Drexel University

Other

Sandvik Intellectual Property Ab

Sandvik Ab

Tamer El-Raghy

Michel W Barsoum

Mats Sundberg

Michael W Barsoum

Kjell Lindgren

Hans Pettersson

Surya Kalidindi

Gustav Malmqvist

Antonios Zavaliangos

Dmitri Brodkin

The present invention relates to a material for use at temperatures exceeding 1200&#xb0; C. and in oxidizing atmospheres consisting generally of an alloy between a metal, aluminium (Al) and carbon (C) or nitrogen (N). The invention is characterized in that the alloy has a composition MAlXwhere M essentially consists of titanium (Ti), chromium (Cr) and/or niobium (Nb) and where X is carbon (C) or where X is nitrogen (N) and/or carbon (C) when M is titanium (Ti); and in that z lies in the range of 1.8 to 2.2, y lies in the range of 0.8-1.2 and w lies in the range 0.8-1.2, and wherein a protective oxide layer of AlOis formed after heating to the mentioned temperature.

Material for high temperatures

A method of producing a single-phase composition MAX, primarily the production of the single-phase material TiSiC, where n lies within a range of 0.8-3.2, where z lies within a range of 0.8-1.2, where M is at least one metal taken from the group of metals Ti (titanium), Sc (scandium), V (vanadium), Cr (chromium), Zr (zirconium), Nb (niobium) and Ta (tantalum), where X is at least one of the non-metals C (carbon) and N nitrogen), and where A is at least one of the chemical elements Si (silicon), Al (aluminum) and Sn (tin) or a compound of those elements, such that the final, desired compound will include the components MAX. A powder mixture of the components is formed and is ignited under an inert atmosphere to prevent promotion of dissociation and to cause the components to react.

Method of producing a metal-containing single-phase composition

A process is provided for forming a material comprising an M X Z phase comprising the steps of: (a) providing a mixture of (i) at least one transition metal species, (ii) at least one co-metal species selected from the group consisting of aluminum species, germanium species and silicon species, and (iii) at least one non-metal species selected from the group consisting of boron species, carbon species and nitrogen species; (b) heating said mixture to a temperature of about 1000&deg; C. to about 1800&deg; C., in an atmosphere within a substantially enclosed heating zone, for a time sufficient to form said M X Z phase; wherein the atmosphere has an O partial pressure of no greater than about 1&times;10 atm. The process provides a substantially single phase material comprising very little MZ -phase. A process for preparing a dense, substantially single-phase M X Z phase workpiece includes providing a highly-pure M X Z -phase powder pre-form and sintering said pre-form at a temperature of about 1000&deg; C. to about 1800&deg; C., in an atmosphere within a substantially enclosed heating zone, for a time sufficient to form a dense, substantially single-phase, M X Z -phase workpiece; wherein the atmosphere has an O partial pressure of no greater than about 1&times;10 atm.

Process for forming 312 phase materials and process for sintering the same

A ceramic material is surface treated by contacting the surface of a 312 ternary ceramic material with a surface-modifying compound selected from carburization agents, silicidation agents, nitridation agents and boronization agents, at an elevated temperature of at least about 600.degree. C. for a period of time sufficient to provide a surface reaction layer of at least about one micron in thickness in the surface-treated material, preferably having a surface hardness in excess of about 6 GPa. A product made by the method of this invention is also disclosed having a surface hardness in excess of about 6 GPa, preferably at least about 10 GPa.

Surface treatment of 312 ternary ceramic materials and products thereof

Products having single phases or solid solutions of the formula M.sub.3 X.sub.1 Z.sub.2 wherein M is a transition metal, X is Si, Al or Ge and Z is B, C or N can be prepared by taking a powdered mixture containing M, X and Z to a temperature of about 1000.degree. C. to about 1800.degree. C., optionally simultaneously under a pressure of about 5 MPa to about 200 MPa. The products so formed have excellent shock resistance, oxidation resistance and machinability. The products may also be present as composites, preferably composites which are in thermal equilibrium with the single phase or solid solutions of the formula M.sub.3 X.sub.1 Z.sub.2.

Synthesis of 312 phases and composites thereof

A dense ceramic workpiece is made by a process of combining a powdered 312 component, e.g., Ti.sub.3 SiC.sub.2, with a powdered component that is soluble in the 312 component, e.g., TiSi.sub.2 in Ti.sub.3 SiC.sub.2, forming the mixture into a green body, heating the green body under pressureless sintering conditions to a temperature above a point at which a liquid is formed but below the melting point of the 312 compound to yield a dense ceramic workpiece, and thereafter cooling the dense 312 ceramic workpiece.

Growing community of inventors

Philadelphia, PA, United States of America

Tamer El-Raghy