摘要
为了提高NiTi合金的生物活性并赋予其一定的抗菌性,采用放电等离子烧结技术制备了表面多孔Ti-Ag/NiTi梯度合金,利用X射线衍射(XRD)、光学显微镜(OM)、扫描电镜(SEM)、室温压缩、人工模拟体液浸泡、贴膜法等方法研究了不同Ag含量对梯度合金微观组织、界面结合、表面孔隙特征、力学性能、体外生物活性及抗菌性能的影响及机理.研究表明:梯度合金中间基体主要由奥氏体NiTi相(B2)和单斜马氏体NiTi相(B19′)组成,并同时存在少量次生相Ti2Ni相,表面多孔层主要由α-Ti、TiAg和Ti2Ag相组成,内外层界面形成稳定冶金结合;Ag含量增加对梯度合金表面孔隙率和平均孔径影响不大,但抗压强度值提高而弹性模量变化不明显,这主要与表面多孔层中TiAg和Ti2Ag相的强化作用有关;梯度合金在人工模拟体液中浸泡14 d后表面形成了大量类骨磷灰石层,显示了优异的体外生物活性,同时,Ag的加入显著提高了梯度合金的抗菌性能.
In order to improve the bioactivity of NiTi alloy and endow certain antibacterial properties with it,surface porous Ti-Ag/NiTi gradient alloy was fabricated by spark plasma sintering(SPS)technology.The effects of different Ag contents on the microstructure,interface bonding,surface pore characteristics,mechanical properties,in vitro biological activity and antibacterial property of the alloy were investigated by X-ray diffraction(XRD),optical microscope(OM),scanning electron microscope(SEM),room temperature compression,simulated body fluid immersion and sticker method.The results showed that the matrix of the gradient alloys mainly consist of NiTi phase and a few complex phases of Ti2Ni,and the surface porous layers mainly consist ofα-Ti,TiAg and Ti2Ag phases.Moreover,we can observe a stable metallurgical bonding on the internal and external interface of the gradient alloy.With the increase of Ag content,the porosity and average pore size of surface porous layer did not vary significantly,but compressive strength of the alloy increased and the compressive elastic modulus showed no obvious change,which was mainly related to the strengthening of TiAg and Ti2Ag phases in the surface porous layer.Furthermore,a lot of bone-like apatite was deposited on the surface of gradient alloy after soaking in SBF for 14 d,showing excellent in vitro biological activity.Meanwhile,the addition of Ag significantly improved the antibacterial properties of the gradient alloy.
作者
邓霞
何远怀
焦美琪
张玉勤
蒋业华
DENG Xia;HE Yuanhuai;JIAO Meiqi;ZHANG Yuqin;JIANG Yehua(School of Materials Science and Engineering,Kunming University of Science and Technology,Kunming 650093,China;National-local Joint Engineering Laboratory of Metal Advanced Solidification Forming and Equipment Technology,Kunming 650093,China;Engineering Technology Research Center of Titanium Products and Application of Yunnan Province,Chuxiong 651209,China)
出处
《材料科学与工艺》
EI
CAS
CSCD
北大核心
2019年第5期27-33,共7页
Materials Science and Technology
基金
国家自然科学基金资助项目(31660262)
关键词
NiTi梯度合金
放电等离子烧结
微观组织
力学性能
抗菌性能
NiTi gradient alloy
spark plasma sintering
microstructure
mechanical properties
antibacterial property
