DECHEMA

About: DECHEMA is a nonprofit organization based out in Frankfurt am Main, Germany. It is known for research contribution in the topics: Corrosion & Oxide. The organization has 756 authors who have published 1307 publications receiving 25693 citations.

Application of an alloy from aluminium and titanium as well as a coating material for such an application

Abstract: An alloy of aluminum and titanium is used as a high temperature corrosion resistant coating material of heat resistant steels in installations with process gases which have a very low partial pressure of oxygen and, as consequence of carbon compounds in their composition, possess a high carbon activity. The claimed coating material has an atomic aluminum content amounts to 22-56 %.

Materials for temperatures above 1500°C in oxidizing atmospheres. Part III: Contact reaction tests

Abstract: The topic Materials for Temperatures above 1500 °C in Oxidizing Atmospheres is discussed in a 3 part publication. In the first part [1] a literature survey had led to two potential material systems consisting either of particle reinforced MoSi 2 or of a MoSi 2 based oxidation resistant coating on creep resistant RSiC. Both systems were verified experimentally in a second publication [2] including the development of optimum oxidation resistant MoSi 2 composite materials and of an optimum coating system on RSiC. The present part deals with the contact corrosion behavior of these silica formers if other refractory materials are used in combination with these material systems as it is often the necessity in practical applications. Therefore, the contact reactions of MoSi 2 with 10 other high temperature oxide based structural materials were investigated at 1600 °C in air. The results are mainly documented by microprobe investigations with respect to the contact reaction products formed. It was found that only two material combinations are conceivable for long-term use in contact with MoSi 2 . The results are in agreement with the considerations discussed in part one of this publication [1].

Titanium@-aluminium@ alloy powder with improved high temperature corrosion resistance

Abstract: A titanium-aluminium alloy part is treated with a gaseous halogen-containing compound which reacts with the workpiece surface.

Discontinuities in Oxidation Kinetics: A New Model and its Application to Cr–Si-Base Alloys

Abstract: Some alloys such as many Cr-based systems show mass gain discontinuities during thermogravimetric measurements which strongly affect the oxidation kinetics. The behaviour cannot be described by the current models available in the literature. Thus, a novel $$k_\mathrm{para}$$ – $$k_\mathrm{lin}$$ -P-model was developed to describe oxidation kinetics during the isothermal exposure of materials which show such behaviour. Beside the parabolic rate constant $$k_\mathrm{para}$$ and the linear mass loss constant $$k_\mathrm{lin}$$ , the P-value and $$f_P$$ are introduced to take into account spontaneous rapid mass gains due to local oxide scale failure. The parameter P serves as a measure for the mass gain due to discontinuous events and $$f_P$$ is the frequency of such events. The both parameters can be related to oxide scale detachment and growth stresses. The application of the model is demonstrated for the oxidation of Cr–Si-based alloys in synthetic air at $$1200^{\circ }\hbox {C}$$ for 100 h. For these alloys, the origin of the mass gain discontinuities is discussed and the meaning of P and $$f_P$$ is explained in more detail. Using this newly developed model, an insight into growth and nitridation resistance of oxide scales as well as scale adhesion is gained.