SAKAMOTO Haruhisa Sophia Univ., Dept.of Mech.Eng., Assistant, 理工学部, 助手 (40276514)
SHIMIZU Shinji Sophia Univ., Dept.of Mech.Eng., Professor, 理工学部, 教授 (70146801)
MORONUKI Nobuyuki Tokyo Metro.Univ., Dept.of Prec.Eng., Assoc.Prof., 工学部, 助教授 (90166463)
FURUKAWA Yuji Tokyo Metro.Univ., Dept.of Prec.Eng.Professor, 工学部, 教授 (10087190)
MORITA Noboru Chiba Univ., Dept.of Mech.Eng., Assoc.Prof., 工学部, 助教授 (30239660)
|Budget Amount *help
¥13,100,000 (Direct Cost: ¥13,100,000)
Fiscal Year 1998: ¥1,300,000 (Direct Cost: ¥1,300,000)
Fiscal Year 1997: ¥1,400,000 (Direct Cost: ¥1,400,000)
Fiscal Year 1996: ¥10,400,000 (Direct Cost: ¥10,400,000)
The low energy electron, which is called exoelectron with less energy than usual work function, is radiated during and after machining materials surface. It is known that this phenomenon is sensitive to changes of crystal structure of material surface. This report describes the results of examining the possibility of photo stimulated exoelectron emission as a method of the process monitoring and measuring of a subsurface damage. As a result of cutting experiment in vacuum atmosphere, it is confirmed that exoelectron emission is observed during the deformation of materials and that there is a relationship between cutting conditions and the emission intensity and energy distribution, These results show the possibility of exoelectron emission for new monitoring method of process and subsurface damage.
Contact mechanism in vacuum was investigated from a viewpoint of contact deformation and friction. Experiments were performed both on macroscopic scale model and microscopic scale model. From
the macro-model, it was found that the contact deformation in vacuum (1.3^*10^<-6>@Pa) becomes larger than that in atmosphere. The reason for this difference is considered to be the spring effect of the enclosed air at the interface. The spring property is approximated as a traditional nonlinear spring formula based on the experimental results. Applying this relationship, an analytical model was constructed, by which displacement of a slider due to contact deformation, both in lateral and angular direction, can be estimated quantitatively, In the micro-model experiments, a micro-linear slider system was produced by anisotropic etching. Both the slider and guide are made of silicon. Typical size of the slider is 327um in width, 515um in length, and 450um in height. The frictional property in vacuum was investigated in a scanning electron microscope. The motion is given by precise inchworm micro-stage. The results show that the friction in vacuum becomes smaller than that in atmosphere. The difference becomes large when the apparent contact area is large The reasons are considered to be the meniscus effect.
The evaluation system of the contact pressure distribution in the joint was constructed. The contact pressure distribution can be measured based on the echo height of the ultrasonic pulse incident on the joint surface. In this research, the correction method was established in the nonlinear relationship between the load and the real contact area, resulting from low or high pressure. By using this system, the influence of the joint condition on the contact behavior was evaluated, and the following results were obtained. 1) The smaller the surface roughness is, the larger an increase in the real contact area to the load is, and the contact pressure distribution becomes more uniform. 2) When the loads act on the joint repeatedly without separating the joint, the real contact areas grow wider than in the last time loading, and come to be constant after several loading. In this case, the contact pressure distribution becomes more uniform than in the first time. 3) When the joint is separated after loading, the contact behavior above-mentioned 2) does not occur even if the loads act repeatedly. In this case, the previous joint condition hardly exerts the influence on the current contact behavior. Less