Masao Murakawa, Hiroyuki
Noguchi and Masahiko Jin
Nippon Institute of
Technology
4-1 Gakuendai,
Miyashiro-machi, Minamisaitama-gun,Saitama-ken 345-8501, Japan
E-mail Address: mura@nit.ac.jp
Fax: 81-480-33-7645
Phone: 81-480-33-7618
Diamond is known to be the hardest material
on earth. Thus, it shows a superb anti-wear capability when used as the tool
material for cutting almost all the work materials except ferrous ones. This is
because diamond can be decomposed and absorbed very easily into the ferrous
materials because of the involved cutting heat generation caused when diamond
contacts with ferrous work materials.
To solve this problem we have attempted to
utilize the effects of ultrasonic vibration added vertically onto the rotating
shaft of end milling tool so as to increase the lubricity and/or cooling
capability for the diamond tool thereby reducing the involved temperature over
the rake face of the tool cutting edge. By this means it was amazingly found
that life of sintered diamond end mill used to cut hard ferrous die materials
could endure more than ten times that of the sintered carbide tool coated with
TiAlN which is believed to be the best coating material at present to deal with
hard ferrous work materials.
This result had been somehow anticipated even
from the more fundamental tribological test wherein various uncoated and coated
sintered carbide balls were made to contact with the stainless steel plate
specimen and subjected to vertical load with or without ultrasonic vibration.
The results showed that with the addition of very light and environment
friendly lubricant the balls with ultrasonic vibration kept a very low and
stable value of frictional coefficient against stainless steel plate specimen
and substantially no ball wear at all as well after two hours of test using a
newly built ultrasonic tribometer.
Keywords:
Diamond, End mill tool, Ultrasonic vibration, TiAlN coating, Ultrasonic
tribometer