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Composite Materials
1. Among the oldest and newest of structural materials are composite materials. It was discovered many years ago that two or more materials could be used together as one. Later it was proved that such a combination often behaved better than each material alone. Following this principle, clay and straw were combined to make bricks. For centuries composite materials remained virtually untapped. Only then monolithic materials, such as iron, copper were served for needs of an advancing technology. Recently it was a development of technology with coming of reinforced concrete, linoleum, plasterboard and plywood panels.
2. During the 1930s and 1940s light-weight honeycomb structures, machine parts made from compressed metal powders and plastic reinforced with glass fibers became commercial realities. These developments marked the beginning of the modern era of composite engineering materials. It was mentioned growing and using composite materials. Nevertheless, the emergence of a strict discipline and technology of composite materials is barely 20 years old.
3. There are two major reasons for the current interest in composite materials. The first is the demand for materials that will outperform the traditional monolithic materials. The second and more important in the long run, is that composites offer engineers the opportunity to design totally new materials, with the precise combination of properties needed for a specific task. Although new composites are usually more costly than conventional materials, they can be used more sparingly, because of their superior qualities.
Ответьте на вопрос:
What are characteristics of composite materials?
They are economy in use, superior qualities and combination of rare properties.
They are economy in use, lower qualities and combination of needed properties.
They are high cost, lower qualities and combination of necessary properties.
They are economy in use, superior qualities and combination of necessary properties.