| Project/Area Number |
60460085
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| Research Category |
Grant-in-Aid for General Scientific Research (B)
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| Allocation Type | Single-year Grants |
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| Research Field |
機械工作
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| Research Institution | Kitami Institute of technology |
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Principal Investigator |
KITAGAWA Takeaki Professor, Department of Mechanical Engineering, Kitami Institute of Technology, 工学部, 教授 (40003165)
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| Co-Investigator(Kenkyū-buntansha) |
FUTAMATA Masami Assoc. Professor, Department of Mechanical Engineering, Kitami Institute of Tech, 工学部, 助教授 (60003191)
MAEKAWA Katsuhiro Assoc. Professor, Department of Mechanical Engineering, Kitami Institute of Tech, 工学部, 助教授 (20126329)
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| Project Period (FY) |
1985 – 1986
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| Project Status |
Completed (Fiscal Year 1986)
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| Budget Amount *help |
¥7,500,000 (Direct Cost: ¥7,500,000)
Fiscal Year 1986: ¥6,000,000 (Direct Cost: ¥6,000,000)
Fiscal Year 1985: ¥1,500,000 (Direct Cost: ¥1,500,000)
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| Keywords | Hot machining / Plasma arc / jet heating / Difficult-to-cut material / High manganese steel / Chilled cast iron / Inorganic ceramics / Machinability |
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| Research Abstract |
A new hot machining technique using plasma arc/jet heating has been developed in the first year of the project to improve the machinability of high hardness and/or brittle materials. Material just after being heated and made locally soft is removed by cutting tools. The hot machining of 18%Mn steel and 2.25%Cr cast iron showed a remarkable drop of the cutting forces compared to normal turning, and also prolonged tool life and the prevention of chatter, which leads to good integrity of the machined surface.
Simulation analysis in conjunction with the measured flow characteristics of 18%Mn steel has also successfully been conducted to reproduce the experimental results, clarifying the mechanism of the machinability improvement by the plasma hot machining. Eventually, the numerical method developed here will be employed to predict the optimal heating conditions.
The second year concentrated our attention on the application of the hot machining to the effective removal of inorganic ceramics, such as alumina, zirconia, Pyrex, mullite and silicon nitride. Although oxide ceramics like alumina and zirconia had a tendency to fracture due to thermal stress, the cutting forces, particularly the thrust force, were drastically decreased at the high heating temperatures, e.g.above 1,050 ゜C in the case of silicon nitride. Further the discontinuous chips produced in the normal cutting became continuous with increasing the heating temperature, accompanied by better surface quality and less flaws. Tool wear was found to be decreased by the hot machining to 1/8 of its value in normal machining in the case of turning silicon nitride with a diamond tool. Besides the fragile surface layer pre-produced by the plasma jet heating with a thermal cycle was removed under normal cutting conditions. In the case of turning Pyrex, the wear of a carbide tool was meaningfully decreased.
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