RU-2861623-C1 - METHOD FOR MANUFACTURING MIXED OXIDE-NITRIDE-CARBIDE CUTTING CERAMICS

RU2861623C1RU 2861623 C1RU2861623 C1RU 2861623C1RU-2861623-C1

Abstract

FIELD: chemical industry. SUBSTANCE: invention relates to a method for manufacturing a cutting insert from mixed oxide-nitride-carbide ceramics. A mixture of aluminium oxide and titanium nitride is calcined at a temperature of 1850-1950°C. The calcined mixture is subjected to fine vibration grinding in a vibration unit for 3.6-4.8 hours until 90-95% of grains with a size of 0.6-0.8 mcm are obtained and dried. After drying, tungsten carbide and niobium carbide are introduced into the vibration-ground mixture and mixed until they are uniformly distributed throughout the volume and an aqueous suspension is formed. Deoxidising catalyst additives in the form of magnesium oxide MgO, silicon oxide SiO 2 , calcium oxide CaO and sodium oxide Na 2 O are introduced into the resulting aqueous suspension and subjected to spray drying to obtain a mixture. The resulting mixture is then pressed to form a cutting insert, which is sintered at a temperature of 4100-4300°C and subjected to short-term annealing at a temperature of θ=1850-1950°C with a hold of 12.0-17.0 minutes. The sintered cutting insert is subjected to mechanical processing to obtain a surface roughness of the faces equal to Ra=0.04-0.06 mcm. The mixed oxide-nitride-carbide ceramics for manufacturing the cutting insert contains refractory components in the following ratio, mas.%: aluminium oxide Al 2 O 3 - 60, titanium nitride TiN - 15, tungsten carbide WC - 15 and niobium carbide NbC - 10. EFFECT: increasing the strength, hardness and wear resistance of inserts made of mixed oxide-nitride-carbide cutting ceramics. 1 cl, 1 tbl, 1 ex

Inventors

Puchkin Vladimir Nikolaevich
Burlakova Viktoriya Eduardovna
VARAVKA VALERIJ NIKOLAEVICH
Kudryakov Oleg Vyacheslavovich
LAPSHIN VIKTOR PETROVICH
Turkin Ilya Andreevich
KORNIENKO VLADIMIR GAVRILOVICH

Dates

Publication Date: 20260506
Application Date: 20250930

Claims (2)

A method for manufacturing a cutting insert from mixed oxide-nitride-carbide ceramics, characterized in that a mixture of aluminum oxide and titanium nitride is calcined at a temperature of 1850-1950 °C, the calcined mixture is subjected to fine vibration grinding on a vibration unit for 3.6-4.8 hours until up to 90-95% of grains with a size of 0.6-0.8 μm are obtained and dried, after drying, tungsten carbide and niobium carbide are introduced into the vibration-ground mixture and mixed until they are uniformly distributed throughout the volume and an aqueous suspension is formed, deoxidizing additives of catalysts in the form of magnesium oxide MgO, silicon oxide SiO 2 , calcium oxide CaO and sodium oxide Na 2 O are introduced into the resulting aqueous suspension and subjected to spray drying to obtain a mixture, after which the resulting mixture is pressed to form a cutting plate, which is subjected to sintering at a temperature of 4100-4300°C and short-term annealing at a temperature of θ=1850-1950°C with a holding time of 12.0-17.0 min, after which the sintered cutting plate is subjected to mechanical processing to obtain a roughness of the edges equal to Ra=0.04-0.06 μm, while the mixed oxide-nitride-carbide ceramics for the manufacture of the cutting plate contains refractory components in the following ratio, wt.%:
aluminum oxide Al 2 O 3 60 titanium nitride TiN 15 tungsten carbide WC 15 niobium carbide NbC 10

