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Bronze disease is an irreversible and nearly inexorable corrosion process that occurs when chlorides come into contact with bronze or other copper-bearing alloys. [1] It can occur as both a dark green coating, or as a much lighter whitish fuzzy or furry green coating. [ 1 ]
Bronze, or bronze-like alloys and mixtures, were used for coins over a longer period. Bronze was especially suitable for use in boat and ship fittings prior to the wide employment of stainless steel owing to its combination of toughness and resistance to salt water corrosion. Bronze is still commonly used in ship propellers and submerged bearings.
Aluminium bronzes are most valued for their higher strength and corrosion resistance as compared to other bronze alloys. These alloys are tarnish-resistant and show low rates of corrosion in atmospheric conditions, low oxidation rates at high temperatures, and low reactivity with sulfurous compounds and other exhaust products of combustion.
U.S. government bronze specification H is composed of 83% copper, 14% tin, 3% zinc, and 0.8% phosphorus. [4] Red brass is used to produce pipes, valves, and plumbing fixtures and is considered to offer a good mixture of corrosion resistance, strength and ease of casting. [5] It typically contains 85% copper, 5% tin, 5% lead, and 5% zinc.
Tarnish does not always result from the sole effects of oxygen in the air. For example, silver needs hydrogen sulfide to tarnish, although it may tarnish with oxygen over time. It often appears as a dull, gray or black film or coating over metal. Tarnish is a surface phenomenon that is self-limiting, unlike rust. Only the top few layers of the ...
However, a good rule of thumb: Eating 500 fewer calories per day will help you drop about one pound a week. That might not sound like a lot, but slow and steady weight loss is key, explains Werner.
The corrosion rate of copper in most drinkable waters is less than 2.5 μm/year, at this rate a 15 mm tube with a wall thickness of 0.7 mm would last for about 280 years. In some soft waters the general corrosion rate may increase to 12.5 μm/year, but even at this rate it would take over 50 years to perforate the same tube.
We still don’t know how much of the chemicals actually make their way into the food." And of the amount that does make it into food, only a certain portion will be taken in by the body, Alan says.