Zinc (Zn)-based biodegradable metals (BMs) fabricated through conventional manufacturing methods exhibit adequate mechanical strength, moderate degradation behavior, acceptable biocompatibility, and bioactive functions. Consequently, they are recognized as a new generation of bioactive metals and show promise in several applications. However, conventional manufacturing processes face formidable limitations for the fabrication of customized implants, such as porous scaffolds for tissue engineering, which are future direction towards precise medicine. As a metal additive manufacturing technology, laser powder bed fusion (L-PBF) has the advantages of design freedom and formation precision by using fine powder particles to reliably fabricate metallic implants with customized structures according to patient-specific needs. The combination of Zn-based BMs and L-PBF has become a prominent research focus in the fields of biomaterials as well as biofabrication. Substantial progresses have been made in this interdisciplinary field recently. This work reviewed the current research status of Zn-based BMs manufactured by L-PBF, covering critical issues including powder particles, structure design, processing optimization, chemical compositions, surface modification, microstructure, mechanical properties, degradation behaviors, biocompatibility, and bioactive functions, and meanwhile clarified the influence mechanism of powder particle composition, structure design, and surface modification on the biodegradable performance of L-PBF Zn-based BM implants. Eventually, it was closed with the future perspectives of L-PBF of Zn-based BMs, putting forward based on state-of-the-art development and practical clinical needs.
This study is concerned with the surface integrity of Inconel 738LC parts manufactured by selective laser melting(SLM)followed by high-speed milling(HSM).In the investigation process of surface integrity,the study emp...
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This study is concerned with the surface integrity of Inconel 738LC parts manufactured by selective laser melting(SLM)followed by high-speed milling(HSM).In the investigation process of surface integrity,the study employs ultradepth three-dimensional microscopy,laser scanning confocal microscopy,scanning electron microscopy,electron backscatter diffractometry,and energy dispersive spectroscopy to characterize the evolution of material microstructure,work hardening,residual stress coupling,and anisotropic effect of the building direction on surface integrity of the *** results show that SLM/HSM hybrid manufacturing can be an effective method to obtain better surface quality with a thinner machining metamorphic ***-speed machining is adopted to reduce cutting force and suppress machining heat,which is an effective way to produce better surface mechanical properties during the SLM/HSM hybrid manufacturing *** general,high-speed milling of the SLM-built Inconel 738LC samples offers better surface integrity,compared to simplex additive manufacturing or casting.
Magnesium alloy is a promising biodegradable metal material for hard tissue ***,its high corrosion rate limits its *** our previous study,we biomimetically deposited a calcium carbonate coating on the surface of magne...
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Magnesium alloy is a promising biodegradable metal material for hard tissue ***,its high corrosion rate limits its *** our previous study,we biomimetically deposited a calcium carbonate coating on the surface of magnesium alloy using siloxane *** calcium carbonate coating demonstrated excellent in vitro biocompatibility and provided partial protection for the magnesium alloy *** this study,we further enhanced the corrosion resistance of the calcium carbonate coating by treating it with stearic acid and its derivative,sodium *** corrosion tests revealed that the sodium stearate-treated calcium carbonate coating reduced the corrosion rate by two orders of ***,in vitro biocompatibility assessments showed that while the biocompatibility of the sodium stearate-treated coating was slightly reduced,it remained acceptable compared to the magnesium *** study builds on our previous work and offers a promising reinforcement strategy for degradable magnesium alloys in medical applications.
Relaxation dynamics,essential for the structural evolution of non-equilibrium systems like glassy materials,remain ***,we explore relaxation dynamics and viscoelastic properties in three types of metallic glasses with...
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Relaxation dynamics,essential for the structural evolution of non-equilibrium systems like glassy materials,remain ***,we explore relaxation dynamics and viscoelastic properties in three types of metallic glasses with distinctβrelaxation *** systems with significantβrelaxation,stress relaxation and creep experiments reveal a transition from two-step to one-step relaxation with rising ***,such a phenomenon is absent in systems with weakerβ*** model the two-step relaxation process using a double Kohlrausch-Williams-Watts equation,and the obtained relaxation times elegantly adhere to the Arrhenius *** combining fitted activation energies with theoretical analysis,we conclusively attribute these relaxation processes toβrelaxation andαrelaxation,***,we analyze the relaxation time spectra of two processes and establish a comprehensive picture linking dynamic relaxation with *** study provides new strategies for probing the complex relaxation behaviors of glasses from the perspective of viscoelasticity.
Aluminium doped zinc oxide (AZO) nanomaterials (AlxZn1-xO) with x fraction varying as 0.02 and 0.04 were synthesized using the auto-combustion method using glycine as a fuel. The synthesized catalysts were characteriz...
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Quantum dot color converters (QDCCs) currently have the unsolved problems of photostability and discolorization in appearance after long-term operation in microdisplays. Instead of polymer-to-carbon conversion and/or ...
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Neurosurgery is a highly specialized field:it often involves surgical manipulation of noble structures and cerebral retraction is frequently necessary to reach deep-seated brain *** are still no reliable methods preve...
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Neurosurgery is a highly specialized field:it often involves surgical manipulation of noble structures and cerebral retraction is frequently necessary to reach deep-seated brain *** are still no reliable methods preventing possible retraction *** objective of this study was to design work chambers well suited for transcranial endoscopic surgery while providing safe retraction of the surrounding brain *** chamber is designed to be inserted close to the intracranial point of interest;once it is best placed it can be *** should guarantee an appreciable workspace similar to that of current neurosurgical *** experimental aspect of this study involved the use of a force sensor to evaluate the pressures exerted on the brain tissue during the retraction *** pterional craniotomy,pressure measurements were made during retraction with the use of a conventional metal spatula with different *** that,although the force values necessary for retraction and exerted on the spatula by the neurosurgeon are the same,the local pressure exerted on the parenchyma at the edge of the spatula at different inclinations varied greatly.A new method of cerebral retraction using a chamber retractor(CR)has been designed to avoid any type of complication due to spatula edge overpressures and to maintain acceptable pressure values exerted on the parenchyma.
Tungsten-based alloys doped with the 10 wt% FeCoNiCu medium entropy alloy (MEA) binder were fabricated by mechanical alloying. The role of the Cu-containing MEA binder and sintering temperatures (1250–1450℃) on the ...
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Irradiation increases the yield stress and embrittles light water reactor(LWR)pressure vessel *** this study,we demonstrate some of the potential benefits and risks of using machine learning models to predict irradiat...
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Irradiation increases the yield stress and embrittles light water reactor(LWR)pressure vessel *** this study,we demonstrate some of the potential benefits and risks of using machine learning models to predict irradiation hardening extrapolated to low flux,high fluence,extended life *** machine learning training data included the Irradiation Variable for lower flux irradiations up to an intermediate fluence,plus the Belgian Reactor 2 and Advanced Test Reactor 1 for very high flux irradiations,up to very high ***,the machine learning model predictions for the high fluence,intermediate flux Advanced Test Reactor 2 irradiations are superior to extrapolations of existing hardening *** successful extrapolations showed that machine learning models are capable of capturing key intermediate flux effects at high *** approaches,applied to expanded databases,could be used to predict hardening in LWRs under life-extension conditions.
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