Stainless steel offers mechanical properties and durability that make it both functional and attractive. A closer look at a range of domestic appliances will reveal the ubiquity of stainless steel. Inside, it is used for the interior of the dishwasher and the drum of the washing machine and tumble dryer. Outside, stainless steel protects the gas barbeque from the elements. Yet these are only the most visible applications of nickel alloys in everyday consumer goods and are only a few of the situations where nickel-containing materials are used in today’s homes.
Nickel-containing stainless steel and other nickel alloys provide the visual appeal, durability and hygienic properties that make them ideal for use in domestic settings and consumer products. These include kitchen appliances, pots and pans, sinks, taps, cutlery and utensils. Electronic devices, such as laptops and mobile phones, also benefit from these properties.
Consumer goods represent a growth sector for nickel-containing materials, particularly in faster-growing economies such as China and India. Estimates suggest more than 12% of global nickel production is used for major home appliances, mostly in the form of stainless steel.
Another 5% of global production is used in alloy form for building electronic components, taking advantage of nickel’s conductive, magnetic and shielding properties as well as its role in corrosion resistance. Nickel can be found in the heating coils and elements of common electric appliances such as clothes irons, hotplates, toaster ovens, grills, electric blankets, baseboard heaters and soldering irons. These chromium-nickel alloys can contain 20-80% nickel, with some able to resist oxidation and retain their shape at temperatures up to 1250°C (2280°F). Low thermal expansion nickel-iron alloys, containing 36-42% nickel (for example Invar® (UNS K93600)), have long been used in bimetallic strips for thermostats and other temperature control devices.
Other uses of nickel are more tangible; the metal cases of mobile phones and other external parts are frequently made from stainless steel. In addition, it is essential for many of the internal electronics of computers, phones, tablets and other high-tech devices. Nickel-containing stainless steels are also favoured in a host of other everyday items, from the tiny springs found in wristwatches to the heads of golf clubs.
Asked to name the most important room in the home, most people would probably say the kitchen. In every kitchen, it is probably the sink that is the most intensively-used of all the household appliances. Today, most domestic and industrial sinks are made from nickel-containing stainless steel. This makes them robust and long-lasting, properties that work extremely for items in heavy everyday use, irrespective of the various foodstuffs and cleaning chemicals used in the kitchen.
Most stainless steel sinks are constructed from a pressed top surface of stainless steel, into which is welded a deep-drawn bowl. It is the nickel content of the stainless steel that allows the ease and consistency of forming and welding. Most domestic and industrial sinks are manufactured from Type 304 (UNS S30400), which contains 18% chromium and 8-10% nickel. In a more demanding industrial environment, such as those associated with preparing salty foods, grade Type 316 (UNS S31600), which contains 2% molybdenum, may be more appropriate; the molybdenum provides greater corrosion resistance, particularly in the presence of chlorides.
Although not essential for hygiene, a polished stainless steel surface complements the high standards expected in both retail environments and domestic kitchens. This is why most manufacturers polish the surface of their fabricated sinks to a fine finish. A major advantage of stainless steels over softer materials, such as certain synthetics, is their hardness. As scratches and gouges in a sink are less accessible to detergents, they pose a risk of harbouring micro-organisms. However, the resistance of stainless steel to deep scratching means sinks remain hygienic and easy to clean thoroughly. Another important benefit is its recyclability; the stainless steel used in the production of the sinks is 100% recyclable, even at the end of their extended life.
Interior design and construction
On entering most modern buildings, nickel-containing stainless steel is likely to be the material used for many design and construction features.
Nickel-containing stainless steel is everywhere in interior design and construction; in the entrance of the office building, in the elevators of a modern hotel and on the walls of a stylish restaurant. Nickel-containing stainless steel has a huge variety of finishes - bright, matte, embossed or tinted. These different appearances fit perfectly with modern design and interior architecture. In addition to these good looks, nickel-containing stainless steel is also exceptionally hard-wearing and resistant to corrosion, making surfaces easier to clean and extremely long-lasting.
Nickel-containing stainless steel offers an almost infinite range of different formations and uses, allowing designers to bring their most imaginative and innovative ideas to life. In the home, nickel-containing stainless steel can be found in the kitchen and bathrooms, where it is favoured for both its design and functional properties. Meanwhile, behind the walls, the most-advanced water handling and plumbing uses nickel-containing stainless steel for it is durability and low maintenance, allowing an uninterrupted water supply.
In the home
The need to save energy, and ensure our homes are as energy-efficient as possible, is now universally accepted; interest in ‘Energy Saving’ and ‘Energy Efficiency’ are now ubiquitous. Society increasingly demands that manufacturers re-think how homes and offices are heated in winter and kept cool in summer.
About 60% of the energy us to run an average home is used for space heating. A smart decision on heating can go a long way towards saving both energy and money. The most efficient furnaces and boilers currently available use condensing technology. These systems use 35% less energy than standard models.
