KR20030012349A - Bonding process of Al flange/Bronze wheel containing diamond for precision cutting - Google Patents

Abstract

PURPOSE: A method for bonding diamond wheel for precision cutting with aluminum flange using bronze alloy based binder is provided to suppress reduction of bonding strength by bonding the diamond wheel for precision cutting with the aluminum flange using solid state diffusion bonding, thereby minimizing intermetallic compounds generated on the bonding interface. CONSTITUTION: The method for bonding diamond wheel for precision cutting with aluminum flange using bronze alloy based binder is characterized in that solid state diffusion bonding is performed in the temperature range of 400 to 560 deg.C under an atmosphere of inert gas such as Ar and N2 and at a pressure of 10 to 40 MPa for a maintenance time period of 60 minutes or less, wherein the diamond wheel made of bronze is manufactured by simultaneously adding 10 wt.% or less of each of Ni and Co as a binder to bronze powder in which 10 wt.% of Sn is added to Cu, and sintering bronze powder to which 3 to 15 vol.% of diamond is added, the binder is chromium (Cr), the bonding atmosphere is reductive atmosphere (H2), an atmosphere of inert gas (Ar, He and N2) or a vacuum atmosphere, thickness of a reaction layer of the bonding interface is controlled to 150 micrometers or less, the bonding temperature is formed under a pressure of 10 to 40 MPa for 10 to 60 minutes, and the solid state diffusion bonded material is cooled at a cooling rate of 50 deg.C/sec or less.

Description

Bonding process of Al flange / Bronze wheel containing diamond for precision cutting}

The present invention relates to a bonding method used to obtain excellent bonding strength between a bronze alloy wheel and an aluminum flange bonded diamond added, in particular, between the metal generated in the junction interface by solid phase diffusion bonding under a predetermined temperature and atmosphere A conjugation method for inhibiting a compound.

Conventionally, as a method of diamond bonding of a cutting wheel in which diamonds are plated on aluminum flanges, a method of electrodeposition by electroplating or electroless plating has been widely used.

However, there are some problems as follows.

First, a cutting wheel in which diamond is plated on an aluminum flange by electrodeposition is insufficient in bonding strength, so that diamond is separated when processing a workpiece having high hardness, such as a silicon wafer.

Second, the separation of diamond from the cutting wheel occurs particularly severely, especially when the polymer-based chemical is coated on the surface of the silicon wiper.

Third, the electrodeposited diamond is very thin and cannot be used for a long time.

On the other hand, since the cutting wheel (Wheel) rotates at high speed during cutting and grinding, the bonding force between the diamond sintered body and the flange (Flange) is important. In general, the bonding between the diamond sintered body and the flange is carried out by melt bonding, electrodeposition, or laser method, but defects in the bonding interface during bonding and residual stress due to thermal expansion coefficient in the bonding interface during cooling are generated. Destruction occurs.

Therefore, in order to develop a joint with high joint strength and reliability, the amount of residual stress generated in the joint should be minimized. In order to simplify the work process, development of joint design technology is required, and a new joint method is required to secure the joint reliability. Should be used

The solid phase diffusion bonding method is capable of bonding with dissimilar metals having different physical properties, and unlike conventional melt bonding (brazing, soldering, and laser methods), it is possible to obtain excellent bonding characteristics because there is little risk of changing the microstructure of the joint.

Therefore, it is necessary to analyze the bonding interface between the bonding material and the support (shank part) by performing solid-phase bonding with aluminum (Al) used as a flange by adding diamond to the bronze alloy to which nickel chromium cobalt is added.

In general, it has been reported that the bonding of bronze-based alloys with aluminum produces intermetallic compounds (such as CuAl Cu 2 Al Cu 9 Al 4) which adversely affect the mechanical properties at the joint interface and these occur during bonding.

