Conventionally, the sharpening of the cutting edges of hard and brittle tools made of diamond and other materials has been achieved by skif polishing, in which diamond is used to cut diamond, or by "point laser processing," in which a laser is focused on the cutting edge. However, there has been a demand for further improvement in the edge forming accuracy and surface roughness at the submicron level for these methods of cutting edge formation.

Example of skiff polishing

Examples of conventional laser processing

1.2 PLG (Pulse Laser Grinding) Technology

By focusing a short-pulse laser beam with a long focal length lens and making it almost parallel to the machining surface, we have achieved ultra-precise and rapid sharpening of the cutting edges of hard and brittle cutting tools. It is possible to sharpen the cutting edges of diamond-coated tools and sintered tools such as cBN and PCD to submicron roundness. Diamond-coated tools in particular require a short time to mold, making it possible to provide tools with high-precision cutting edges required for precision/fine cutting at low cost. These tools are used for high-precision machining of hard materials such as mold materials.

(Patent application 2015-38888, SUPPORT, Aichi Knowledge Hub Project, etc., Professor Fumihiro Itoigawa, Nagoya Institute of Technology)
Daisuke Suzuki, Keiichi Kawata, Fumihiro Itoigawa, Takashi Nakamura, "Shape Creation of Superabrasive Sintered Tool Materials Using Nanosecond Pulse Laser," Proceedings of the 2010 Japan Society for Precision Engineering Autumn Meeting, pp.277-278, E09
・Daisuke Suzuki, Fumihiro Itoigawa, Keiichi Kawata, Shingo Ono, Takashi Nakamura, Kazuhisa Miyazaki, "Development of a cutting tool blade sharpening method using an ultrashort pulse laser," Proceedings of the 2012 Japan Society for Precision Engineering Autumn Meeting, pp.203-204, C18
・Hideya Kodama, Keiichi Kawata, Kazumasa Ishikawa, Fumihiro Itoigawa, "High-efficiency machining of cemented carbide using diamond-coated tools with cutting edge shaped by pulsed laser," Proceedings of the 2016 Japan Society for Precision Engineering Autumn Meeting, pp.587-588, K63

Image of cylindrical processing area and PLG processing

1.3 Examples of machining using PLG diamond tools

Sharpening the cutting edge of diamond-coated tools

Low-cost mirror-finish machining of mold steel achieved by combining ultrasonic elliptical vibration cutting

2. PLG of sintered cBN tools

2.1 Features of the developed technology

Increased hardness regardless of binder and cBN particle size ⇔ Reduced surface defects (cracks)

Erosion resistance test by sandblasting

2.2 Machining examples using PLG cBN sintered tools

■ Properties of the workpiece

■ Ultra-high speed machining of gray cast iron

Daisuke Suzuki, Fumihiro Itoigawa, Takashi Nakamura, Keiichi Kawata, Tetsuro Suganuma, "Research on grinding-less finishing of hardened steel by precision cutting using PcBN tools," Proceedings of the 2011 Japan Society for Precision Engineering Autumn Meeting, pp.235-236, G24
Daisuke Suzuki, Fumihiro Itoigawa, Takashi Nakamura, Keiichi Kawata, Tetsuro Suganuma, "Performance evaluation of PcBN cutting tools for pulsed laser finishing in cutting hardened steel," Proceedings of the 2012 Japan Society for Precision Engineering Spring Meeting, pp.235-236, C37
・Atsushi Kimura, Fumihiro Itoigawa, Takashi Nakamura, "Surface quality and cutting performance of cBN tools formed by short pulse laser", Proceedings of the 2017 Japan Society for Precision Engineering Autumn Meeting, pp.121-122, B33

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