Metals are materials most widely us

Metals are materials most widely used in industry because of their properties. The study of the production and properties of metals is known as metallurgy. The separation between the atoms in metals is small, so most metals are dense. The atoms are arranged regularly and сan slide over each other. That is why metals are malleable (can be deformed and bent without fracture) and ductile (can be drawn into wire). Metals vary greatly in their properties. For example, lead is soft and can be bent by hand, while iron can only be worked by hammering at red heat. The regular arrangement of atoms in metals gives them a crystalline structure, irregular crystals are called grains. The properties of the metals depend on the size, shape, orientation, and composition of these grains. In general, a metal with small grains will be harder and stronger than one with coarse grains. Heat treatment such as quenching, tempering, or annealing controls the nature of the grains and their size in the metal. Small amounts of other metals (less than 1 per cent) are often added to a pure metal. This is called alloying (легирование) and it changes the grain structure and properties of metals. All metals can be formed by drawing, rolling, hammering and extrusion, but some require hot-working. Металлы являются предметом усталость металла и вызывая деформации ползучести (медленноувеличивать длина под нагрузкой) и неудачи. Обе эффекты учитываются инженерами при проектировании, например, самолеты, Турбины газовые и сосуды под давлением для высокотемпературных химических процессов. Металлы могут быть разработаны с помощью станков например токарные, фрезерные машины, формирователь и мясорубки. Способы обработки металла зависит от его свойств. Многие металлы могут быть твореное и литье в формы, но необходимы специальные условия для металлов, которые реагируют с воздухом.