Toughness problems in advanced materials

Toughness is the most important characteristic of structural materials and is widely measured using the Charpy impact test, which was developed at the beginning of twentieth century by the Frenchman Charpy. The author has successfully developed a new dynamic fracture toughness testing and evaluation system using the instrumented Charpy impact test. The new system is called the 'CAI system'. This paper introduces the CAI system. Many advanced materials have been developed since 1980. Apart from cost performance, the most important problem with new materials is in their low fracture toughness. The toughness problems of various advanced structural materials such as ceramics, intermetallics, Al–Li–alloys, Ti alloys, metal matrix composites and austempered ductile iron (ADI) are reviewed based on the author's research.