In order to minimize the presence of intermetallic compounds, the solid-state diffusion bonding method is performed under the fusion welding of the two base materials, compared to the melt bonding method (soldering, brazing, laser method). It can minimize the breakdown of the bonding interface due to the coefficient of thermal expansion of different dissimilar metals.

An object of the present invention to solve the above problem is to bond the bonding interface of the diamond alloy-bonded alloy wheel and the aluminum flange bonded with bronze and aluminum, wherein the diamond is fixed to the displacement (Dislocation) movement It improves the mechanical strength by acting as a pin, and minimizes the intermetallic compounds that can occur at the bonding interface by inhibiting the decrease of the bonding strength by joining by solid phase diffusion method.

In addition, another object of the present invention is to provide a method of joining a bronze alloy-based wheel and an aluminum flange to which diamond is added, which can simplify the work process, thereby reducing the production cost and the number of processes.

The present invention is to analyze the interface between the bonding material and the support (shank part) by performing a solid-phase bonding to aluminum (Al) used as a flange by adding diamond to the bronze alloy added nickel nickel cobalt, respectively. do.

Figure 1 is a graph showing the change in thickness of the intermetallic compound generated in the bonding interface after the diffusion bonding the diamond alloy bronze alloy wheel and the aluminum flange according to the present invention according to the bonding time.

2 is a graph showing the thickness of the reaction layer after diffusion bonding the aluminum flange while increasing the amount of nickel, chromium, and cobalt added to the diamond-based bronze alloy wheel according to the present invention.

3 is a graph showing the distribution of hardness values at the interface between the diamond alloy-added bronze alloy wheel and the aluminum flange according to the present invention.

The present invention to achieve the above object is achieved by a solid-state diffusion bonding method of aluminum alloy with a purity of 99% or more and a bronze alloy wheel with nickel and chromium cobalt added to each other less than 10%.

At this time, the thickness of the bronze-based alloy wheel and aluminum is preferably 2 to 20mm or less and the joint interface is processed to 45 ° or less, respectively, to secure the maximum joint area of the joint interface.

In addition, the bonding temperature is carried out at a temperature of 400 to 560 ℃ in consideration of the melting point of aluminum to apply a pressure of around 30MPa in order to control the reaction layer of the bonding interface to 150㎛ or less, the bonding temperature is bonded for 5 to 60 minutes And it is achieved by a solid-phase diffusion bonding method comprising the step of cooling the conjugate of the bronze-based alloy and aluminum at a rate of no cooling or 50 ℃ / sec or less.

At this time, the bonding step may be performed in an inert gas (N2, Ar, etc.) or reducing component (H2) instead of vacuum.

In addition, the bonding of the bronze-based alloy and aluminum of the present invention is different in thermal expansion coefficient, so that the bonding is performed in the solid state below the melting point of the two materials to be joined.

Diamond, chromium, nickel, cobalt added to the bronze-based alloy of the present invention has the advantage of being dissolved or precipitated in the bronze-based alloy to improve the mechanical properties of the bronze-based alloy, so that the diamond does not escape from the bronze-based alloy .

In addition, chromium, nickel, and cobalt elements in the bronze-based alloy do not react with the resin-type compound during cutting of the silicon wiper to which the polymer or resin-type compound is attached, thereby achieving a highly precise machining surface.

The present invention is capable of bonding with dissimilar metals having different physical properties, and unlike the conventional melt bonding (brazing, soldering, laser method), there is little risk of changing the microstructure of the joint, so that the solid-state diffusion bonding method is obtained. to provide.

Therefore, in the present invention, the bonding interface between the binder and the support (shank part) can be analyzed by adding a diamond to the bronze alloy to which nickel chromium cobalt is added and performing solid phase bonding with aluminum (Al) used as a flange.

