The compressive-type quasi-fatigue fracture of vacuum-evaporated gold films was observed in a scanning electron microscope and a transmission electron microscope by mounting the film on an uniblock substrate. The gold films in a thickness range 620 to 3500 Å were strained to fracture in cyclic compression in the as-evaporated condition and after heated at different temperatures. The fatigue tests were conducted at a strain range of 0.3 to 0.6%. Quasi-fatigue fracture under cyclic compressive-type strain resulted in the formation of dimples which were generally bounded by a lip. The crack propagation occurred along oval-shaped dimple depressions that were a direct results of the microdimple coalescence. Fracture life for heated films indicated a sharp rise below 400°C. The total cycles up to fracture was usually of the order of 10 to 500 cycles.

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The theory of a friction vacuum gauge using a tuning-fork-shaped quartz oscillator is presented. The dependences of electric impedance and resonance frequency of the quartz oscillator on gas pressure are theoretically analyzed on the basis of “a string-of-beads” model for the quartz oscillator. It is shown that the impedance change results from the velocity term of the drag acting on an oscillator, while the resonance frequency shift results from the acceleration term of the drag. The drag is calculated by means of the kinetic theory of gases in lower pressure (molecular flow) region, and by means of fluid mechanics in higher pressure (viscous flow) region. These theoretical results are found to be in quantitative agreement with experimental results. In particular, it is shown that the increase of impedance in the neighborhood of atmospheric pressure results from the small vibration of fluid (surrounding gas) rather than turbulent flow or the emission of sound. Also, theoretical predictions about the dependences of impedance and resonance frequency on gas species are experimentally verified.
Furthermore, the pressure dependence of the impedance in intermediate pressure region is formulated by taking into account a “slip” effect of gas molecules at the surface of an object. By the formal extension of this formula to molecular flow region, a single formula describing the pressure dependence of the impedance over the whole pressure region is obtained. This formula is found to be in numerical agreement with experimental data.

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Ion emission properties of molten metals were measured. Samples were heated with a tungsten filament. The accelerating voltages were applied between the tungsten filament and the ground potential. Sample metals used were Mg, Al, Fe, Cu and Au. It is shown that molten Mg and Al emit their own ions in addition to the impurity ions of Na and K included in the tungsten filament while the other samples do not emit their own ions. The energy analysis shows that these ions are formed on the molten sample surface or the neighbourhood. The dependence of ion formation on the difference of the work function of sample from that of W is discussed.

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