| 摘要 |
PURPOSE:To obtain a diaphragm with excellent characteristic, by prepairing a diaphragm whose main component is a sintering substance of aluminum boride, or a sintering substance of mixing crystal of aluminum boride and magnesium boride. CONSTITUTION:A diaphragm of the acoustic transducer is prepared by a sintering substance of aluminum boride, or a sintering substance consisting of mixing crystal of aluminum boride and magnesium boride. AlB12 has an excellent characteristic as a material for the diaphragm since its density is 1.82g/cm<3>, and the speed of sound is approx. 12,900m/second. As for AlB2, it's density is 2.95g/cm<3> speed is approx. 12,000m/second, and it has a suitable characteristic for a material for the diaphragm. On the other hand, as for a mixing crystal compound of magnesium boride and aluminum boride, the sound velocity is distributed in 12,000-12,500 m/second, and the density is in 2.95-2.4. Although it is almost same as AlB2, etc., its density can be made small comparing with AlB2. This fact is very advantageous to design a diaphragm. Accordingly, a diaphragm with excellent characteristic is obtained by using these sintering substances. |