Description

The invention relates to the production of super-hard, high-strength, wear-resistant ceramic plates for equipping cutting tools for processing hard-to-machine steels and alloys, as well as high-strength white and gray cast irons SCh18, SCh20, etc. on metalworking machines. Known (GOSTs for cutting ceramics VOK-60 GOST 25003-81; VOK-63, B-3, VOK-73 GOST 19043-80). Known (methodologies) Monographs [1, 2, 3]. Here is an example of manufacturing standard plates. Domestically produced oxide-carbide cutting ceramics of the VOK-60, VOK-63, V-3, and VOK - 73 grades (mixed, "metallic," and "black") consist of Al2O3 oxide (up to 60%), TiC (up to 20-40%), ZrO2 (up to 20-40%), and other refractory metal carbides with certain alloying additives. Oxide-carbide ceramic inserts are produced by hot pressing in graphite molds. The production of standard plates begins with grinding the components of the mixture and preparing the charge. Next, the components are mixed, the prepared charge is wet-milled, dried, dosed, and hot pressed. Once pressing is complete, the mold is disassembled, the pressed blanks are removed, and they are sent for machining. The quality and stability of standard cutting inserts are largely determined by the following factors: the content of titanium carbide and aluminum oxide in the initial charge, the time of grinding the mixture, the temperature and holding time during hot pressing, and the pressing pressure. Hardness of plates at the delivery stage, HRA 92…94. The durability of standard plates at the delivery stage when cutting difficult-to-machine and heat-resistant steels of grades 12X18H10T, 14X17H2, etc. is 60 min. Mechanical properties of standard plates at the delivery stage: bending stress σ = 600 MPa; density 4.2 g/cm3; grain size 2…3 μm; hardness HRA 92… 94. A method for producing a ceramic plate for a cutting tool is known [4], which includes calcining alumina containing α-Al 2 O 3 and γ-Al 2 O 3 , vibratory grinding, enrichment, drying to obtain aluminum oxide modification: α-Al 2 O 3 , mixing it with silicon oxide, titanium carbide, tungsten carbide, chromium oxide, nickel, molybdenum, niobium and cobalt, plasticization and hot pressing to obtain a pressed plate, sintering, annealing with holding for 5-10 minutes in the region of the temperature maximum and its mechanical processing. A method for producing a ceramic plate for a cutting tool is known [5], which includes calcining alumina, vibratory grinding, enrichment, and drying to obtain aluminum oxide of the α-Al 2 O 3 modification. The resulting aluminum oxide is mixed with alloying components in the following ratio of components, wt.%: aluminum oxide 58-60, titanium carbide 30-32, chromium oxide 5-7, nickel 2-3, molybdenum 1-2. Next, plasticization and hot pressing are carried out to obtain a pressed plate, sintering and annealing with a hold of 5-10 minutes in the region of the temperature maximum of the obtained plate and its mechanical processing. A known method for producing a ceramic plate for a cutting tool [6] includes calcining alumina, vibratory grinding, enrichment, and drying to obtain aluminum oxide of the α-Al 2 O 3 modification. The resulting aluminum oxide is mixed with alloying components in the following ratio of components, wt.%: aluminum oxide 28-30, silicon oxide 28-30, titanium carbide 18-20, tantalum carbide 8-10, tungsten carbide 8-10. Next, plasticization and hot pressing are carried out to obtain a pressed plate, sintering and annealing with a hold of 5-10 minutes in the region of the temperature maximum of the obtained plate and its mechanical processing. There are known plates made of oxide-carbide cutting ceramics of the brands VOK-60, VOK-63, VOK-73, VO-3 and others, produced by our domestic industry: VOK-60 GOST 25003-81 [7]; VOK-71 GOST 19043-80 [8]. The closest analogue is the oxide-carbide cutting ceramics VOK-60 consisting of aluminum oxide Al 2 O 3 (up to 60%), TiC (up to 20%), ZrO 2 (up to 20%) with some alloying additives: MgO and ZrO 2. The starting material for the production of oxide and oxide-carbide ceramics in the Russian Federation is technical alumina, which is a mixture of two modifications: γ-Al 2 O 3 with a density of 3.65 g/cm 3 and α-Al 2 O 3 with a density of 3.96 g/cm 3 ([8] 15 - 22). The disadvantage of aluminum oxide-based oxide-carbide cutting ceramics is brittleness, low wear and corrosion resistance, temperature resistance, heat resistance and low durability of plates, especially when processing difficult-to-machine steels, alloys and materials. A similarly similar method is the production of cutting ceramics, where plates made of mixed oxide-carbide ceramics are produced by hot pressing in graphite molds. These plates are used for machining malleable and chilled cast irons, as well as heat-treated, case-hardened, and HRC 30-65 steels (see Table 1.4 [8] pp. 15-22). The main disadvantages of this method are: 1. This process is more labor-intensive than the process of producing