Refractory ceramic product

Abstract

The invention relates to a refractory ceramic product.

Claims

1. A refractory ceramic product having the following features: 1.1 the product comprises crystallites in the form of a MAX phase; 1.2 the crystallites in the form of the MAX phase comprise crystallites with a diameter of at least 10 m.

2. The product as claimed in claim 1, comprising at least one refractory base material.

3. The product as claimed in at least one of the preceding claims, based on a refractory base material in the form of aluminum oxide.

4. The product as claimed in at least one of the preceding claims, with a MAX phase in the form of Ti3SiC2.

5. The product as claimed in at least one of the preceding claims, in which the crystallites in the form of a MAX phase are embedded in a matrix formed by at least one refractory base material.

6. The product as claimed in at least one of the preceding claims, in the form of a solidified melt.

7. The product as claimed in at least one of the preceding claims, in which the crystallites in the form of a MAX phase comprise crystallites with a diameter of at least 100 m.

8. The product as claimed in at least one of the preceding claims, in which at least 90% by weight of the crystallites in the form of a MAX phase have a mean diameter of at least 10 m.

9. A finished product which comprises a product as claimed in at least one of the preceding claims.

Description

(1) In the accompanying figures:

(2) FIG. 1 shows a micrograph under reflected light of a microsection of the refractory ceramic product produced in accordance with the exemplary embodiment,

(3) FIG. 2 shows section A of FIG. 1 under reflected light,

(4) FIG. 3 shows section A of FIG. 1 under reflected light under crossed polarizers, and

(5) FIG. 4 shows section A of FIG. 1 under reflected light under crossed polarizers and with the diameters of the crystallites in the form of MAX phases marked.

(6) FIG. 1 shows a section of an image under reflected light of a microsection of a polished section of the refractory ceramic product which had been produced in accordance with the exemplary embodiment. The black bar at the bottom right hand side in FIG. 1 corresponds to a length of 2 mm, and so the entire section had a surface area of approximately 12.39.2 mm. In FIG. 1, a dark grey matrix 1 formed from corundum can be seen in which the other MAX phases, which are lighter in FIG. 1, and provided with the reference numeral 2, are embedded in the manner of islands.

(7) An enlarged section A of FIG. 1 in which a region of this type in the form of a MAX phase 2 is present is shown in FIG. 2. The black bar at the bottom right hand side in FIG. 1 corresponds to a length of 200 m, and so the entire section has a surface area of 1.20.9 mm.

(8) The MAX phase 2 of FIG. 2 exhibits many crystallites 3, 4, 5, 6, 7, 8, 9 in the form of MAX phases the crystallite boundaries or grain boundaries of which are shown as white lines in FIG. 2. Similarly sized crystallites 3, 4, 5, 6, 7, 8, 9 were also examined using the Intercept Procedure determination of the mean diameter of the crystallites of ASTM E 11296 (Reapproved).sup.e2. Smaller crystallites, for example those denoted in FIG. 2 with the reference numeral 10, and whichwith respect to the total weight of the crystallites in the form of the MAX phasewere clearly below 10% by weight, were not considered.

(9) FIG. 3 shows the section of FIG. 2 under crossed polarizers, wherein the individual crystallites 3, 4, 5, 6, 7, 8, 9 appear in different shades of grey.

(10) FIG. 4 shows the section of FIG. 2, wherein in the crystallites 3, 4, 5, 6, 7, 8, 9, a diameter shown by the double-headed arrow was measured at any cross-sectional surface of the crystallites 3, 4, 5, 6, 7, 8, 9. The diameters had sizes in the range from approximately 440 to 560 m, and thus had a respective diameter of at least 10 m.

(11) The refractory ceramic product produced in accordance with the exemplary embodiment has an excellent corrosion resistance, in particular as regards metallic slags and metal melts.

(12) The refractory ceramic product produced in accordance with the exemplary embodiment is therefore eminently suitable for use as a raw material for the production of finished refractory ceramic products in order to improve the corrosion resistance of a product produced from this product.