RU-2861699-C1 - METHOD FOR PRODUCING CERAMIC PRODUCT BASED ON Al2O3 AND ZrO2

Abstract

FIELD: ceramic technologies. SUBSTANCE: invention relates to a method for producing high-strength and wear-resistant ceramic parts and coatings based on aluminium oxide (Al 2 O 3 ) and zirconium oxide (ZrO 2 ), which can be used in aircraft construction, mechanical engineering, medicine, chemical and electronic industries under conditions of increased wear, aggressive media and high temperatures. The method for producing a ceramic product based on aluminium oxide Al 2 O 3 and zirconium oxide ZrO 2 includes the stages of preparing a charge containing 80 mas.% aluminium oxide and 20 mas.% zirconium oxide, melting it in a graphite melting chamber under the action of an arc discharge plasma with a power of 10 kW for 5 minutes. After melting is complete, the melt is rapidly cooled by immersion in water to impart brittleness to the material, wherein the cooled material is characterised by a density of 3.85 g/cm 3 , consists of two phases forming a dense packing of grains with characteristically distributed dendritic or branched structures: the main matrix phase is characterised by an Al/Zr ratio of 6.8 by weight, into which colonies of a eutectic phase with an Al/Zr ratio of 0.94 by weight are uniformly incorporated. EFFECT: reduction in porosity and increase in strength of the ceramic product. 1 cl, 1 dwg, 1 tbl, 1 ex

Inventors

• Shekhovtsov Valentin Valerevich
• Sharafeev Sharif Mnirovich
• Bakshanskii Roman Iurevich
• Ulmasov Akhrorbek Bokhodirzhon ugli

Dates

Publication Date

20260507

Application Date

20250728

Claims (1)

1. A method for producing a ceramic product based on aluminum oxide Al 2 O 3 and zirconium oxide ZrO 2 , comprising the stages of preparing a charge containing 80 wt.% aluminum oxide and 20 wt.% zirconium oxide, melting it and then cooling it, characterized in that the melting of the charge is performed in a graphite melting chamber under the influence of an arc discharge plasma with a power of 10 kW for 5 minutes, after the end of melting the melt is quickly cooled by immersion in water to impart brittleness to the material, wherein the cooled material is characterized by a density of 3.85 g/cm 3 , consists of two phases that form a dense packing of grains with characteristically distributed dendritic or branched structures, the main matrix phase is characterized by an Al/Zr ratio equal to 6.8 by weight, into which colonies of the eutectic phase with an Al/Zr ratio equal to 0.94 by weight are uniformly included.

Description

The invention relates to ceramic technology, specifically to a method for producing high-strength and wear-resistant ceramic products based on aluminum oxide (Al 2 O 3 ) and zirconium oxide (ZrO 2 ), achieved by melting them in an arc discharge plasma environment. These products are used in the aircraft, mechanical engineering, medicine, chemical, and electrical industries to create components and coatings for use in conditions of increased wear, aggressive environments, and high temperatures. The closest in technical essence (prototype) is the method of synthesis of zirconium electrocorundum in a beam of fast electrons (Synthesis of zirconium electrocorundum in a beam of fast electrons / S.A. Gyngazov, I.P. Vasiliev, V.A. Boltueva, V.A. Vlasov // Bulletin of universities. Physics. - 2023. - Vol. 66, No. 9 (790). - Pp. 29-36. - DOI 10.17223/00213411/66/9/3). This method involves high-energy action with a power of 28 kW on a powder containing 80% aluminum oxide (Al 2 O 3 ) and 20% zirconium oxide (ZrO 2 ). Under the influence of an electron beam, the material undergoes partial melting, foaming and subsequent cooling, accompanied by the process of melt recrystallization. Significant drawbacks of the known method include the use of powerful electron sources (beam energy of 2 MeV, power of 28 kW) and the need to process small quantities of material. Furthermore, the formation of a large number of pores in the material reduces its strength and degrades its performance characteristics, thereby limiting the use of the resulting products. These factors make the method (prototype) insufficiently reliable and versatile for widespread industrial use. The objective of the proposed invention is to obtain a high-quality ceramic product based on aluminum oxide (Al 2 O 3 ) and zirconium oxide (ZrO 2 ) by melting in an arc discharge plasma environment, which makes it possible to eliminate the disadvantages of known analogues. To solve the stated problem and achieve a technical result, a method for producing a ceramic product based on aluminum oxide (Al 2 O 3 ) and zirconium oxide (ZrO 2 ) is proposed. The method involves preparing a batch containing 80% aluminum oxide and 20% zirconium oxide, then mixing the components in a ball mill, melting the batch in a graphite chamber under the influence of arc plasma, and pouring it into water to brittle the material, which is then ground and processed into a composite material. The method for producing a ceramic product based on Al 2 O 3 and ZrO 2 is as follows: the starting materials—aluminum oxide (Al 2 O 3 ) and zirconium oxide (ZrO 2 )—are mixed in a planetary ball mill in a ratio of 80:20% by weight. The resulting mixture is then placed in a graphite melting chamber, where it is melted under the influence of arc plasma until completely molten. The melt is then rapidly cooled by pouring it into water, which makes the material brittle for subsequent operations. As a result of the technological operations, a material with a density of 3.85 g/cm 3 is obtained, consisting of two phases: corundum grains (phase No. 1, Al/Zr ≈ 6.8), forming the main matrix, and a eutectic phase (phase No. 2, Al/Zr ≈ 0.9), distributed mainly along the grain boundaries in the form of a mesh or colony-like structure (Table 1). Micrograph of the obtained composite material demonstrating the phase distribution: dark rounded formations ~15 μm in size represent grains of the corundum matrix (phase No. 1), the light intergranular phase corresponds to the eutectic mixture Al 2 O 3 –ZrO 2 (phase No. 2), located mainly along the grain boundaries (Figure 1). Table 1. Elemental composition, wt.% WITHABOUTAlZrPhase #16.8236.6449.297.25Phase 27.3930.5629.8431.67 Example. Analytical-grade materials are used to produce a ceramic product based on aluminum oxide (Al 2 O 3 ) and zirconium oxide (ZrO 2 ). The components are mixed in a planetary ball mill at a ratio of 80:20 wt.% Al 2 O 3 : ZrO 2 . The resulting batch, weighing 50 grams, is poured into a graphite melting chamber, where it is melted under a 10 kW arc plasma discharge for 5 minutes. After melting is complete, the melt is rapidly cooled by pouring it into a container of water, which imparts a brittle structure to the material. According to electron microscopy data, the resulting composite has a density of 3.85 g/ cm3 and consists of two phases: the main matrix phase (No. 1) is characterized by an Al/Zr ratio of ≈ 6.8, into which colonies of the eutectic phase (No. 2) with an Al/Zr ratio of ≈ 0.9 are uniformly embedded. To produce a ceramic material with the specified geometric parameters, the melting products are ground to a fraction of ~5 μm in an IV-Micro vibratory grinder. The resulting powder is pressed at a pressure of 300 MPa and fired in a muffle furnace at a temperature of 1600°C with a holding time of 2 hours. The resulting fired ceramics are characterized by a density of 4.6 g/ cm3 and an open porosity of 7%.