Factors to Consider When Choosing a Metal
Corrosion
The main disadvantage of steel is that it rusts. It needs to be protected by a coating that doesn’t corrode, such as paint or non-ferrous metal.
Roofing iron is coated with zinc, which doesn’t corrode in air or water. If the surface is meant to be shiny and wear-resistant, then chromium is the best.
Nickel is similar to chromium, and almost it’s hard. Both are put onto the base metal by electroplating. In nickel and chromium plating, a series of chemical baths clean the surface before the electroplating deposits a thin, even nickel layer.
In this case, only certain parts are to be plated, so the rest is coated with wax. The thickness of the coat could be controlled by the length of time the plating continues.
Copper is a good conductor, so it spreads the heat evenly over the pot’s bottom, but it is too soft. The best solution is to have a stainless-steel body with a copper bottom.
Copper reacts with carbon dioxide in the air to form a green compound copper carbonate. As this process takes a few years, manufacturers nowadays produced this green color in the factory.
Aluminum oxidizes easily, forming a strong layer to protect it. This stops any further corrosion, and it’s one reason aluminum is used outdoors.
Chromium and nickel oxidize in the air, but the oxide layer is clear, preventing any more oxygen from reacting with the metal.
Many other non-ferrous metals a corrosion-resistant because their oxide layers are impervious to oxygen.
This is why zinc and aluminum are corrosion resistant.
Heat Treatment of Metals
Heat treatment can change the material’s properties. Working with copper hardens it and makes it brittle. If we quench it that is heated, then rapidly cool it. Its effect is to soften the copper. The opposite happens to steel.
Electrical Conductivity
Metals are all good electrical conductors, but some are better than others.
Copper shows the least resistance. In other words, it conducts electricity better than steel. Even though copper is the best conductor, many high voltage power lines are actually aluminum.
Aluminum is lighter than copper, so the towers do not have to hold much weight. Aluminum is cheaper than copper as well.
Electrochemical Properties
When you mix metals, you can have trouble. Joining copper to zinc will produce an electrochemical reaction. It will generate electricity, which is very useful if you want a battery, but you will have corrosion in your job.
Plumbers prevent this with Teflon type. You can use steel bolts on aluminum, zinc, or chromium because the outside prevents electricity from flowing. Some combinations work; some don’t.
