In photovoltaic, wind power or geothermal energy alike, the development of new energy technologies has made enormous strides in recent years. In many industrialized nations today, a considerable portion of annual electricity output is generated from renewable energy sources. Nonetheless, at the global level, power generation from fossil fuels (coal and natural gas) and nuclear energy will not diminish in coming years, but instead will keep growing.
In conventional power generation, the present challenges are to raise efficiency levels at power plants. In these cases, nickel alloys and special alloys often play a decisive role. Added to this is a whole range of peripheral applications in which nickel materials produced by VDM Metals assist in putting environmentally-friendly technologies into operation – in fuel cells, in waste water treatment or in transportation and distribution grids.
Efficiency enhancements in coal-fired power plants are achieved by raising the steam temperatures in boilers and turbines from 600 °C (with pressure at 250 bars) to about 700 °C (350 bars). However, the existing materials used in modern power plant construction are unable to withstand this temperature over time. At the VDM Metals research laboratories, the VDM® Alloy 617 B has been developed specifically as a material with significantly enhanced properties for this field of application. This material is characterized by high strength and ductility with good welding properties.
The solid oxide fuel cell (SOFC) generates clean energy in the form of heat and electricity with high levels of efficiency and thus represents an innovative source of energy for the future. In this form of fuel cell technology, the hydrogen-rich gas that is needed is produced from fuels such as diesel, petrol or methanol at temperatures up to 900°C. Together with the Jülich research center, VDM Metals has developed an enhanced high-performance material for fixed oxide fuel cells, the VDM® Crofer 22 H. The list of the requirements for these materials is long: inside the fuel cell, the material must have high electrical conductivity, corrosion resistance, mechanical stability and resilience as well as ductility, while it must also have no negative effects on the cell. VDM® Crofer 22 H meets all of these highly specific requirements. A further advantage is its expansion values in response to heat. These values match very closely to those of the ceramic used in cells. In this way, no mechanical tension occurs between the two materials that could cause damage to the ceramic.
Due to the high current loads that they carry, high voltage cables heat up and sag. This is prevented with the use of VDM® Alloy 36 Powerline. This high-performance material provides a four-fold reduction in thermal expansion with high mechanical strength so that the volume of transmitted power can be increased. For power supply, this means increased capacity on the power grid carried on efficiently working overhead power lines.
Below the earth's surface, there are boundless reserves of heat commonly referred to as geothermal energy. To be able to tap this energy, one must drill deeply into the earth's crust. The deeper one drills, the hotter conditions get – and therefore the tougher the requirements for the material in the conveyor pipes. On average, the temperature rises by about 3°C for every 100 meters of depth. Alloys made by VDM Metals are the solution: due to their extremely corrosion and fatigue resistant properties, four-high sheet made from VDM® Alloy 625 is used in the production of tubes and pipes.
Safety and reliability are the cornerstones of nuclear power generation. Whether you are working in plant engineering, reprocessing of spent fuel rods or in the field of maintenance, VDM Metals is your ideal partner for demanding material concepts. VDM® Alloy 690, VDM NeutroShield® and VDM FM 52i® are materials typically used in power plant construction and in reprocessing. VDM Metals performs extensive precision testing on each single product according to individual customer specifications to ensure that they possess the required mechanical and corrosion properties, thus contributing to the safe and reliable production of nuclear energy.
The technological demands placed on high-performance materials for stationary turbines are comparable to those for aircraft engines. Here too, the special properties of nickel alloys are needed to ensure safe control of the process and the highest possible efficiency of the equipment. VDM® Alloy 617 and VDM® Alloy 75 are used in various components of stationary turbines. These include combustion chambers, ring blanks, sealing components and internals, in addition to the transition zone between the combustion chamber and the turbine.
Wire meshes made of nickel-copper or nickel-manganese alloys are used as catalysts in waste water treatment and bacteria removal. They generate their effect in the surface treatments carried out by customers or alone through their alloyed composition.