Heraeus Developments

By the 19th century, platinum was a prized metal for jewelry manufacture, but could not be processed on an industrial scale. In 1856, Wilhelm Carl Heraeus changed the situation. Using a high-heat oxyhydrogen fan burner he had developed, he melt kilogram quantities of platinum for the first time. With the “First German platinum melting house W. C. Heraeus” he laid the cornerstone for the precious metals and technology group Heraeus. In 1857 W. C. Heraeus produced 30 kilograms of pure platinum, but by 1896 the volume was already more than 1,000 kilograms.

Good laboratory chemical resistance to aggressive media, high melting points and stability at high temperatures are the fundamental characteristics which have distinguished platinum and platinum alloys as laboratory materials. Since about 1870, Heraeus has produced crucibles, casting dishes or boats that are used as standard laboratory equipment in analysis, for example, for microanalysis or fusions. Today, platinum crucibles are manufactured to customer specifications in sizes between that of a thimble and a wine cask.

The German Imperial Patent Office granted Patent No. 63591 for the gilding of platinum plate was the first patent in the corporate history of Heraeus. Until the beginning of the 20th century, sulfuric acid (one of the most important chemical base products) was produced using the lead chamber process and heated and concentrated in platinum vessels (of up to 50 kg platinum). The gilded platinum vessels developed by Heraeus were even more resistant to the corrosive acid than pure platinum and reduced platinum losses by ten times.

Heraeus has provided materials for the refinement of glass and ceramic surfaces since 1896. Ceramic colors containing precious metals such as bright gold, bright platinum or burnish gold are used to produce the gold rims on porcelain plates or the fine decorations on champagne glasses. The decorations are produced by firing the preparations at temperatures far above 1000°C. A new generation of thermoplastic bright gold and bright platinum pastes for glass makes it possible to produce top quality dishwasher-safe decorations.

Richard Küch produced high-purity bubble-free quartz glass for the first time by melting rock crystal (at approximately 2000°C), thus obtaining a new material with special properties and applications. Heraeus first used the acid-stable, light-permeable and high-purity high tech material to produce laboratory equipment for the chemical industry. Applications in optics (optical quartz glass), temperature measurement (platinum resistance thermometer) and lamps (Original Hanau Höhensonne artificial sunlamp) soon followed.

The patent application for a forge welding process in 1900 signified a breakthrough for Heraeus in the manufacture of chemical equipment with base metals, aluminum in particular. The process made it possible to manufacture large vessels from aluminum plate. They were seamlessly welded together by forging. The large aluminum vessels were used as fermentation tanks in breweries or as storage tanks by the chemical industry.

By patenting the first tube furnace with a platinum film heating coil, Heraeus captured a new market. Electrothermal furnaces for temperatures up to 1500°C were part of the inventory of research laboratories all over the world. Platinum-rhodium thermoelements from Heraeus were used to measure the temperatures. "Incubators" for bacteriological studies followed in the 1920s. Thermal furnaces and drying cabinets were used for curing, drying, temperature control or evaporation. Special furnaces reached temperatures above 2000°C.

Richard Küch developed the first quartz glass lamp that produced ultraviolet light identical to sunlight. The Original Hanau® qualifies Heraeus as the inventor of the UV high pressure lamp and as a pioneer in tanning using artificial light sources, e g. for medical phototherapy. In the 1950s, the small Höhensonne® advanced to become an electrical consumer item as a tanning lamp.

In 1906 an “electric resistance thermometer made of platinum wire” was patented by W. C. Heraeus. It was the birth of modern temperature measurement technology. The innovative design (platinum wire wrapped on quartz glass, surrounded by a protective tube made of quartz glass) made it possible to quickly and reliably measure high temperatures. The wrapped platinum resistance thermometers set industry standards in temperature measurement for about 70 years, for example in power plants and chemical production facilities.

In 1912, Wilhelm Rohn introduced vacuum metallurgy to Heraeus. In specially developed electric resistance furnaces, refractory base metals were melted and completely new alloys were produced. They included chromium-nickel alloys as an alternative to platinum wires in thermoelements or nickel-iron alloys for transmitter and receiving systems in communications. Starting in the 1920s, Heraeus produced base metal alloys by the ton in induction furnaces.

