Energy & Green Tech

Non-noble catalyst for hydrogen production

Hydrogen is a promising future fuel—especially if produced from water—but the necessary noble metal catalysts are rare, expensive, and have insufficient reserves. But now, in a study recently published in Advanced Materials, ...

Engineering

Understanding corrosion in concrete sewer pipes

Using neutron imaging techniques at ANSTO, researchers from Macquarie University have gained a better understanding of how corrosion forms and spreads through concrete that is commonly used in sewer pipes.

Energy & Green Tech

Wave-powered SeaRAY preps for Hawaii trial

Offshore industries, like marine research, fish farming, and mineral mining, often rely on big ships with large crews. Without clean energy to power these vessels, each trip out to sea and back to shore is not only expensive ...

Engineering

'Sensing skin' detects cracks, harmful chemicals in structures

Researchers have developed a multi-layered "sensing skin" to detect corrosive or otherwise harmful substances in structures. The skin can also detect cracks and other structural flaws that are invisible to the naked eye.

Corrosion

Corrosion is the disintegration of an engineered material into its constituent atoms due to chemical reactions with its surroundings. In the most common use of the word, this means electrochemical oxidation of metals in reaction with an oxidant such as oxygen. Formation of an oxide of iron due to oxidation of the iron atoms in solid solution is a well-known example of electrochemical corrosion, commonly known as rusting. This type of damage typically produces oxide(s) and/or salt(s) of the original metal. Corrosion can also occur in materials other than metals, such as ceramics or polymers, although in this context, the term degradation is more common.

In other words, corrosion is the wearing away of metals due to a chemical reaction.

Many structural alloys corrode merely from exposure to moisture in the air, but the process can be strongly affected by exposure to certain substances (see below). Corrosion can be concentrated locally to form a pit or crack, or it can extend across a wide area more or less uniformly corroding the surface. Because corrosion is a diffusion controlled process, it occurs on exposed surfaces. As a result, methods to reduce the activity of the exposed surface, such as passivation and chromate-conversion, can increase a material's corrosion resistance. However, some corrosion mechanisms are less visible and less predictable.

This text uses material from Wikipedia, licensed under CC BY-SA