noted that the cyclic life of the batteries had an inverse relationship, and the capacity had a proportional relationship to the pore diameter. The enhanced electrochemical performance of the nanoporous electrodes can be attributed to the improved conductivity and the enhanced kinetics of lithium insertion/extraction at electrode/electrolyte interfaces because of the large specific surface area of np-TiO_2 electrodes.

(Si+SiO)/G复合负极材料的电化学性能

针对硅基负极材料体积膨胀巨大(~300%)且具较差的循环稳定性能,采用两步高能球磨法制备(Si+SiO)/G复合负极材料,采用X射线衍射仪(XRD)、扫描电子显微镜(SEM)、恒流充放电测试和电化学阻抗谱图等技术分析其结构形貌和电化学性能。结果表明:制备的(Si+SiO)/G复合材料形貌规则,分布均匀;与硅基原始材料相比,(Si+SiO)/G复合材料的电化学性能得到显著改善,在200 mA·g^-1电流密度下,首次充电比容量为2 701.9 m Ah·g^-1,首次库仑效率为83.4%,循环60圈后可逆比容量为1 063.8 mAh·g^-1。

Advances in functional coatings on biliary stents

Biliary stenting is an important interventional method for the prevention and treatment of biliary tract diseases.However,complications,such as postoperative biliary infection and re-stenosis,frequently occur due to the extensive scope of the biliary system and the complex composition of bile.The com-bination of coating technology and biliary stents is expected to bring new approaches to the solution of these problems.The cutting-edge advance on functional coatings on biliary stents is reviewed from seven perspectives:anticorrosion,-bacterial,-tumor,stone-dissolving,X-ray visibility,anti-stent migration and functional composite coatings.The de-velopment trend is also discussed.Overall.the performance of the numerous functional coatings for various purposes is generally up to expectations,but the balance between the medica tions'effectiveness and their safety needs to be further adjusted.Many contemporary investigations have advanced to the leve of animal experiments,offering crucial fundamental assurance for broader human studies.The combination of biliary stent and functional coatings is an innovative idea with great potential for future development.

Role of Multi-scale Hierarchical Structures in Regulating Wetting State and Wetting Properties of Structured Surfaces

Amplifying the intrinsic wettability of substrate material by changing the solid/liquid contact area is considered to be the main mechanism for controlling the wettability of rough or structured surfaces.Through theoretical analysis and experimental exploration,we have found that in addition to this wettability structure amplification effect,the surface structure also simultaneously controls surface wettability by regulating the wetting state via changing the threshold Young angles of the Cassie-Baxter and Wenzel wetting regions.This wetting state regulation effect provides us with an alternative strategy to overcome the inherent limitation in surface chemistry by tailoring surface structure.The wetting state regulation effect created by multi-scale hierarchical structures is quite significant and plays is a crucial role in promoting the superhydrophobicity,superhydrophilicity and the transition between these two extreme wetting properties,as well as stabilizing the Cassie-Baxter superhydrophobic state on the fabricated lotus-like hierarchically structured Cu surface and the natural lotus leaf.

Enhanced stability and electrochemical properties of lanthanum and cerium co-modified LiVOPO_(4) cathode materials for Li-ion batteries

A facile and efficient ball-milling assisted sol-gel synthesis route was developed to prepare triclinic e-LiVOPO_(4)(LVOP)material with lanthanum(La)and cerium(Ce)modification individually as well as simultaneously.An LVOP/LaPO_(4)/CePO_(4)composite cathode material was successfully synthesized and results show that La and Ce co-modification noticeably improves the electrochemical performance by enhancing the high voltage capacity upon cycling,which indicates contributions from the good ionic conductors LaPO_(4)and CePO_(4).The simultaneous La and Ce modification improves the high voltage performance significantly with an increase of 50%in high voltage capacity after 20 cycles compared to pure LVOP.It also shows stabilized cycling perfo rmance with 91%capacity rete ntion after 50 cycles at 0.1 C rate,along with high-rate capability with a capacity of 83.1 mAh/g compared to the pristine sample showing the capacity of 51.6 mAh/g at a high rate of 5C.This can be attributed to the good conductivity of LaPO_(4)and CePO_(4).In addition,the LVOP/LaPO_(4)/CePO_(4)composite and the pristine LVOP give a charge transfer resistance of-105 and-212Ω,respectively,showing much lower impedance due to a combination of La and Ce addition.

