High temperature fatigue characteristics of P/M and hot-forged W-Re and TZM for X-ray target of CT scanner

The fatigue strengths at 1000 °C of layered W-Re/TZM, bulk W-Re and bulk TZM for x-ray target materials were successfully evaluated under load-controlled four-point bending by introducing a fatigue failure criterion as twotimes increase of initial compliance. The obtained fatigue strengths at 1000 °C for layered W-Re/TZM and bulk WRe were similar and 280 MPa and 290 MPa at 106 cycles, respectively, while that of bulk TZM was 200 MPa. During fatigue loading at 1000 °C, dominant fatigue damage would be multiple intergranular crack nucleation and propagation, which would induce the increase of compliance. The reasonability of the fatigue failure criterion was confirmed by the fatigue process observations and the results of room temperature fatigue tests of the specimens tested at 1000 °C up to the cycles corresponding to the fatigue failure criterion

Fundamental Characteristics of a Cylindrical Linear Pulse Motor for the Artificial Heart

A new actuator using a cylindrical linear pulse motor for the artificial heart is proposed with descriptions of the principle of operation, theoretical expression of thrust, and experimental results. The actuator has a simple configuration and its size is much smaller than the ordinary external backup facility using a pneumatic power. The actuator consists chiefly of a linear pulse motor and two rooms of sacs for the right and left ventricles. Some problems have been found to be solved before the actuator can be applied to the actual artificial heart.Article信州大学工学部紀要 56: 59-72 (1984)departmental bulletin pape