Nano-SiC reinforced Zn biocomposites prepared via laser melting:Microstructure,mechanical properties and biodegradability  

作　　者：Chengde Gao Meng Yao Cijun Shuai Shuping Peng Youwen Deng 

机构地区：[1]State Key Laboratory of High Performance Complex Manufacturing,College of Mechanical and Electrical Engineering,Central South University,Changsha 410083,China [2]Jiangxi University of Science and Technology,Ganzhou 341000,China [3]Shenzhen Institute of Information Technology,Shenzhen 518172,China [4]NHC Key Laboratory of Carcinogenesis and The Key Laboratory of Carcinogenesis and Cancer Invasion of the Chinese Ministry of Education,Xiangya Hospital,Central South University,Changsha 410013,China [5]Cancer Research Institute,School of Basic Medical Sciences,Central South University,Changsha 410011,China [6]Department of Emergency,The Second Xiangya Hospital of Central South University,Changsha 410011,China

出　　处：《Journal of Materials Science & Technology》2019年第11期2608-2617,共10页材料科学技术（英文版）

基　　金：supported financially by the National Natural Science Foundation of China (Nos.51705540,81871494 and 81871498);the Hunan Provincial Natural Science Foundation of China (Nos.2018JJ3671 and 2019JJ50588);the GuangdongProvince Higher Vocational Colleges & Schools Pearl River Scholar Funded Scheme (2018);the Open Sharing Fund for the Largescale Instruments and Equipments of Central South University;the Project of Hunan Provincial Science and Technology Plan (No.2017RS3008);the Shenzhen Science and Technology Plan Project (No.JCYJ20170817112445033);the National Postdoctoral Program for Innovative Talents (No.BX201700291);the Hunan Science and Technology Innovation Plan (Nos.2018SK2105 and kq1606001);the China Postdoctoral Science Foundation (No. 2018M632983)

摘　　要：Zn has been regarded as new kind of potential implant biomaterials due to the desirable biodegradability and good biocompatibility,but the low strength and ductility limit its application in bone repairs.In the present study,nano-SiC was incorporated into Zn matrix via laser melting,aiming to improve the mechanical performance.The microstructure analysis showed that nano-SiC distributed along Zn grain boundaries.During the laser rapid solidification,nano-SiC particles acted as the sites for heterogeneous nucleation,which resulted in the reduction of Zn grain size from 250μm to 15μm with 2 wt%SiC(Zn-2 SiC).Meanwhile,nano-SiC acted as a reinforcer by virtue of Orowan strengthening and dispersion strengthening.As a consequence,the nanocomposites showed maximal compressive yield strength(121.8±5.3 MPa)and high microhardness(72.24±3.01 HV),which were increased by 441%and 78%,respectively,compared with pure Zn.Moreover,fracture analysis indicated a more ductile fracture of the nanocomposites after the incorporation of nano-SiC In addition,the nanocomposites presented favorable biocompatibility and accelerated degradation caused by intergranular corrosion.These findings suggested that the nano-SiC reinforced Zn biocomposites may be the potential candidates for orthopedic implants.Zn has been regarded as new kind of potential implant biomaterials due to the desirable biodegradability and good biocompatibility,but the low strength and ductility limit its application in bone repairs.In the present study,nano-SiC was incorporated into Zn matrix via laser melting,aiming to improve the mechanical performance.The microstructure analysis showed that nano-SiC distributed along Zn grain boundaries.During the laser rapid solidification,nano-SiC particles acted as the sites for heterogeneous nucleation,which resulted in the reduction of Zn grain size from 250 μm to 15 μm with 2 wt%SiC(Zn-2 SiC).Meanwhile,nano-SiC acted as a reinforcer by virtue of Orowan strengthening and dispersion strengthening.As a consequence,the nanocomposites showed maximal compressive yield strength(121.8±5.3 MPa) and high microhardness(72.24±3.01 HV),which were increased by 441% and 78%,respectively,compared with pure Zn.Moreover,fracture analysis indicated a more ductile fracture of the nanocomposites after the incorporation of nano-SiC In addition,the nanocomposites presented favorable biocompatibility and accelerated degradation caused by intergranular corrosion.These findings suggested that the nano-SiC reinforced Zn biocomposites may be the potential candidates for orthopedic implants.

关 键 词：ZN NANO-SIC BIOCOMPOSITES Laser melting Mechanical properties 

分 类 号：TB333[一般工业技术—材料科学与工程]