Bronze: history and use
Bronze (Fren. bronze, from Ital. - bronzo), an alloy of copper with different chemical elements, mainly metals, such as tin, aluminum, beryllium, lead, cadmium, chromium, and others. Bronze is called pewter, aluminum, beryllium, etc. Bronze is not referred to as copper-zinc (Brass) and Nickel (Nickel-Copper alloys).
Tin Bronze is an ancient alloy produced by man. The first Bronze was obtained 3 thousand years BC by regenerative melting a mixture of copper and tin ores with charcoal. Much later, Bronze was made by adding copper, tin and other metals.
Bronze was used in ancient times for the production of weapons and tools (arrowheads, daggers, axes), jewelry, coins and mirrors. In the middle ages a large number of Bronze was cast bells. Bronze for bells typically contains 20% of tin. Until the mid-19th century for casting gun barrels was used so-called gun Bronze, an alloy of copper and 10% of tin. In the 19th century they began to use Bronze in engineering (sleeve bearings, valve steam machines, gears, valves). Especially valuable for engineering was antifriction properties and corrosion resistance of tin Bronze. In industrialized countries, a large number of brands of machine Bronze of different composition, containing 10-15% of tin, up to 5-10% of zinc, and small additions of lead and phosphorus.
In the 20th century substitutes for tin Bronze began to produce, without deficient tin and, therefore, often superior to its many properties. The most common aluminum Bronze with 5% to 12% of aluminum and additions of Iron, Manganese and Nickel. In the 20-30-ies tin-free Bronze (beryllium, nickel-silicon and others) was developed. They are able to gain strength during hardening with subsequent artificial aging (Heat treatment). For example, an alloy of copper with 2% of beryllium after the heat treatment takes more strength than much steel and high yield strength: 1280 Mn/m2 (128 kgf/mm2).
Various kinds of Bronze play an important role in modern engineering, aviation and rocket technology, shipbuilding and other industries.
The use of tin bronze depends on the type of alloy, which is represented on the market in two versions: wrought and foundry.
Wrought Bronze is used, typically, for the manufacture of a wide range of springs, bearings, bushings, couplings and other parts that need the presence of high anti-friction properties. Foundry bronze alloy is ideally suited for the production of valves, bearings, gears and other critical parts , the operation of which requires wear resistance and durability.
New technologies have initiated the production of a wide range of tinless bronze alloys, in which instead of the tin as the main alloying component, other chemical elements are used: Aluminum, Manganese, Nickel, Iron, Lead. The resulting innovative solutions for bronze are high corrosion resistance and density that allows the use of these alloys for solving the following tasks:
industrial production of bronze rolled sheet, wire, rod and tube;
the production of components for the manufacture of chemical apparatus;
manufacturer of control valves for pipes and heating systems;
the production of luxury jewelry and sanitary ware;
the decoration of prestigious interiors.
When in the bronze alloy beryllium is added, improves weldability and increased mechanical properties of the metal, which is a significant factor in the expansion of the scope of this plastic material.
Despite its relatively high cost, bronze is in great demand every year in various projects and production. Expressive appearance of bronze is successfully complemented by high performance plasticity, ductility, resistance to corrosion, wear resistance. Without a doubt, Bronze is long lasting. For example, the profitability of the pipeline, with the most important places in bronze pipe and other fittings, is characterized by the highest rates. Thus, the production of bronze will develop in the future, offering consumers all the higher qualities of this wonderful colored alloy, which has come down to us through the ages.
Bronze is the first in the history alloy of metals, which gave its name to a whole era of mankind. Its name derives from the name of an ancient Italian seaport Brindisi. In the 4 BC brought merchants copper and tin. Local masters mastered the mass production of alloy of these two metals. Flowering bronze received in Ancient Rome and Ancient Greece, where it was cast by the giant statues of gods and heroes. Actively Bronze was used for the manufacture of household items, decorations, tableware. During Renaissance, interest in the bronze broke out in Europe, they made copies of ancient statues, church and household utensils, furniture, weapons and bells. Bronze always lived side by side with natural stone as it goes perfectly with the marble, serpentine, jasper, obsidian, and other gemstones. Especially gilded bronze is beautiful when stands next to green malachite. Patina, greenish or brown plaque, which appears as a result of oxidation of the metal, is a sign of Antiques bronze products; often bronze is covered with artificial patina to enhance the decorative effect. Among bronze products are especially popular replica or variations on the theme of Antiques from 18-19 centuries. Some jewelry is made of Bronze: pendants, cufflinks, buckles.