Nanomechanics and Nanotribology Lab and High Temperature Tribology Lab, Department of Mechanical and Materials Engineering, Florida International University, Miami, FL 33174, USA.
J Mech Behav Biomed Mater. 2011 Jan;4(1):44-56. doi: 10.1016/j.jmbbm.2010.09.005. Epub 2010 Sep 21.
This study proposes boron nitride nanotube (BNNT) reinforced hydroxyapatite (HA) as a novel composite material for orthopedic implant applications. The spark plasma sintered (SPS) composite structure shows higher density compared to HA. Minimal lattice mismatch between HA and BNNT leads to coherent bonding and strong interface. HA-4 wt% BNNT composite offers excellent mechanical properties-120% increment in elastic modulus, 129% higher hardness and 86% more fracture toughness, as compared to HA. Improvements in the hardness and fracture toughness are related to grain refinement and crack bridging by BNNTs. HA-BNNT composite also shows 75% improvement in the wear resistance. The wear morphology suggests localized plastic deformation supported by the sliding of outer walls of BNNT. Osteoblast proliferation and cell viability show no adverse effect of BNNT addition. HA-BNNT composite is, thus, envisioned as a potential material for stronger orthopedic implants.
本研究提出了一种新型复合材料，即氮化硼纳米管（BNNT）增强羟基磷灰石（HA），用于骨科植入物应用。火花等离子烧结（SPS）复合结构的密度高于 HA。HA 和 BNNT 之间的晶格失配最小，导致了相干结合和强界面。与 HA 相比，HA-4wt%BNNT 复合材料具有优异的机械性能，弹性模量提高了 120%，硬度提高了 129%，断裂韧性提高了 86%。硬度和断裂韧性的提高与 BNNTs 的晶粒细化和裂纹桥接有关。HA-BNNT 复合材料的耐磨性也提高了 75%。磨损形貌表明，BNNT 的外壁滑动支持局部塑性变形。成骨细胞增殖和细胞活力没有显示 BNNT 添加的不良影响。因此，HA-BNNT 复合材料有望成为更强的骨科植入物的潜在材料。