Development of Ti-26Nb-1.2TiC shape memory composite for biomedical applications

Ti-Nb alloys have great potential in biomedical applications as bone-implant materials due to their low elastic modulus,superelasticity,high corrosion resistance,and good biocompatibility.However,the low yield strength and poor superelasticity of Ti-Nb alloys restrict their practical clinical applications.Here,we report the mechanical properties and superelasticity,corrosion behavior,and biocompatibility of a Ti-26 at.%Nb-1.2 vol.%TiC(Ti-26Nb-1.2TiC)shape memory composite(SMC)prepared by vacuum arc melting and hot rolling.The yield strength,critical stress for inducing martensitic transformation,and elongation of the Ti-26Nb-1.2TiC SMC and a Ti-26Nb alloy were 460 and 337 MPa,251 and 115 MPa,and 27.2%and 24.1%,respectively.The recovery rate of the SMC under 4%pre-strain reached 91.4%,which was 1.2 times that of the Ti-26Nb.Electrochemical tests in Hanks’solution revealed that the corrosion current density,passive current density,and corrosion rate of the SMC were lower than those of the Ti-26Nb.Both the Ti-26Nb alloy and Ti-26Nb-1.2TiC SMC showed good cell viability with grade 0 cytotoxicity in relation to MG-63 osteosarcoma cells.

A comprehensive review on metallic biomaterials for airway stenosis repair

In recent years,the incidence of airway stenosis in respiratory diseases increases year by year.Among many treatment methods,tracheal stent implantation is a very effective way.Metallic stents have been the first choice for tracheal stent implantation due to their excellent mechanical properties,low rate of migration,and minimal effect on the ciliary movement of the trachea.In this paper,the research progress of metal tracheal stents is introduced in detail from three aspects of mechanical properties,degradation properties,and biocompatibility,including traditional inert metallic tracheal stents and new degradable metallic tracheal stents,and its future research and development are prospected:although the current research on biodegradable metal tracheal stents is still in its infancy,with only some studies of magnesium-based,iron-based,and zinc-based tracheal stents,they are considered as the best material for preparing future metal tracheal scaffolds considering their biodegradability and biocompatibility.

Additive manufacturing of metallic and polymeric load-bearing biomaterials using laser powder bed fusion:A review

Surgical prostheses and implants used in hard-tissue engineering should satisfy all the clinical,mechanical,manufacturing,and economic requirements in order to be used for load-bearing applications.Metals,and to a lesser extent,polymers are promising materials that have long been used as load-bearing biomaterials.With the rapid development of additive manufacturing(AM)technology,metallic and polymeric implants with complex structures that were once impractical to manufacture using traditional processing methods can now easily be made by AM.This technology has emerged over the past four decades as a rapid and cost-effective fabrication method for geometrically complex implants with high levels of accuracy and precision.The ability to design and fabricate patient-specific,customized structural biomaterials has made AM a subject of great interest in both research and clinical settings.Among different AM methods,laser powder bed fusion(L-PBF)is emerging as the most popular and reliable AM method for producing load-bearing biomaterials.This layer-by-layer process uses a high-energy laser beam to sinter or melt powders into a part patterned by a computer-aided design(CAD)model.The most important load-bearing applications of L-PBF-manufactured biomaterials include orthopedic,traumatological,craniofacial,maxillofacial,and dental applications.The unequalled design freedom of AM technology,and L-PBF in particular,also allows fabrication of complex and customized metallic and polymeric scaffolds by altering the topology and controlling the macro-porosity of the implant.This article gives an overview of the L-PBF method for the fabrication of load-bearing metallic and polymeric biomaterials.