Ti-Mo alloys/composites are expected to be the next-generation implant material with low moduli but without toxic/allergic elements.However,synthesis mechanisms of the Ti-Mo biomaterials in Selective Laser Melting(SLM)vary according to raw materials and fundamentally influence material performance,due to inhomogeneous chemical compositions and stability.Therefore,this work provides a comparative study on microstructure,mechanical and wear performance,and underlying thermal mechanisms of two promising Ti-Mo biomaterials prepared by SLM but through different synthesis mechanisms to offer sci-entific understanding for creation of ideal metal implants.They are(i)Ti-7.5Mo alloys,prepared from a conventional Ti/Mo powder mixture,and(ii)Ti-7.5Mo-2.4TiC composites,in-situ prepared from Ti/Mo2C powder mixture.Results reveal that the in-situ Ti-7.5Mo-2.4TiC composites made from Ti/Mo2C powder mixture by SLM can produce 61.4％more β phase and extra TiC precipitates(diameter below 229.6 nm)than the Ti-7.5Mo alloys.The fine TiC not only contributes to thinner and shorter β columnar grains under a large temperature gradient of 51.2 K/μm but also benefits material performance.The in-situ Ti-7.5Mo-2.4TiC composites produce higher yield strength(980.1±29.8 MPa)and ultimate compressive strength(1561.4±39 MPa)than the Ti-7.5Mo alloys,increasing by up to 12.1％.However,the fine TiC with an aspect ratio of 2.71 dominates an unfavourable rise of elastic modulus to 91.9±2 GPa,44.7％higher than the Ti-7.5Mo alloys,which,nevertheless,is still lower than the modulus of traditional Ti-6A1-4V.While,TiC and its homogeneous distribution benefit wear resistance,decreasing the wear rate of the in-situ Ti-7.5Mo-2.4TiC composites to 6.98 x 10-4 mm3 N-1 m-1,which is 36％lower than that of the Ti-7.5Mo alloys.Therefore,although with higher modulus than the Ti-7.5Mo alloys,the SLM-fabricated in-situ Ti-7.5Mo-2.4TiC composites can expect to provide good biomedical application potential in cases where combined good strength and wear resistance are required.

Qimin Shi;Shoufeng Yang;Yi Sun;Yifei Gu;Ben Mercelis;Shengping Zhong;Bart Van Meerbeek;Constantinus Politis

KU Leuven,Department of Biomedical Sciences,OMFS-IMPATH Research Group & UZ Leuven(University Hospitals Leuven),Oral and Maxillofacial Surgery,Kapucijnenvoer 33,Leuven 3000,Belgium;University of Southampton,Faculty of Engineering and Physical Sciences,Southampton S017 1BJ,United Kingdom;KU Leuven,Department of Oral Health Sciences,BIOMAT-Biomaterials Research Group & UZ Leuven(University Hospitals Leuven),Dentistry,Kapucijnenvoer 7,Leuven 3000,Belgium

材料科学技术（英文版）

[1]Qimin Shi;Shoufeng Yang;Yi Sun;Yifei Gu;Ben Mercelis;Shengping Zhong;Bart Van Meerbeek;Constantinus Politis-.In-situ formation of Ti-Mo biomaterials by selective laser melting of Ti/Mo and Ti/Mo2C powder mixtures:A comparative study on microstructure,mechanical and wear performance,and thermal mechanisms)[J].材料科学技术（英文版）,2022(20):81-96

4TiC

In,situ,formation,biomaterials,by,selective,laser,melting,Mo2C,powder,mixtures,comparative,study,microstructure,mechanical,wear,performance,thermal,mechanisms,alloys,composites,expected,next,generation,moduli,without,toxic,allergic,elements,However,synthesis,Selective,Laser,Melting,SLM,vary,according,raw,fundamentally,influence,due,inhomogeneous,chemical,compositions,stability,Therefore,this,work,provides,underlying,two,promising,prepared,through,different,offer,sci,entific,understanding,creation,ideal,metal,implants,They,5Mo,from,conventional,ii,Results,reveal,that,made,can,produce,more,phase,extra,precipitates,diameter,below,than,fine,not,only,contributes,thinner,shorter,columnar,grains,large,temperature,gradient,also,benefits,higher,yield,strength,ultimate,compressive,increasing,up,aspect,dominates,unfavourable,rise,elastic,modulus,GPa,which,nevertheless,still,lower,traditional,6A1,4V,While,distribution,resistance,decreasing,rate,mm3,although,fabricated,good,biomedical,application,potential,cases,where,combined,required

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