Investigation on forming process of micro texture surfaces and evaluation of their surface function

根据成形或加工过程，大多数表面功能都是在零件表面上实现的，这些表面由微观随机表面组成，并以统计方式表示。因此，函数曲面的优化设计是非常困难的。本文讨论了具有均匀沟槽或凹坑的归一化微织构表面的亚微米成形过程，并将其与表面功能进行了关联。(1)亚微米抛光切槽：槽肩毛刺尺寸和槽底半径可由工件材料控制。另一方面，摩擦速度或工件和抛光工具之间的界面上的摩擦对它们是不敏感的。(2)使用压头的亚微米凹坑成形：凹坑肩部上的毛刺或下垂与工件和压头之间的界面上的摩擦密切相关。对于有色金属，凹坑的体积近似地被去除到凹坑肩部上的毛刺的体积，但是对于玻璃，压头下的材料被塑性地压缩。(3)光刻盘的制作与评价：采用光刻工艺，初步制作了尺寸为3 μm、高度为30nm的均匀盘区的标准化磁盘。加载在磁头上的摩擦力沿着滑动时间在磁盘上显著增加，这不是因为平台的顶表面上的磨损，而是因为平台的下沉。下沉是由于磁头反复加载而产生的疲劳引起的。摩擦力的增加可以通过优化焊盘的偏置和在盘基片上应用更硬的材料如玻璃来抑制。

According to forming or machining process, most of surface functions are realized on the surfaces of components, which consist of microscopically random surfaces and are represented statistically. Therefore, the optimal design of function surfaces is significantly difficult. Here, sub-micron forming process for normalized micro texture surfaces covered with uniform grooves or dimples were discussed, and correlated with surface functions.As the results, the followings were verified.(1) Sub-micron grooving with burnishing tool : Dimensions of burr on a groove shoulder and radius on a groove bottom are controllable by work material. On the other hand, rubbing speed or friction on the interface between a workpiece and a burnishing tool is insensible to them.(2) Sub-micron dimple forming using indentor : Burr or droop on a dimple shoulder strongly correlated with friction on the interface between a workpiece and a indentor. The volume of dimples is approximately removed to the volume of burr on a dimple shoulder for non-ferrous metals, but the material under a indentor is condensed plastically for glass.(3) Forming and evaluation of photo lithography disk : Normalized magnetic disks covered with uniformed land of 3 μm in dimater and 30 nm in height were made tentatively on photo lithography process. Friction force loading on a magnetic head substantially increases on the disks along with sliding time, because not of wear on top surfaces of lands but of the subsidence of lands. The subsidence is caused by fatigue with repeated loaded from a magnetic head. The increase of friction force could be suppressed by optimizing the destribution of lands and applying harder material like glass to disk substrates.