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采用准静态和动态纳米压痕技术研究了羟基磷灰石/聚乳酸(HA/PLA)复合材料在微纳尺度的表面力学性能。在静态模式下研究了保载,卸载时间对模量和硬度测试结果的影响。结果发现,当保载时间小于45s时,由于蠕变使保载和卸载时间对测试结果产生显著影响;保载时间短且卸载时间长时在卸载段会形成“鼻子”,为了避免“鼻子”选择保载时间为45s。在动态模式下研究了材料的动态力学性能,结果表明存储模量和硬度均随着压入深度的增加而减小。压痕和划痕实验结果均表明:HA显著的提高了PLA的力学性能,与纯PLA相比,9wt%HA/PLA复合物的模量增加了35.5%,硬度增加了44.7%,蠕变深度下降了9.5%,相同载荷下的最大划痕深度和残余深度均小于纯PLA,表现出好的弹性恢复能力和抗变形能力。
The surface mechanical properties of hydroxyapatite / polylactic acid (HA / PLA) composites at the micro / nano scale were studied by quasi-static and dynamic nanoindentation techniques. In the static mode, the influence of the ballast and unload time on the modulus and hardness test results was studied. The results show that when the loading time is less than 45s, the loading and unloading time will have a significant effect on the test results due to creep. When the loading time is short and the unloading time is long, “nose” will be formed in the unloading section. In order to avoid “nose” Choose the warranty time of 45s. The dynamic mechanical properties of the materials were studied in dynamic mode. The results show that both the storage modulus and the hardness decrease with the increase of the depth of indentation. The results of indentation and scratching show that HA significantly improves the mechanical properties of PLA. Compared with pure PLA, the modulus of 9wt% HA / PLA composite increases by 35.5%, the hardness increases by 44.7% and the creep depth Decreased by 9.5%. The maximum scratch depth and residual depth under the same load were less than that of pure PLA, showing good elastic recovery and anti-deformation ability.