image: Schematic representation of the manufacturing process as well as corrosion resistance, in vitro cytocompatibility, and in vivo biosafety.
Credit: Xia Li and Tao Yang from City University of Hong Kong.
The research teams from the City University of Hong Kong and Songshan Lake Materials Laboratory have developed a novel Ti-24Nb-4Zr-8Sn (Ti2448) alloy produced via a cost-effective powder metallurgy method, with low Young’s Modulus, superior corrosion resistance, and good biocompatibility.. The corrosion rate of the Ti2448 alloy, treated with hot isostatic processing and water quenching (SHIPQ), is more than 3.5 times lower than that of the Ti-6Al-4V (Ti64) counterpart, a widely used material for dental and orthopedic implants. In addition, the SHIPQ sample shows superior biocompatibility compared to the Ti64 alloy. Their research paves the way for safer, more affordable orthopedic and dental implants with enhanced performance and long-term stability.
Biomedical implants, including joint replacements, dental fixtures, and osteosynthesis devices, rely heavily on materials that can withstand the harsh conditions of the human body while promoting tissue integration. Titanium and its alloys have been the materials of choice due to their excellent strength-to-weight ratio, biocompatibility, and corrosion resistance. However, widely used alloys like Ti64 present a key limitation: their high Young’s modulus (~100-480 GPa). This mechanical mismatch with natural bone (~ 20 GPa) can result in stress shielding, where the implant bears too much load, reducing the mechanical stimulus needed to maintain healthy bone density. Over time, this can lead to bone resorption and implant loosening, compromising implant longevity. Furthermore, the cost and manufacturing complexity of some high-performance alloys hinder their widespread clinical adoption.
In this context, research efforts have focused on developing β-type titanium alloys with lower Young’s modulus, enhanced biocompatibility, and improved mechanical properties. Alloys such as Ti2448 have shown promising results, combining a more compatible elastic modulus with good corrosion resistance and biocompatibility. Yet, challenges still remain, especially regarding manufacturing costs and the long-term stability of these materials. Traditional manufacturing techniques, like forging and casting, often involve high costs and limited design flexibility, restricting their application for patient-specific implants.
To address these challenges, a group of researchers from City University of Hong Kong and Songshan Lake Materials Laboratory has applied a cost-effective, near-net-shape powder metallurgy process to fabricate the Ti2448 alloy. This process allows for scalable production, precise control over microstructure, and the possibility of producing complex geometries suitable for various biomedical applications. A deep characterization revealed that the manufactured alloy possesses a low Young’s modulus (~57-68 GPa) aligned closely with natural bone, which is key to reducing stress shielding. They also found that Ti2448 alloy treated with hot isostatic processing and water quenching (SHIPQ), was more than 3.5 times lower than that of the Ti64 counterpart. Moreover, biological evaluations, including cell experiments and animal studies, confirmed superior biocompatibility and promising osseointegration.
The fabrication of the Ti2448 alloy involved a cost-effective, near-net-shape powder metallurgy (PM) process. Initially, high-purity metal powders of Ti, Nb, Zr, and Sn were thoroughly mixed to create the alloy powder. The mixture was then compacted into the desired shape using powder compaction techniques. Subsequently, the compacted powder underwent sintering to promote diffusion bonding and densification. To enhance mechanical properties and microstructure, heat treatments such as water quenching and hot isostatic pressing (HIP) were applied. These steps resulted in a dense, uniform microstructure with a predominant β-phase structure suitable for biomedical applications.
Microstructural analysis showed a stable oxide layer composed of TiO₂, Nb₂O₅, SnO₂, and ZrO₂, contributing to both corrosion resistance and biocompatibility. The in vivo assessments further demonstrated strong bone tissue contact, minimal inflammatory response, and enhanced bone regeneration around the implant site, especially compared to conventional Ti64 implants. These results highlight the alloy’s potential as a safe, reliable, and affordable alternative in orthopedic and dental care.
The Future: Future research should focus on comprehensive in vivo and clinical studies to further validate the long-term safety, stability, and osseointegration of Ti2448 implants. Understanding the biological response over extended implantation periods, as well as potential effects such as ion release and inflammatory reactions, will be critical for their clinical translation. In addition, further optimization of the powder metallurgy process—such as refining sintering and hot isostatic pressing parameters—will be essential to ensure uniformity, strength, and reliability in large-scale manufacturing. Exploration of advanced manufacturing techniques, such as additive manufacturing, may also provide greater design flexibility, enabling the fabrication of patient-specific implants with complex geometries. Surface modification strategies, including nanoscale patterning and bioactive coatings, represent another promising direction for enhancing cellular response and tissue integration. Furthermore, attention should be given to the environmental impact and sustainability of Ti2448 alloy production, particularly as demand for biomedical implants continues to increase. Life cycle analysis and recycling strategies will help support the responsible deployment of these advanced materials.
The Impact: This work offers a valuable and systematic analysis for biomedical Ti2448 alloys and provides insight for developing improved biomedical titanium alloys for future clinical applications.
The research has been recently published in the online edition of Materials Futures, a prominent international journal in the field of interdisciplinary materials science research.
Reference: Xia Li, Jincheng Tang, Jiang Ju, Jie Gan, Jixun Zhang, Ming Yan, Peng Yu, Haibo Ke, Weihua Wang, Tao Yang. Superior corrosion resistance and good biocompatibility of Ti-24Nb-4Zr-8Sn alloy fabricated by a cost-effective, net-shape powder metallurgy method[J]. Materials Futures, 2025, 4(3): 035401. DOI: 10.1088/2752-5724/adf080
Journal
Materials Futures