KR100514342B1 - Abrasion resistance cemented carbide alloy - Google Patents

Abstract

The present invention relates to a cemented carbide alloy, and forms a process reaction with hard reinforced particles, nickel, and nickel by selecting any one or two or more from nitrides such as carbides such as tungsten carbide and chromium carbide, silicon nitride, and aluminum nitride. Consists of elements formed by selecting one or two or more among silicon, indium, and boron. The nickel and silicon, indium, and boron form a eutectic reaction, and thus the liquidus appearance temperature is lowered. Effectively lowering the bonding temperature required at the time will be able to manufacture a bonding material of a metal base material and a cemented carbide having excellent mechanical properties.

Description

Abrasion Resistance Cemented Carbide Alloy

The present invention relates to a wear resistant cemented carbide, and in particular, by lowering the liquid phase appearance temperature of the binder (Binder) excluding the reinforcing particles such as tungsten carbide (WC) or chromium carbide (Cr ₃ C ₂ ) of the components constituting the cemented carbide The present invention relates to a dean wear resistant cemented carbide having excellent reactivity with a metal even at low temperatures.

Generally, cemented carbide is composed of hard reinforcing particles such as tungsten carbide and chromium carbide, and a single metal such as nickel (Ni) and cobalt (Co), or a binder such as nickel alloy or cobalt alloy, and has high hardness and wear resistance. This has excellent mechanical properties.

Therefore, it is widely used in the form of joining with metal to parts such as tools such as cutting tools, tappets of vehicle engines, and rocker-arms that require wear resistance.

The cemented carbide is mixed with carbide powders such as tungsten carbide and chromium carbide and a single metal such as nickel and cobalt as a binder, or powders such as nickel alloy and cobalt alloy, and then sufficiently dried and molded into a constant shape. It is manufactured by the sintering process to maintain a certain time. At this time, the sintering temperature is usually made at a high temperature of 1350 ℃-1550 ℃.

The cemented cemented carbide is heated by heating above the temperature at which the liquid phase appears in the cemented carbide to react with the metal and reacts with the metal as the base metal. The joining temperature is performed within a temperature at which the properties of the steel do not change. Is preferred.

However, the liquid phase emergence temperature of currently used binders such as nickel and cobalt, or nickel alloys or cobalt alloys is approximately 1350 ° C or higher, which is close to the melting point (1450 ° C) of the base steel to be joined. There exists a possibility that the mechanical property of steel which is a base material may fall.

Accordingly, the present invention has been made to solve the above problems, and by adding various elements, the mechanical properties such as hardness and the like, while effectively reducing the liquid phase appearance temperature of the binder in the cemented carbide, that is, the bonding temperature, may be used for the conventional single metal such as nickel, cobalt, or the like. It is an object of the present invention to provide a wear resistant cemented carbide that does not degrade compared to cemented carbide using a binder of nickel alloy or cobalt alloy.

The wear-resistant cemented carbide of the present invention for achieving the above object is composed of hardened particles and binders selected by selecting any one or two or more from carbides such as tungsten carbide, chromium carbide, silicon nitride, aluminum nitride and the like. However, the binder is characterized in that consisting of nickel, and elements forming a process reaction with nickel.

In this case, the element forming the process reaction with nickel is characterized in that it is made by selecting one or two or more from silicon, indium, boron.

Wear-resistant cemented carbide of such a structure is required when joining to a bonded base material made of steel by reducing the liquid phase temperature by forming a process reaction in which elements formed by selecting one or two or more from nickel, silicon, indium, and boron as a binder are formed. Effectively lowering the bonding temperature is to be able to manufacture the bonding material of the metal base material and cemented carbide having excellent mechanical properties.

Hereinafter, with reference to the accompanying drawings, an embodiment of the present invention will be described in detail.

In the present invention, when added to nickel, a process reaction occurs in which the first and second solid phases precipitate in the liquid phase, and silicon, indium, and boron, which are elements that lower the liquid phase appearance temperature of the binder, are added to the nickel to form a binder. Abrasion resistant cemented carbide was prepared by mixing reinforcing particles such as tungsten carbide.

Example 1

As shown in FIG. 1, the process composition in the nickel-silicon alloy is 21.4 at% Si (process point 1143 ° C.), 29.8 at% Si (process point 1215 ° C.), 46 at% Si (process point 964 ° C.), 56.2 at% Si ( Process point 966 ℃), and the range of composition where process reaction occurs is 15.8at% Si-25at% Si, 27.9at% Si-33.3at% Si, 41at% Si-50at% Si, 50at% Si-66.7 at% Si range. The wear-resistant cemented carbide was prepared by mixing a cemented carbide with tungsten carbide or chromium carbide as reinforcing particles using a nickel-silicon alloy in a range of such a composition, followed by molding and sintering thereof.

