Cooperative Research on Precision Machining

在我们的剪切（延性）模式磨削实验结果中，有两个严重的问题阻碍了它的发展。一是砂轮与工件的接触面积限制了去除率，这可能会产生热量。在实验过程中，在研磨表面上出现了由燃烧引起的裂纹;剪切模式研磨是不可能的。从这个结果，我们猜测，一个大的接触面积限制了冷却剂的感应，并促进高温的冷却剂区产生热量。在某些类型的磨削几何形状中，难以避免大的接触面积。因此，我们已经提出了一种替代方案是在超声频率下激励砂轮，这也允许砂轮和工件之间的冷却剂，结果表明，磨削力值低于在剪切模式下无振动（常规）磨削获得的值。另外，通过对砂轮进行激振，在砂轮接触区引入冷却液，可以使磨削速度提高2倍，另一个原因是砂轮表面的各种磨粒对被磨削表面产生了划痕。因此，很难保持高质量的磨削表面，因为使用砂轮不可能使磨粒的尺寸、形状、密度和取向均匀。因此，我们得出的结论是，我们需要一种新的金刚石工具，而不是砂轮。它是“工程工具”。这种工具在单晶金刚石表面上有许多小柱子（1，0，0）。钻石尺寸为2*2* 1 mm。使用准分子激光器对这些立柱进行精确加工，彼此相距15 g。每根柱子尺寸为5亩见方，10亩高。这代表了具有恒定和已知间距的活性金刚石的非常高的密度。我们期待。与传统加工相比，“工程刀具”技术有助于发展硬脆材料的高精度加工。

In our experimental results of shear(ductile) mode grinding, there are two serious problems as obstacles to its development. One is that the removal rate is limited by the contact area of wheel to workpiece which might cause heat generation. During the experiment, cracks caused by burning appeared on the ground surface ; shear mode grinding was impossible. From this result, we guessed that a large contact area limits the induction of coolant and promotes high temperatures in the coolant zone where heat is generated. In some types of grinding geometry a large contact area is difficult to avoid. Therefore, we already suggested that an alternative is to excite the wheel at ultrasonic frequency, which also admits coolant between wheel and workpiece, The results showed that the grinding force value was lower than that obtained with no vibration (conventional) grinding in shear mode. Further, exciting the wheel to induce a coolant in the contact zone, it was found possible that removal rate is increased 2 times.Another is that the ground surface is scratched by various abrasive grits on the grinding wheel surface. Therefore, it is very difficult to keep a high quality ground surface, because, it is impossible to uniform the grits size, form, density, and orientation, using the grinding wheel. Thus, we were led to the conclusion that we need a new diamond tool instead of the grinding wheel. It is "Engineered Tool" . This tool has many small posts on the single crystal diamond surface (1,0,0). The diamond size is 2*2*1mm. Those posts was precisely machined 15 g in apart from each other, using Excimer Laser. Each post size is 5 mu m square, 10 mu m height. This represents a very high density of active diamond with constant and known spacing. We expect. that the "Engineered Tool" technique contrivutes to the development of high precision machining of hard and brittle materials, as contrasted with conventional machining.