RU2230811C1 - Nickel-based alloy for denture carcass - Google Patents

Abstract

FIELD: stomatology.

SUBSTANCE: invention relates to nickel-based alloy used for molding metallic carcasses of fixed metalloceramic dentures. Invention, in particular, provides nickel-based alloy containing, wt %: carbon 0.001-0.03, silicon 0.5-2.5, manganese 0.001-0.2, chromium 22.0-25.0, molybdenum 9.0-11.0, vanadium 0.15-0.5, iron 0.01-1.0, cobalt 0.01-1.0, one or more rare-earth element (yttrium allays one of them) 0.2-1.0, and additionally tungsten 0.03-3.0, niobium 0.5-2.0, and tantalum 0.03-2.5, provided that sum of concentrations [Cr]+[Mo]+[W]+[V]+[Nb]+[Ta]=32-44 wt % and ratio

.

EFFECT: improved strength and plastic characteristics and increased adhesion of metal-ceramic connection.

2 cl, 2 tbl, 10 ex

Description

The invention relates to the field of metallurgy, in particular to the development of nickel-based alloys used for casting metal frames of fixed ceramic-metal dentures (crowns, bridges, etc.).

In dentistry, nickel alloys containing chromium, molybdenum, silicon and other elements are widely used for the manufacture of cast dental prosthesis frames. These alloys must meet established biomedical and sanitary-hygienic standards and have the necessary combination of properties that determine the quality and performance of a ceramic-metal prosthesis.

The casting properties of the alloy should provide defect-free thin-walled castings with specified geometric dimensions. The alloy should be well processed with an abrasive tool and polished, have high adhesion strength and close thermal coefficient of linear expansion with the applied ceramic mass, and not change color when firing the prosthesis.

To ensure the structural strength of the prosthesis, the yield strength (σ ₀₂ ) and elongation (δ _s ) of the alloy during tensile testing of specimens should be at least 250 MPa and 3%, respectively (according to the international standard GOST R 51 767).

Closest to the proposed technical solution in essence is an alloy based on nickel for dental prosthesis frames (RF patent No. 2009243 of 03/11/92), containing components in the following ratio, wt.%:

carbon 0.005-0.06

silicon 1.5-2.5

Manganese 0.001-0.3

chrome 22.0-25.0

vanadium 0.15-0.30

molybdenum 9.0-11.0

one or more

REM elements 0.2-1.2

iron 0.1-3.0

cobalt 0.1-4.0

nickel rest

The alloy in the cast state has the following characteristics: yield strength (σ ₀₂ ) 330-380 MPa; elongation (δ _s ) 4.0-8.5%, hardness HB 1700-1850; thermal coefficient of linear expansion (TEC) in the temperature range of 20-500 ° C - 13.8-13.9 × 10 ^-6 K ^-1 ; tensile strength (σ _in ) 500-560 MPa.

This alloy is widely used in domestic orthopedic dentistry, but is not strong enough to be used as a material in the manufacture of complex ceramic-metal frames of long bridge prostheses. In addition, it does not have sufficient and stable ductility.

The technical result from the use of the present invention is the production of a nickel alloy for casting metal-ceramic prostheses with high strength and good stable ductility.

The technical result is achieved in that the nickel-based alloy containing carbon, silicon, manganese, chromium, molybdenum, iron, cobalt, vanadium, one or more rare earth elements, tungsten, niobium and tantalum are additionally introduced in the following ratio of components in wt.%:

carbon 0.001-0.03

silicon 0.5-2.5

Manganese 0.001-0.2

chrome 22.0-25.0

molybdenum 9.0-11.0

vanadium 0.15-0.5

tungsten 0.03-3.0

niobium 0.5-2.0

tantalum 0.03-0.3

iron 0.01-1.0

cobalt 0.01-1.0

one or more rare earths 0.2-1.0

nickel rest

, где [Cr]+[Mo]+[W)+[V]+[Nb]+[Ta] и [С] - концентрации хрома, молибдена, вольфрама, ванадия, ниобия, тантала и углерода соответственно, мас.%. Сплав может содержать в качестве одного из редкоземельных элементов иттрий в количестве 0,2-1,0%.the sum of the concentrations of chromium, molybdenum, tungsten, vanadium niobium and tantalum is [Cr] + [Mo] + [W] + [V] + [Nb] + [Ta] = 32-44 and when the condition for the ratio of the sum of the concentrations of vanadium is met , niobium and tantalum to carbon concentration

where [Cr] + [Mo] + [W) + [V] + [Nb] + [Ta] and [C] are the concentrations of chromium, molybdenum, tungsten, vanadium, niobium, tantalum and carbon, respectively, wt.%. The alloy may contain yttrium in the amount of 0.2-1.0% as one of the rare earth elements.

