The materials

The element nickel - element symbol: Ni, atomic number: 28 - is a real miracle weapon as a metal. At 1,455°C it has an extremely high melting point, it is particularly resistant to chemical substances, very resistant to oxidation, as only one of three elements is ferromagnetic - and therefore quite expensive. For a ton of nickel (as of February 2021) you have to put around 15,000 euros on the table.

So it's good that nickel passes on its excellent properties in alloys to other metals; for example our nickel-based materials. In particularly high concentrations, the nickel content can reach over 50 percent, but even in smaller amounts, nickel makes a steel alloy corrosion-resistant, insensitive to constantly high temperatures - experts also call this creep-resistant - and increases the toughness and tensile strength of the material.

A particularly extreme example of a nickel-based material is the superalloy called Alloy 718. It is creep-resistant up to 700°C, oxidation-resistant up to 1,000°C and has a nickel content of 52.5 percent. It is used wherever the material is exposed to extreme conditions. For example in the turbines of aircraft.

It should also be mentioned that nickel always forms the main component of a nickel-based alloy, although numerous other elements are necessary for the production of modern materials. Alloy 718 already mentioned, for example, still contains 19 percent chromium, 3 percent molybdenum, 0.9 percent aluminum, less than 0.1 percent copper, 5.1 percent niobium and 0.9 percent titanium. As I said: steel production is a science in its own right.

If you want to delve deeper into the subject: The composition of common nickel-based materials is described in DIN 17742, DIN EN 10095, ASTM B168, the material-specific AMS standards for the aviation industry and many other regulations

Whatever the composition of a nickel-based alloy may look in detail, its possible uses are extremely versatile. Nickel alloys are used wherever harsh conditions prevail and materials have to be resistant. These are:

• Mechanical stress: The effect of constant forces and strong moments.
• Chemical stress: attacks of a chemical and electrochemical nature on the surface.
• Thermal stress: the effect of constant as well as abruptly changing temperatures.

Nickel-based materials are therefore used in numerous areas, for example in the chemical industry, aerospace technology, automobile construction and medical technology.

Titanium - element symbol: Ti, atomic number: 22 - has outstanding properties as a metal. It is characterized in particular by its high tensile strength and the natural formation of a protective layer that makes it insensitive to external influences. At the same time, it has a density of just 4.5g/cm³ (for comparison: the density of iron is 7.8g/cm³) and is therefore comparatively light.

Unfortunately, it is also comparatively expensive - very expensive to be precise. A ton of pure titanium costs more than 100.000 euros. This enormous price is not justified by the rarity of the element; in fact, titanium is the ninth most abundant element on our planet. However, the metal is almost never found in its pure state and must first be extracted using extremely complex and expensive processes.

To give you an impression: The production of one kilogram of cement consumes an average of 0.3 kilowatt hours of energy. One kilogram of steel accounts for six kilowatt hours, and one kilogram of plastic even with 19 kilowatt hours.
For one kilogram of titanium, however, 140 kilowatt hours of energy are required - for the same amount an energy-saving lamp could light up for a year and a half or 5,000 cups of coffee could be brewed.

Once extracted, an alloy with titanium gives the steel high strength, toughness and fracture resistance, known in specialist circles as ductility. Due to the already mentioned tendency to form an oxidative protective layer, it is also particularly corrosion-resistant and at the same time lighter than other alloys due to its low density. The metallurgy distinguishes between different grades, classified from 1 to 39. The grades 1 to 4 denote pure titanium in different purities, the grade 5 material most frequently used in industry has a titanium content of 90 percent.

These titanium alloys are therefore used wherever it is not just about the durability of the material, but especially where every gram counts. For example, titanium elements are installed in spaceships, are part of protective equipment for the military and police, or are used in medicine for the manufacture of modern prostheses.

But titanium materials are also finding their way into our normal everyday life. In sports equipment such as golf and tennis rackets, bicycles or mountaineering equipment, the ultra-light material ensures higher performance. And with high-end technology for notebooks and smartphones, a housing made of a titanium alloy protects sensitive components.