令天已经进入了超高压、超高温、超高速的时代。大家知道,火箭不仅是强有力的军事武器,而且是宇宙飞行的必要工具。现在洲际弹道火箭的速度最快的达到了每秒7公里,发射人造卫星的火箭速度达到了每秒8公里,而为了飞到地球以外去,速度要达到每秒11.2公里。要达到这样高的速度需要特殊的燃料,燃烧室的温度很高,就不是一般飞机上的发动机所能够胜任的。这就要求有一种既像钢铁一般坚硬、又像陶瓷一般耐高温的材料。“金属陶瓷”就可以满足这样的要求。在日常生活里我们早就有过这样的经验:水泥中加入一些钢筋可以增加强度。科学家们在氧化铝中加入一些金属鉻,在碳化釱中加入一些金属镍,它们便具有 The day has entered the era of ultra-high pressure, ultra-high temperature and ultra-high speed. As we all know, the rocket is not only a powerful military weapon but also an essential tool for space flight. At present, the intercontinental ballistic rocket has achieved the fastest speed of 7 kilometers per second. The rocket that launches the satellite has reached a speed of 8 kilometers per second. In order to fly outside the earth, the speed is 11.2 kilometers per second. To achieve such a high speed requires special fuel, and the temperature of the combustion chamber is high, which is not enough for an ordinary aircraft engine. This requires a material that is both as hard as steel and high in temperature like ceramics. “Ceramic” can meet this requirement. In our daily lives we have long had this experience: adding some steel reinforcement to cement can increase the strength. The scientists added some metallic chromium to the alumina and added some metallic nickel to the tantalum carbide. They have