In this embodiment, in order to produce a wear resistant cemented carbide having a low liquidus appearance temperature, the reinforced particles were made of tungsten carbide, and the binder was composed of a wear resistant cemented carbide composed of nickel and silicon as three components as shown in Table 1 below. In the manufacturing method, the raw material powder was mixed and molded and then sintered by maintaining it at 1150 ° C. for 1 hour, which is higher than 1143 ° C., which is a liquid phase appearance temperature in a Ni-Si state.

The hardness and sintered density of the wear-resistant cemented carbide prepared in this way were measured, and the appearance of liquid phase at 1150 ° C. was observed. In the compositions of Examples 1-5, the sintered density and hardness were lower than those of the compositions of Examples 1, 2, 3, and 4, and no appearance of liquid phase was observed.

Example 2

For the same purpose as in Example 1, the reinforcing particles were made of tungsten carbide, and the composition of the binder was prepared with three components, as shown in Table 2 below, containing a cemented carbide composed mainly of nickel and indium. In the manufacturing method, the raw material powder was mixed and molded, and then sintered by maintaining it at 915 ° C. higher than 910 ° C., which is a liquid phase appearance temperature in a Ni-In state diagram.

The hardness and sintered density of the wear-resistant cemented carbide prepared in this way were measured, and the appearance of liquid phase at 915 ° C. was observed. As a result, the sintered density and hardness were the highest in the composition of Example 2-3. In the composition of Example 2-5, the sintered density and hardness value were lower than those of the compositions of Examples 2-2, 3 and 4, and no appearance of liquid phase was observed.

Example 3

For the same purpose as in Example 1, the reinforcing particles were made of tungsten carbide, and the composition of the binder was shown in Table 3 below. The wear-resistant cemented carbide was prepared by adding boron to the nickel-silicon component.

As can be seen in Table 3, the composition of the binder, 8-12wt% silicon, 0.75-4.25wt% boron, the balance is made of nickel.

In the manufacturing method, the raw material powder was mixed and molded, and then sintered by maintaining it at 1100 ° C. for 1 hour, which is lower than 1143 ° C., which is a liquid phase appearance temperature of Ni-Si.

The hardness and sintered density of the wear-resistant cemented carbide prepared in this way were measured, and the appearance of liquid phase was observed at 1100 ° C. As a result, the sintered density and hardness were the highest in the composition of Example 3-3. It was confirmed that the temperature was lowered. On the other hand, in the compositions of Example 3-1 and Example 3-5, the sintered density and hardness values were lower than those of the Example 3-3 composition, and no appearance of liquid phase was observed.

Example 4

The alloy powder used in Example 3-3 was press-molded at a molding pressure of ² ton / cm ² to improve the molded body, and the molded product was placed on a bonded base material made of carbon steel (SM45C) at 200 ° C. under a load of 200 g. Bonding for 60 minutes. The sintered body had a hardness of HRA 86 or more, and the unbonded portion could not be observed at the junction interface. As a result of measuring the transfer strength of the bonded specimen, the shear strength of the bonded body was 400Kg / cm ² or more.

Many methods for forming wear-resistant members / metal joints to improve wear resistance for tools requiring high wear resistance such as cutting tools, valve lifters of diesel engines, tappets, cam followers and rocker arms are proposed. Although, according to the present invention, it is possible to manufacture a wear resistant cemented carbide that can be directly bonded while lowering the temperature at which the liquid phase reactive with the metal material appears in the cemented carbide to 1100 ° C. or less while minimizing the influence on the mechanical properties of the metal matrix.

1 is a state diagram of the Ni-Si system,

2 is a state diagram of the Ni-In system,

3 is a state diagram of a Ni-B system.

Claims (3)

In a cemented carbide comprising a hardened particle and a binder, selected from one or two or more of carbides such as tungsten carbide and chromium carbide, silicon nitride, and aluminum nitride, The cemented carbide is composed of a 40wt% binder, the remainder is composed of hardened particles, the binder is 88 ~ 89wt% nickel, and wear-resistant cemented carbide, characterized in that 11 to 12wt% of silicon forming a process reaction with nickel . In a cemented carbide comprising a hardened particle and a binder, selected from one or two or more of carbides such as tungsten carbide and chromium carbide, silicon nitride, and aluminum nitride, The cemented carbide is composed of a 40wt% binder, the remainder is composed of hardened particles, the binder is 55 ~ 64wt% nickel, wear-resistant cemented carbide, characterized in that consisting of 36 ~ 45wt% indium forming a process reaction with nickel . In a cemented carbide comprising a hardened particle and a binder, selected from one or two or more of carbides such as tungsten carbide and chromium carbide, silicon nitride, and aluminum nitride, The cemented carbide is composed of 40wt% binder, the balance is composed of hardened particles, the binder is 8.25 ~ 11.75wt% silicon forming a process reaction with nickel, 0.75 ~ 4.25wt% boron, the balance is nickel Abrasion resistant cemented carbide, characterized in that made.