Ultra-precision diamond cutting tool is one of the key elements to achieve ultra- mold finishing . This paper produced in Japan AlliedDiamond Corporation UPC (UltraPrecisionCuttingTool) ultra precision diamond cutting tool performance , while ultra- fine cutting different workpiece materials and processing instances of tool wear condition to make a presentation .

Performance 1.UPC ultra-precision diamond tools

Single crystal diamond having a cubic crystal structure between carbon atoms covalently firmly bonded with the lattice constant of 3.567 angstroms , the interatomic distance of a combination of 1.544 angstroms . Because the characteristics of single crystal diamond atomic structure , the material can be used as tool to get other materials do not have excellent hardness and smooth , sharp cutting edge . UPC ultra-precision diamond tools were prepared using ultra- fine grinding , can maximize the material properties , to obtain a smooth and abrasion resistance both sharp cutting edge , and super- finishing machine matched to achieve high-precision aspheric shape and fine shape super finishing.

To meet the requirements of the mold super finishing , cutting depth should be set within the nanometer range . To this end, the cutting tool requirements : ① sharp nose radius R reaches the level of tens of nanometers ; smoothness ② cutting edge ridge to reach the nanoscale level . When using the nose radius of the same size cut deep processing, easy to damage the workpiece face , smooth processing, chip flow, cutting thickness variation due to the elastic deformation of the workpiece is also very small , can achieve super finishing .

2.UPC tooling wear state of the workpiece material differences

Thermochemical diamond tool wear condition varies greatly according to the type of material being different processing . After using a sharp knife in ultra-precision lathe 130 ° straight cutting edge ultra-precision diamond turning of oxygen-free copper and aluminum conduct face turning , wear state of the tool tip shows that the tool flank before cutting oxygen-free copper produced crater wear , but still maintain a sharp cutting edge ridge state ; cutting aluminum ridge wear of the cutting edge becomes circular blade , but did not find the rake face crater wear . From the state of wear of these differences can be seen in different wear mechanisms : cutting copper when the tool rake face crater wear is due to produce catalytic role of copper -induced oxidation of the diamond , but because of the cutting edge and the workpiece ridge when cutting aluminum , as a result of direct contact with the surface of the surface to form aluminum carbide tool , the cutting edge of the workpiece material is excised leaving the cutting edges wear, extended wear but the cutting direction of the copper ; no gap in full contact wear without oxidation Instead ( back from the cutting edge flank extension ) , it will not produce the rake face crater wear .

Due to the different thermal and chemical phenomena of different workpiece material , tool wear state is different , and therefore should be based on different types of workpiece materials to design a reasonable rake angle and the angle .

3.UPC-R examples of ultra-precision diamond cutting tools

UPC-R is a circular cutting edge of UPC using ultra-precision diamond cutting tools , and its use is typically used for DVD and other super finishing aspherical mold. Contour accuracy UPC-R tool circular cutting edge is less than 50nm, is currently the world's highest precision ; arc R only 5μm, is also the world's smallest . Use UPC-R ultra-precision diamond cutting tools mold aspherical on both coordinates ultra-precision machine tool CNC machining highlights include : ① how to form a thin continuous stable and smooth chip discharge ; ② workpiece rotation should have a high level of balancing performance ; ③ workpiece can be accurately centered ; ④ stable supply of cutting fluid and the like. Since heat causes a chemical reaction when the diamond graphite machining of steel workpiece to the diffusion , and therefore not suitable for UPC diamond tool steel mold super finishing . However, if the surface of the steel mold with a non- electrolytic plating method of tens of microns to several hundred microns thick nickel plating layer , the diamond tool used for super finishing UPC . About coating quality , you should choose no holes, segregation and other defects in the crystalline structure of amorphous coating.

4.UPC-T Examples of ultra-precision diamond cutting tools

UPC-T is a triangular cutting edge UPC ultra-precision diamond cutting tools, dies and is mainly used for liquid crystal Fresnel lens , such as a diffraction grating light guide plate mold super finishing .

In recent years, high-precision , miniaturization and integration of optical components rapid development , from a non- spherical lens to be able to achieve a thin lightweight, integrated Fresnel lens , super finishing techniques have become increasingly demanding . The machining mode is a UPC-T Examples of the aspherical shape and ultra -precision diamond cutter grating portion ultra fine finish , thus requiring a cutting edge tool edge R <100nm and excellent cutting performance. UPC-T for the tip of the cutting edge of the cutting edge 50nm small , super finishing can be achieved .

Tooling mold has been developed as an indispensable lens mold processing method using ultra- fine diamond . In the future, along with the improvement of quality molds and molded parts for high- precision, multi-functional rising market demand , and the growth of medical and biological fields tooling needs , will continue to promote the development of new tools.