Bio-high entropy alloys: Progress, challenges, and opportunities

Abstract

With the continuous progress and development in biomedicine, metallic biomedical materials have attracted significant attention from researchers. Due to the low compatibility of traditional metal implant materials with the human body, it is urgent to develop new biomaterials with excellent mechanical properties and appropriate biocompatibility to solve the adverse reactions caused by long-term implantation. High entropy alloys (HEAs) are nearly equimolar alloys of five or more elements, with huge compositional design space and excellent mechanical properties. In contrast, biological high-entropy alloys (Bio-HEAs) are expected to be a new bio-alloy for biomedicine due to their excellent biocompatibility and tunable mechanical properties. This review summarizes the composition system of Bio-HEAs in recent years, introduces their biocompatibility and mechanical properties of human bone adaptation, and finally puts forward the following suggestions for the development direction of Bio-HEAs: to improve the theory and simulation studies of Bio-HEAs composition design, to quantify the influence of composition, process, post-treatment on the performance of Bio-HEAs, to focus on the loss of Bio-HEAs under actual service conditions, and it is hoped that the clinical application of the new medical alloy Bio-HEAs can be realized as soon as possible.

Research progress of metal biomaterials with potential applications as cardiovascular stents and their surface treatment methods to improve biocompatibility

“…High entropy alloys (HEAs) are near equimolar alloys containing five or more elements [ 55 ], attracting significant interest due to their range of functional properties, including good mechanical properties and biocompatibility [ 56 ]. Compared to conventional medical alloys, HEAs offer better design freedom, integrating medical capabilities to suit diverse medical needs such as a low modulus of elasticity, high biocompatible elements, and potential shape-memory capabilities [ 57 ].…”

Deformation Behavior of 3D‐Printed High‐Entropy Alloys: A Critical Review

“…[7] Biological HEAs (bio-HEAs) composed of Mo, Nb, Ta, Ti, Hf, etc., have shown promising biocompatibility for biomedical applications. [48] The tunability of Young's modulus, especially to lower values, is critical for bio-HEAs to prevent the stressshielding effect in conventional implants which leads to anatomical and healing issues. [49,50] In addition, more complex parts are required in implant-based and orthopedic applications, which are especially achievable via 3D printing.…”

Synthesis of High Entropy Alloy Nanoparticles by Pulsed Laser Ablation in Liquids: Influence of Target Preparation on Stoichiometry and Productivity

“…[6,7] Moreover, HEAs have emerged as potential replacements for conventional alloys in biomedical applications due to their exceptional corrosion resistance, low degradation in physiological environments, biocompatibility, wear resistance, and bacterial infection prevention. [8,9] Additionally, HEAs have been proposed as replacements for traditional materials in nuclear reactors, thanks to their high resistance to irradiation damage and excellent stability at high temperatures, making them suitable for use in harsh nuclear environments. [10,11] Downsizing HEAs to the nanoscale provides additional application possibilities resulting from the high surface-tovolume ratio and quantum confinement effect, making them suitable for catalysis [12][13][14][15] energy storage, [16,17] magnetic, [18][19][20] and biomedical applications.…”

“…Industries such as aerospace employ HEAs extensively for components like compressors, combustion chambers, exhaust nozzles, and gas turbine parts, where properties such as strength‐to‐weight ratio, oxidation resistance, fatigue resistance, and elevated temperature strength are crucial [6,7] . Moreover, HEAs have emerged as potential replacements for conventional alloys in biomedical applications due to their exceptional corrosion resistance, low degradation in physiological environments, biocompatibility, wear resistance, and bacterial infection prevention [8,9] . Additionally, HEAs have been proposed as replacements for traditional materials in nuclear reactors, thanks to their high resistance to irradiation damage and excellent stability at high temperatures, making them suitable for use in harsh nuclear environments [10,11] …”