Platinum is a catalyst with a variety of applications. For the ammonia combustion process in the industrial production of nitric acid (an initial product for artificial fertilizers), ammonia with oxygen is passed over glowing platinum gauzes made from ultrafine platinum wires. Heraeus has produced these gauzes since 1916, after having produced only platinum wires before that. In 1928, platinum was replaced by platinum-rhodium wires. Today, Heraeus supplies gauzes having diameters greater than six meters to the chemical industry.

Alba alloys from Heraeus captured the dental market. They were a cost-effective alternative to gold for dentures and fillings. Alba contains only about 5% gold elsewise palladium and silver as well as cobalt and nickel as a hardening component. Alba alloys behave like conventional gold alloys. Of critical importance for the production of these biocompatible, readily castable precious metal alloys was the use of the thermal tempering quality of these alloys, which made it possible to specifically adjust the physical properties of the alloys.

In 1934, Heraeus introduced a bubble-free, ream-free and stress-free, optically perfect quartz glass named Homosil. To create a product of this quality, Heraeus developed a special process, the “scatter process.” Owing to their high quality, from the 1950s on, the optical quartz glasses from Heraeus gained more and more ground in new challenging applications in astrophysics, space technology, microelectronics, optical telecommunications and the semiconductor industry.

In 1936, Heraeus pioneered in high-vacuum vaporization technology. Metals are vaporized in a high vacuum and thin layers of metal are produced on polished surfaces of substrate materials. A milestone for Heraeus was the production of high-quality mirror surfaces through the vaporization of thin layers of rhodium on glass. In contrast to the silver or aluminum layers used previously, the rhodium layers have outstanding reflectivity and high chemical and mechanical stability.

For a long time, rock crystal was the only raw material for the production of quartz glass. In 1955, Heraeus produced “synthetic quartz glass” for the first time. Using a special fan apparatus, a silicon-containing compound was caused to react with oxygen in a hot hydrogen flame. An extremely pure, bubble-free and ream-free quartz glass with high UV permeability was produced from the deposited particles. Under the brand name Suprasil, it was used in space technology, for example, as a mirror and window material.

In 1959, the first Heraeus roll cladding mill went into operation. In roll cladding, rollers press narrow ribbons of a precious metal onto base metal carriers, such as copper ribbons, under high pressure. The ribbons are processed into contact parts just millimeters thick, and the fine ribbons of precious metal facilitate the electrical contact. These stamped parts soon became important components, such as ESK high-speed relays, that are produced by the millions for use in electrical switching technology.

Quartz glass from Hanau is also on the moon. The Apollo 11 mission not only took the first man to the moon but also a laser reflector to determine the precise distance from the Earth to the moon. The mirror is beamed with a laser beam, which is guided back again by 100 quartz glass triple prisms and the distance is determined from the transit time. The reflector is still in use today. For this special order, Heraeus further developed the quartz glass Suprasil into Lunasil with long-term stability in space.

When it comes to anchoring a hip prosthesis securely to the bone, the Heraeus bone cement Palacos® has set the standard since 1959. It has also proven effective as a base for antibiotics, thus reducing the risk of infection in joint replacement surgery. The first bone cement with antibiotic agents followed in 1972 Long-term clinical trials and clinical documentation confirm that prostheses cemented with Palacos® have a particularly long service life.

In 1974 Heraeus took the next important step in the optimization of sensors when it developed a platinum resistance thermometer based on thin film technology. Now it was possible to miniaturize sensors and produce them in high quantities. As a consequence, platinum sensors could be used for a growing number of applications, for instance for the measurement of temperatures between -196°C and +1000°C. The production of thin film sensors is a state-of-the-art technology with similarly high standards as the semiconductor industry.

Heraeus ranks as a global leader in the manufacture of platinum-based pharmaceutical agents for cancer treatment (chemotherapy). Cisplatin, carboplatin and oxaliplatin have played an important role in combating cancer for as much as 30 years. Heraeus gained the expertise required to synthesize these highly active pharmaceutical ingredients from more than 160 years of experience in handling and processing precious metals. Heraeus has consistently built up these activities and today manufactures both organically and biotechnically produced antitumor agents.

Since 1982, Heraeus has brought greater quality of life to patients through medical technology. Firmly anchored in the heart muscle, stimulation electrodes made of platinum, platinum alloys, titanium or tantalum perform valuable assistance for cardiac pacemakers and implantable defibrillators. The biocompatible electrodes that are used as coated helical, head or annular electrodes deliver the pulses of the cardiac pacemaker to the heart muscle. The small electrodes of only millimeters in size are coated with special materials.

