Information and Services associated with Glass Making

We are certified to DIN EN ISO 9001:2008 and DIN EN ISO 14001 . In the manufacture of high quality products, we work to the 5S standard and monitor processes by audit management. SixSigma tools are used for systematic process optimization.

We employ analytical processes such as GDL, XRF, and LECO to ensure constant material quality. Semi-finished products and welded finished products can also be examined by ultrasonic and X-ray techniques for possible porosity.

The physical, elastic, and mechanical properties are determined both in house and at external independent universities to obtain qualitatively high value material data.

Additional metallographic examinations and methods such as SEM, EDX, ICP, AES, SIMS, and XRD are additional techniques available for the investigation of used components or in case of damage, e.g., by corrosion.

It is sometimes not appreciated that platinum forms a thin oxide film at room temperature that evaporates at higher temperatures. This can be reduced by means of special protective coatings.

It is known that welding leads to a reduction in strength relative to the initial material in a very wide range of material groups. For the Heraeus DPH materials, however, the use of optimized welding parameters and adapted material properties allow the strength to be maintained at a very high level. By means of an FEM supported optimization of the design, the welds can furthermore be positioned in areas with lower stress levels.

It is not recommended to weld platinum to copper because of the formation of brittle phases which have a mechanical influence above 600°C. This can be neatly avoided by the material combination Pt-Pd-Cu. Furthermore, it is possible to weld Pt with nickel-base materials and stainless steels.

Platinum and metals of the platinum group demonstrate excellent chemical and thermal resistance to glass melts. However, there is a series of “platinum poisons” that, even in small quantities, can damage the material.

Damage through a reduction of the melting point.

Platinum Poison Melting point with Pt [°C] Melting point with Rh [°C]
B (Bor) 825 1131
Si (Silizium) 830 1389
As (Arsen) 597 -
Sn (Zinn) 1070 -
Sb (Antimon) 633 610
Pb (Blei) 290 -
Bi (Wismut) 730 -
P (Phosphor) 588 1245
S (Schwefel) 1240 925

B, Si, As, Sn, Sb, Pb, Bi

As is known from the classical example of solder, the melting point of the mixture of tin and lead (183°C) is lower than that of the pure metals tin (232°C) and lead (327°C). This effect of the reduction in melting point also occurs when platinum metals come into contact with these elements.

Phosphorus

Phosphorus is one of the classical “platinum poisons” with one of the lowest eutectic temperatures. With phosphorus in the form of phosphates, on the other hand, catastrophic corrosion does not occur. This can, however, lead to an increase in the surface roughness and to mechanical embrittlement.

Sulfur

Whereas sulfur in the form of sulfates is relatively harmless, sulfides can cause substantial embrittlement of the platinum components.

Further Elements and Compounds

Carbon

Besides its influence in reducing oxides of the “platinum poisons”, carbon can diffuse into the grain boundaries and can cause a separation of the grain boundaries, leading to porosity.

Carbides and silicides

Contact with silicon carbide (e.g., SiC-insulating ceramic), or with molybdenum disilicide (MoSi2-heating elements) leads to immediate melting of the material and thus to the failure of the component.

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