''Here are the beginnings of fire and engineering, the origins of pyrotechnology, and the bridge to more recent ceramic and metal technology,'' said Mr Brown.
“这是火和工程的开端，古代高温技术的源头，更晚的陶瓷、金属技术的桥梁。”布朗说。
3
Engineeringceramic materials are difficult to machine because of their outstanding properties, such as high hardness, high wear resistance, high erosion resistance and high brittleness.