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Basic study on 3D micro texture forming for implants -Diamond cutting and roll forming of micro texture on Titanium alloy-

种植体3D微织构成形基础研究-钛合金微织构的金刚石切削和滚压成形-

基本信息

批准号：
14350069
负责人：
MASUDA Masami
金额：
$ 9.73万
依托单位：
Niigata University
依托单位国家：
日本
项目类别：
Grant-in-Aid for Scientific Research (B)
财政年份：
2002
资助国家：
日本
起止时间：
2002 至 2004
项目状态：
已结题

项目摘要

The micro surface topography is known empirically to affect on biological functions. Therefore, commercial Titanium implants are treated to cover on the surface with various kinds of topography, so called as micro texture.Here, two procedures of forming micro texture are discussed ; direct groove cutting of Titanium alloy with diamond tools, and multi roll forming for regular grooves. The former is used to optimize the micro texture design for some surface functions, and the later aims to forming the above-mentioned optimal micro texture on Titanium implants for individual body.Fly cutting and shaping processes using diamond tools are discussed on direct cutting of Titanium alloy.Titanium is easy to paste on the rake face of diamond tools to deteriorate groove geometry or generating burr, on groove shoulders. The model of the burr generating mechanism on groove shoulders is proposed in order to decrease the burr. According to the model, tensile force works on groove shoulders to make burr when uncut chip thickness is large. Therefore, burr can be depressed by decreasing uncut chip thickness, for instance less than 1μm.Furthermore, roll forming on Titanium is also discussed for applying to economical micro texturing on 3D surface. A flexible tool holder capable to follow an arbitrary geometry is proposed. Micro rollers held on the flexible tool holder form multi grooves at a constant pressure. Here, grooving characteristics are estimated using sintered tungsten carbide micro rollers, which are φ0.4mm in OD, 60゜ in top angle. The sharpness on the top edge of a roller is dominant for multi micro grooving. The sharpness of 1-2 μm accuracy is achieved after optimal grinding conditions using a diamond grinding wheel. As a result, a few micron grooving on a 3D surface is possible using a developed tool.

根据经验，已知微表面形貌影响生物功能。因此，商品化钛植入体表面经过处理，形成各种形貌的微织构，本文讨论了两种微织构的形成方法：用金刚石工具直接切槽钛合金和多辊成形规则槽。前者用于优化某些表面功能的微观织构设计，后者用于在钛合金植入物上形成上述针对个体的最佳微观织构。讨论了使用金刚石工具直接切削钛合金的飞切和成形工艺。钛容易粘附在金刚石工具的前刀面上，从而破坏沟槽几何形状或在沟槽肩部产生毛刺。为了减少毛刺的产生，提出了槽肩毛刺产生机理的数学模型。根据该模型，当未切屑厚度较大时，拉力作用在槽肩上，产生毛刺。因此，可以通过减小未切屑厚度（例如小于1μm）来抑制毛刺。此外，还讨论了钛合金辊轧成形在3D表面上经济微织构化的应用。提出了一种能够遵循任意几何形状的柔性工具保持器。保持在柔性工具保持器上的微辊在恒定压力下形成多个凹槽。在这里，使用外径为φ0.4mm，顶角为60 °的烧结碳化钨微辊来评估开槽特性。在多微槽加工中，轧辊上边缘的锋利度是主要的。在使用金刚石砂轮的最佳磨削条件下，可实现1-2 μm精度的锐度。因此，使用开发的工具可以在3D表面上进行几微米的开槽。