Construction of the crack-less maicro-cutting technology of the biodegradable polylactic acid material used for a medical-application fixture

在脑外科手术中，聚乳酸材料的固定装置有望得到应用，因为它既不是用于生产生物相容性优异的聚乳酸，也不是人工制品。本研究旨在建立一种控制加工表面微裂纹产生的微加工方法。利用高速摄像机对基本正交切削的微切削行为进行了详细观察，发现该材料在切削过程中剪切角表现出与塑料材料相同的趋势，且剪切角非常大。此外，对材料的粘弹性性能和切削温度进行了测试，结果表明，当切削温度与玻璃化转变温度相似时，可形成无裂纹加工表面。

In brain surgery, application to the fixture of polylactic acid material is expected, Because, it is for polylactic acid producing neither excelling in biocompatibility, nor an artifact. This research is aimed at construction of the micro fabrication method which controls the micro-crack generated on the machined surface.As a result of detailed observation about the micro-cutting behavior in a fundamental orthogonal cutting using a high-speed video camera, shear angle during cutting of this material showed the same tendency as a plastic material, and shows a very large angle. Moreover, the viscoelastic property and the cutting temperature of material were measured and it showed clearly to create the machined surface of crack-less in case of the cutting-temperature conditions similar to glass transition temperature.