If a greater proportion of the energy from the fuel is converted into usable heat, the temperature of the exhaust becomes low enough for it to be vented via a small pipe through the wall of the house, thus eliminating the need for a chimney. Condensing furnaces and boilers feature additional advanced heat-exchanger designs to extract maximum heat from the flue gases before they leave the exhaust. These heat exchangers are often made from nickel-containing stainless steel in order to withstand the corrosive nature of the acidic gas and liquid condensation.
It is the strength of the nickel-containing stainless steel that enables these savings in energy and space. In particular, stainless steel is essential in the boiler’s condensation process - the high resistance to corrosion and smooth surface allows the condensation to drain off quickly, leaving no combustion residues. This ensures that the heating is both energy efficient and low maintenance.
In the kitchen
Pots and pans made from nickel-containing stainless steels frequently come with a lifetime guarantee.
The reason manufacturers are able to offer such long guarantees is because the nickel in the stainless steel makes these kitchen essentials exceptionally strong, durable and easy to clean. The best-quality stainless steel used in cookware normally contains 8-10% nickel. This provides extremely hardwearing cookware that can be cleaned thoroughly and repeatedly without the risk of tarnishing or corrosion over time. In addition, nickel-containing stainless steel pots and pans have a smooth surface and are non-porous. Together, these properties mean that stainless steel cookware can resist the regular wear and tear of use in a busy kitchen and still look pristine even after many years of heavy use.
Shape memory in spectacle frames
Dropping or sitting on glasses or sunglasses can risk a costly bill.
However if the frames don't break and miraculously pop back into shape, then they were probably made from a nickel-titanium Shape Memory Alloy (SMA). Nickel-titanium SMAs are 'smart metals', which 'remember' the original shape and can be returned to it following deformation simply by applying heat. With deformed spectacle frames, they simply spring back into their original shape.
The collective name for this family of nickel-titanium alloys is Nitinol. In 1961, Nitinol - derived from 'Nickel Titanium Naval Ordnance Laboratory' - was found to possess this unique property, now called 'shape memory', by a researcher at an American laboratory. Discovery of the shape memory property came about by accident; a strip of Nitinol was presented at a laboratory management meeting, even though it was badly bent. One of the meeting attendees heated it with his pipe lighter; to their surprise, the strip sprang back to its original form.
Modern mobile phones, laptops and digital cameras rely on nickel-containing batteries: lithium ion, nickel metal hydride (NiMH), or nickel-cadmium (NiCd).
The majority of mobile phones and laptop computers are powered by a rechargeable lithium ion battery. Nickel is a critical component of the circuit breaker safety mechanism used in these batteries, using a combination of nickel and resin in the form of a small sheet. When assembled into a battery pack, this circuit breaker maintains safe levels of voltage and current during charging and discharging.
Although custom-sized lithium ion batteries are sometimes used in digital cameras and camcorders, many models rely on common AA-size batteries instead. Many people have already switched from disposable alkaline batteries to a new set of rechargeable nickel metal hydride batteries. These batteries tend to last far longer than standard alkaline batteries. In addition they are rechargeable, meaning they can be re-used hundreds of times. This saves money over time and, by reducing waste, helps protect the environment. Another type of rechargeable battery is Nickel-cadmium, which is available in most popular sizes. NiCd batteries offer the advantage of retaining their charge while not in use. However, theyhold less charge, making them better-suited for uses where they can be regularly plugged in for recharging, such as cordless home telephones, vacuum cleaners and power tools.
Irrespective of the battery type, eventually they will reach a stage when they can no longer be recharged. At the battery’s ‘end-of-life’ it is important that it is recycled. Recycling batteries returns important materials, including nickel, for further use and reduces the demand for virgin materials. This reduces both demand for resources and energy for production.
Going out without a mobile phone feels like leaving home not fully dressed or missing a fundamental accessory.
Although nickel makes up only 1 percent of the total weight of a mobile phone, it is essential for these indispensable devices in a variety of ways. In addition to its role in the battery, nickel is also vital to the core electronic functioning of the device. When opening a mobile phone, there are numerous components and electronic chips attached to a circuit board. One of these - the capacitor - is an essential part of the electronic circuitry. The latest generation of capacitors rely on layers of ultrafine nickel powder; this replaces an older, more expensive technology that relied on precious metals including silver and palladium.
In addition, by reducing the cost of components, nickel is helping to make mobile phone technology more accessible to more people, while smaller parts allow for lighter and sleeker phones. However, the various components must function as a single integrated unit - one that is electronically conductive. Nickel is an essential ingredient in creating this conductivity and ensuring there is a constant electrical current in the phone. As an example, microphones in mobile devices are made of rubber. By mixing nickel powder with silicone to produce this rubber, the end product is conductive and the microphone reliable as a result.