происходит снижение показателей пластичности, особенно после нанесения керамического покрытия и обжига. Сплав может содержать один или более редкоземельных элементов или в качестве одного из редкоземельных элементов - иттрий в количестве 0,2-1,0%. Иттрий является аналогом РЗМ и оказывает такое же действие на свойство сплава, но несколько повышает коррозионную стойкость материала, поэтому введение иттрия в ряде случаев целесообразно. Изменение содержания РЗМ и иттрия практически не отражается на основных характеристиках, но расширяет возможности регулирования технологических технологических свойств сплава. При уменьшении суммарного содержания этих элементов в сплаве менее 0,2% значительно уменьшаются адгезивные свойства, а при увеличении их концентрации более 1,0% сплав охрупчивается и относительное удлинение сплава становится меньше допустимого. Стандартом (ГОСТ Р 51 767) предела.The introduction of tungsten, niobium and tantalum into the alloy provides an increase in the strength of the alloy (σ _c ) and its fluidity (δ ₀₂ ), relative elongation (δ _s ) and adhesive strength of the ceramic-metal compound while maintaining the remaining properties at the level characteristic of the known alloy. The lower limit of the content of tungsten, niobium and tantalum is due to the fact that when they are introduced in amounts less than 0.3%, 0.5% and 0.02%, respectively, the strength properties decrease. At tungsten, niobium, and tantalum concentrations above 3.0%, 2.0%, and 2.5%, respectively, the alloy is embrittled. In a similar way, the mechanical properties of the metal change when the balance of the total content of reinforcing elements is disturbed (if the sum of [Cr] + [Mo] + [W] + [V] + [Nb] + [Ta] less than 32, the strength properties drop, with the sum exceeding 44 - the metal becomes brittle). If the conditions are not met

ductility decreases, especially after ceramic coating and firing. The alloy may contain one or more rare earth elements or, as one of the rare earth elements, yttrium in an amount of 0.2-1.0%. Yttrium is an analogue of rare-earth metals and has the same effect on the property of the alloy, but slightly increases the corrosion resistance of the material, so the introduction of yttrium in some cases is advisable. The change in the content of rare-earth metals and yttrium has practically no effect on the main characteristics, but it expands the possibilities of regulating the technological technological properties of the alloy. With a decrease in the total content of these elements in the alloy of less than 0.2%, the adhesive properties significantly decrease, and with an increase in their concentration of more than 1.0%, the alloy becomes brittle and the elongation of the alloy becomes less than acceptable. Standard (GOST R 51 767) limit.

The invention is illustrated by examples. Alloys were smelted and cast onto measured billets in a vacuum induction furnace. The obtained billets were remelted in a high-frequency foundry and liquid metal was poured into hot ceramic molds by the centrifugal method according to the technology adopted in dental clinics.

The chemical composition of the proposed and known alloys is shown in table 1. Table 2 shows the properties of these alloys.

The above data indicate that the proposed alloy has increased strength and plastic properties, high adhesion strength of the ceramic-metal compound.

Claims (2)

1. Nickel-based alloy for dental prosthesis frames containing carbon, silicon, manganese, chromium, molybdenum, iron, cobalt, vanadium, one or more rare earth elements, characterized in that it additionally contains tungsten, niobium and tantalum in the following ratio of components , wt.%: Carbon 0.001-0.03 Silicon 0.5-2.5 Manganese 0.001-0.2 Chrome 22.0-25.0 Molybdenum 9.0-11.0 Vanadium 0.15-0.5 Tungsten 0.03-3.0 Niobium 0.5-2.0 Tantalum 0.03-2.5 Iron 0.01-1.0 Cobalt 0.01-1.0 One or more rare earths 0.2-1.0 Nickel Else the sum of the concentrations of chromium, molybdenum, tungsten, vanadium, niobium and tantalum is [Cr] + [Mo] + [W] + [V] + [Nb] + [Ta] = 32-44, and if the condition of the ratio concentrations of vanadium, niobium and tantalum to carbon concentration

where [Cr], [Mo], [W], [V], [Nb], [Ta] and [C] are the concentrations of chromium, molybdenum, tungsten, vanadium, niobium, tantalum and carbon, respectively wt.%. 2. The alloy according to claim 1, characterized in that the alloy contains yttrium as one of the rare earth elements.