Microchips would not function without the product know-how and connecting technology from Heraeus. Leadframes, extremely thin layers of precious metal contact alloys, carry the microchips. Micrometer-thin bonding wires of gold, aluminum, copper or palladium have become indispensable for the electrically conductive connections of the semiconductor components and in the electronics industry. Electronic components are mounted on circuit boards using soldering pastes and conducting and non-conducting adhesives.

With the electron beam smelter, Heraeus was already producing high-purity special metals such as titanium, molybdenum or tungsten in the 1960s. A metal cylinder is bombarded with electron beams in a high vacuum; the metal melts, is purified in the process and forms a new cylinder. With one of the largest electron beam smelters in Europe, Heraeus produces the purest niobium in the world, for high energy physics, for example, since 1984. Among other things, superconducting cavity resonators in particle accelerators are made of niobium.

Since natural quartz glass no longer satisfies the rising demands for material purity and transparency for optical fibers, Heraeus developed a process for producing high-purity fused silica glass from the gaseous phase in 1987. Synthetic quartz glass makes it possible to reduce the metallic impurities and traces of moisture present in natural silica by several orders of magnitude. The quartz glass preforms produced by Heraeus account for approximately 95% of the glass fibers for optical communications transmission.

Quartz glass is an important material for the semiconductor industry. In microlithography, silicon wafers are exposed for microchip production using quartz glass lens systems. In 1992, Heraeus developed Suprasil 311 as a new generation of synthetic, optically homogeneous quartz glass for lenses for DUV (deep ultraviolet) microlithography. In 2004, Heraeus achieved a breakthrough for lithography applications in the 193 nanometer range with an additional quartz glass generation.

Infrared emitters from Heraeus quickly produce targeted thermal radiation at the push of a button. Carbon infrared radiation (CIR) developed in 1993 is a special form of medium-wave infrared radiation. Carbon emitters have high efficiency for drying processes and plastics processing; they can be switched on and off very rapidly and are energy saving for individual heating processes. The emitters are suited for targeted heating of defined surfaces and for fast drying of water-based coatings.

Heraeus produces sputtering targets for the functional coating of large glass surfaces. These layers provide thermal insulation or solar protection. At first flat sputtering targets were predominantly used for the coating of glass surfaces. By developing rotatable sputtering targets, Heraeus has gone a step further. The composition, density and purity of the cylindrical targets meet the high quality standards of the planar formed targets; however, they reduce the coating costs due to the improved material utilization.

The sensor for measuring aluminum in liquid zinc developed by Heraeus is an innovation for the steel industry. Zinc is used to protect steel against corrosion. Small quantities of aluminum are added to stabilize the zinc. The AlZin sensor makes it possible to measure the concentration directly and continuously in the zinc bath. This means users can adjust the aluminum proportion immediately in the event of deviations - with less spoilage and a time and cost advantage in the steel industry.

The production of fertilizers (ammonia combustion process) requires large quantities of catalysts made of platinum gauzes. An unwanted byproduct of the process is ozone damaging laughing gas (N2O), a greenhouse gas that is 300 times as powerful as carbon dioxide. Heraeus developed a multiphase catalyst that selectively destroys laughing gas when it is formed. A downstream secondary catalyst in combination with the platinum gauzes directly above it reduces the emission of the greenhouse gas by more than 90%.

Silver, in the form of conductive pastes, plays an important role in the electronics and photovoltaic industries. This includes silver-based pastes for manufacturing very delicate, high-conductivity contact paths on solar cells. These constitute the tracks on the solar cells. The electroplating pastes make it possible to produce highly efficient crystalline solar cells. Heraeus is constantly developing new formulas in order to offer customers innovative technology solutions. The requirements for new generations of paste include high efficiency, low consumption, and reduced silver content.

Under the brand name Clevios™, Heraeus produces conductive polymers that take the form of bluish dispersions; they form electrical functional coatings on flexible touch screens for smartphones and tablet PCs. These intuitive user interfaces are based on innovative microelectronics on thin films with conductive coatings. With a combination of various conductive polymers Heraeus has succeeded in making these functional films on touchscreens completely invisible to the human eye.