SU639835A1 - Charge for making refractory material - Google Patents

Description

one

The invention relates to reinforced filiform crystals of refractory materials that may be used as structural materials in high temperature engineering.

Known refractory material based on magnesian-alumina spinel, reinforced with sapphire threadlike crystals. The material has high strength characteristics 1.

Closest to the invention is a mixture for the manufacture of a refractory material, including magnesia-alumina spinel AND bonded, based on chloride and rare earth oxychloride (3 wt.%) {2.

However, this material has a low temperature resistance (3-4 heat shifts according to the 950 ° C mode — water).

The purpose of the invention is to increase the heat resistance of the refractory material.

This goal is achieved by the fact that the mixture for the manufacture of refractory material, including, and magnesia-alumina spinel and binder - oxisol rare earth element, additionally contains filamentary crystals of silicon nitride, and as a binder - lanthanum okoinitrate in the following ratio of components, weight. %:

Lanthanum oxynitrate1-10

Threadlike crystals

silicon nitride 1 -15

Magnesia Alumina

Refractory material prepared by the following technology.

An oxynitrate binder is added to the MgAl2O4 powder (5). The mass is mixed and passed through a sieve. Then, Si3N4 whiskers are introduced into the mixture. The mass is again passed through a sieve. After this, the mass is moistened with 6–8% water and the samples are pressed at a pressure of 1000 kg / cm (cylinders with a diameter of 15 mm and a height of 25 mm).

The obtained samples are burned in a controlled atmosphere of nitrogen or argon at 1700 ° C.

Example. To 30 grams of MgAl2O4 was added 3 g of lanthanum hydroxy nitrate powder. The mass is mixed and passed through a sieve. Then, 0.3 g of SisN whiskers is introduced into the mixture, and the mass is again passed through a sieve. After that, the mass is moistened with 6% water and the samples are pressed at a pressure of 1000 kg / cm.

The obtained samples are burned in a controlled atmosphere of argon at a temperature of 1700 ° C.

Properties of samples of different composition after calcination in an argon atmosphere at 1700 ° C are shown in the table.

As can be seen from the table, the addition of whiskers of silicon nitride significantly increases the heat resistance of the material, which makes it possible to use it in conditions of a sharp temperature drop.

Claims (2)

Invention Formula The mixture for the manufacture of fire saddle material, including magnesia-alumina spinel and a binder - oxisol of a rare-earth element, characterized in that, in order to improve heat resistance, it additionally contains filamentous silicon nitride crystals, and as a binder - lanthanum nitrite in the following ratio components weight. 1 - 10 Oxanitrate Lanthanum Threaded Crystals 1-15 Silicon nitride Magnesia alumina spinelEmost Sources of information taken into account in the examination 1. Zimmer Curtis E a. but. Compos and Carbon III Symp. Asheg. Soc. Segagp. 1973 Chicago, 1971, Columbus, Ohio, 84-95. the USSR 2. Copyright certificate № 512202, cl. C 04b 35/00, 1973.