"Doing more with less" is a mantra which is often heard today. Yet it is essential if we are to move towards a more sustainable society. Nickel-containing materials are often at the heart of more efficient use of raw materials and natural resources.
Producing energy and delivering to where it is needed more efficiently and with less environmental impact is a global necessity if we are to have a more sustainable society. Many different technologies are being developed - carbon capture and storage, solar power, wind power, wave power, biofuels and fuell cells for example. One thing which these all have in common is the need for materials to resist aggressive environments or to be finely tuned to deliver a particular combination of mechanical and physical properties. Stainless steels and nickel alloys are frequently chosen for these reasons and also because of their availability and proven performance.
Industrial plant today is expected to last longer and to operate more efficiently. Corrosion resistant nickel alloys can withstand aggressive conditions and high temperatures. This makes them the first choice for many installations in the oil, gas, petrochemical and chemical industries. They enable the equipment to have a long service life and also to operate securely at temperatures and pressures chosen to optimise efficiency. That efficiency is enhanced further by using nickel catalysts, for example in some petrochemical processes and in margarine production. Catalysts increase the chemical reaction speed and yield without being consumed by the reaction.
Modern jet aircraft are much more fuel efficient than those of even a few years ago. This has only been possible because of the nickel alloys which withstand the temperatures and stresses in the hottest parts of the engines. The hotter the combustion, the more efficient the engine can be. However, equally as important is reduction in the weight of the airframe. Contributing to this is the increased use of lightweight composites - often produced in nickel-iron alloy moulds, which have low thermal expansion for dimensional stability. Cars also are ever more fuel efficient. Current hybrid cars rely on nickel metal hydride (NiMH) rechargeable batteries, selected for their performance to weight caracteristics. At end of life, they are fully recycled.
Infrastructure and buildings
Modern society demands an extensive infrastructure - not just roads but airports, water treatment, water distribution and sewage systems. These are expected to have a long operating life - not just to make efficient use of raw materials but also for the sound economic reason of having a low life cycle cost. The corrosion resistance and resulting durability of nickel-containing stainless steels can make a major contribution to this. For example, concrete in coastal installations often experiences serious degradation in a very short time as a result of corrosion of carbon steel reinforcing bar caused by the saline conditions. This can be prevented by the use of stainless steel reinforcing bar in critical areas for relatively little initial cost.
There are many applications of stainless steels in all aspects of water treatment - including desalination - and distribution. Their corrosion resistance means that they can withstand the corrosive conditions without adding extra materials as a corrosion allowance and without providing any corrosion protection. This extends plant life, reduces maintenance and leakage, thus saving precious water. The same considerations apply to plumbing systems within buildings, where stainless steel pipework can withstand the pressures encountered in high-rise buildings. It is lightweight and so is easy to install.
The many decorative applications of stainless steel in buildings are familiar, both on the exterior and in the interior. Less familiar are the contributions which nickel-containing stainless steels can make to "green" buildings, through improved energy efficiency, reduced emissions, durability and reduced environmental impact. This is of considerable interest today as the building codes are changed and it is discussed in more detail in an "Ask the Expert" feature in the current printed edition of "MENA Infrastructure".
Perhaps nothing eptomises the rapid technological changes of recent years more than electronics. The ubiquitous mobile phone, the personal computer and portable music players: all these rely for their operation and small size on the characteristics of nickel-containing materials which make possible not only the NiMH batteries but also small capacitators, transducers, high storage density hard disc drives and the moulds used to produce CDs and DVDs. These modern technologies are much less material intensive than their predecessors. Many of these components are produced by a surface treatment process which deposits thin layers of nickel from a chemical solution. It is the same process which produces the thin layer of nickel under the chromium top layer of the familiar chromium plated articles.
It may take many years but all buildings, industrial plants and household goods will eventually reach the end of their useful service lives. Mechanisms have existed for years to recover and recycle valuable raw materials, particularly metals. So much so, that these recycled materials are now considered as secondary raw materials. Stainless steels (often containing around 18% chromium and 10% nickel) and nickel alloys are no exceptions. Their intrinsic value encourages recovery and recycling. Stainless steel is remelted and recycled to new stainless steel, thus recycling and conserving the chromium and nickel. There is no loss of quality and the new stainless steel is not in any way inferior to the old. It is estimated that over 80% of stainless steel is recovered in this way at end of life, making it one of the most recycled metals. However, simply because stainless steel generally remains in service for very many years, it is always necessary to add new raw materials to produce the stainless steel which is needed today. Without that recycling, far more raw materials and energy would be consumed.
To learn more about these and other ways in which nickel-containing materials are contributing to society, or to get technical information, please visit the Material Selection and Use pages.