| 摘要 |
<p>Appts. for determining the size(S) of, and the distance(D) between, Si crystals in Al-Si alloys, includes a probe with a sharp point which is pressed against the surface being tested by a prescribed force obtd. from its spring mounting. The probe is also driven along the surface at a constant speed, and is connected in an electric circuit with a voltmeter showing a voltage while the probe travels over Al, but the voltage drops to ca. zero during its travel over a Si crystal. The pref. appts. consists of a housing fitted with feet resting on the test piece, and an electric-, mechanical-, pneumatic-, or hydraulic- drive moves the probe carrier via a toothed rack. The voltage in the circuit which includes both the probe and the test piece is indicated and/or recorded e.g. via an oscilloscope.</p> |
