Wikijunior:How Things Are Made/Metal/Brass

Products

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  Items that are made of brass

Brass is stronger and harder than copper, but not as strong or hard as steel. Brasses with a higher percentages of zinc are stronger and harder, but they are also more difficult to form and have less corrosion resistance. The zinc used to make brass is a commercial grade sometimes known as spelter.

What do we need to make this thing?

Brass is a metal composed primarily of copper and zinc. Copper is the main component, and brass is usually classified as a copper alloy.

The main component of brass is copper (varies between 55% and 95% by weight) which are made from electrically refined copper that is at least 99.3% pure to minimize the amount of other materials. The second component of brass is zinc. The amount of zinc varies between 5% and 40% by weight depending on the type of brass. Some brasses also contain small percentages of other materials to improve certain characteristics. Such metals as lead to improve machinability, tin improves corrosion resistance, iron makes the brass harder and makes the internal grain structure smaller so that brass can be shaped by repeated impacts in a process called forging.

What is the step by step process?

Step by step (Preferable in bullet point list)

• Step 1: The appropriate amount of suitable copper alloy scrap is weighed and transferred into an electric furnace where it is melted at about 1,0500C. After adjusting for the

amount of zinc in the scrap alloy, an appropriate amount of zinc is added after the copper melts. A small amount of additional zinc, about 50% of the total zinc required, may be added to compensate for any zinc that vaporizes during the melting operation. If any other materials are required for the particular brass formulation, they are also added if they were not present in the copper scrap.

• Step 2: The molten metal is poured into molds and allowed to solidify into slabs called cakes.
• Step 3: When the cakes are cool enough to be moved, they are dumped out of the molds and moved to the rolling area where they are stored.
• Step 4: The cakes are placed in a furnace and are reheated until they reach the desired temperature. The temperature depends on the final shape and properties of the brass stock.
• Step 5: The heated cakes are then fed through a series of opposing steel rollers which reduce the thickness of the brass step-by-step to about 13mm or less. At the same time, the width of the brass increases. This process is sometimes called breakdown rolling.
• Step 6: As the brass is hot rolled it gets harder and more difficult to work. It also loses its ductility, or ability to be stretched further. Before the brass can be rolled further, it must first be heated to relieve some of its

hardness and make it more ductile. This process is called annealing. The annealing temperatures and times vary according to the brass composition and desired properties.

• Step 7: The annealed pieces of brass are then fed through another series of rollers to further reduce their thickness to about 2.5 mm. This process is called cold rolling because the temperature of the brass is much lower than the temperature during hot rolling. Cold-rolling mills are designed to minimize deflection across the width of the rollers in order to produce brass sheets with near-uniform thickness.
• Step 8: At this point, the wide sheets may be slit into narrower sections to produce brass strip. The strip may then be given an acid bath and rinse to clean it.
• Step 9: The sheets may be given a final cold rolling to tighten the tolerances on the thickness or to produce a very smooth surface finish. They are then cut to size, stacked or coiled depending on their thickness and intended use, and sent to the warehouse for distribution.

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  Step 1: Alloys are melted inside the electrical furnace
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  Step 2: The melted brass are poured into mold to form ingots
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  Step 3: Robotic hand take the mould to remove ingot from inside the mould
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  Step 5: The roller are annealing the brass sheet
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  Step 6: The brass sheet are cold milling