In general, when a bronze alloy is bonded with aluminum, it is reported that intermetallic compounds (CuAl Cu2Al Cu9Al4, etc.) are generated at the bonding interface, which adversely affects mechanical properties, and these occur during the joining, and minimize the presence of intermetallic compounds. In contrast to the melt bonding method (soldering, brazing, and laser method), the solid-state diffusion bonding method is performed under the welding of two base materials, so that the change of coagulation structure and intermediate product that may occur during the cooling process is minimized, It is possible to minimize the fracture of the joint interface due to the coefficient of thermal expansion.

Hereinafter, embodiments of the present invention will be described with reference to the accompanying drawings.

1 of the accompanying drawings shows the relationship between the bonding time and temperature obtained in the present invention and the thickness of the reaction layer. As shown in this graph, the bonding interface was completely formed when the bonding temperature was bonded at 560 ℃ for 20 minutes, but the reaction layer of 16 µm thickness was observed on the bonding interface. The thickness of was increased to 59 μm.

When the bonding temperature was carried out at 500 ° C. for 20 minutes, the thickness of the reaction layer was very narrow, but the joint interface was not completely formed and local unbonded sites and cracks were found.

Figure 2 of the accompanying drawings is a graph showing the thickness of the reaction layer produced by diffusion bonding the aluminum flange when each nickel chromium cobalt is added to the bronze alloy added with diamond for 20 minutes at 560 ℃ obtained in the present invention.

In the graph, as the amount of nickel chromium cobalt increases, the thickness of the reaction layer generated at the bonding interface is extremely thin. This is because nickel chromium cobalt addition element and diamond in bronze alloy partially prevent the diffusion movement of atoms.

Figure 3 of the accompanying drawings is a graph showing the distribution of hardness value at the interface of the bonding of the aluminum alloy and the bronze alloy wheel with the addition of diamond according to the present invention.

In the graph, when nickel, chromium, and cobalt were added, the hardness value increased at the interface compared with the specimen without the added element. The nickel and cobalt solid solution in bronze were dissolved in the reaction layer due to the solid solution effect. The hardness value was slightly lower than the hardness value in the reaction layer of the chromium-added bronze-aluminum interface.

The present invention has the advantage that diamond, chromium, nickel, cobalt added to the bronze-based alloy is dissolved or precipitated in the bronze-based alloy to improve the mechanical properties of the bronze-based alloy and prevent the diamond from being separated from the bronze-based alloy. .

In addition, chromium, nickel, and cobalt elements in the bronze-based alloy do not react with the resin-type compound during cutting of the silicon wiper to which the polymer or resin-type compound is attached, thereby achieving a highly precise machining surface.

In addition, the present invention is to develop a joint with high joint strength and reliability, minimize the amount of residual stress generated in the joint, and is suitable for the development of the design technology of the joint to simplify the work process, solid phase diffusion bonding method that ensures the reliability of the joint It is possible to bond with dissimilar metals having different physical properties, and unlike conventional melt bonding (brazing, soldering, and laser methods), there is little risk of changing the microstructure of the joint, and thus excellent bonding characteristics are obtained.

This effect allows the present invention to analyze the bonding interface between the binder and the support (shank part) by performing a solid-phase bonding with aluminum (Al) used as a flange by adding diamond to the bronze alloy to which nickel chromium cobalt is added. It also has side effects.

In general, when a bronze-based alloy is bonded to aluminum, intermetallic compounds (CuAl Cu2Al Cu9Al4, etc.) are generated during the bonding, which adversely affects mechanical properties, so that the melt bonding method (soldering, brazing, laser) is minimized. Compared to the method), the solid-state diffusion bonding method of the present invention is performed under the fusion of the two base materials, thereby minimizing the change of coagulation structure and the formation of intermediate products that may occur during the cooling process, It can also minimize destruction.

Claims (9)

In the method of joining a diamond wheel for cutting and an aluminum flange using a bronze alloy-based binder, Diamond wheel for cutting using bronze alloy-based binder, characterized in that the solid phase diffusion bonding under inert gas atmosphere (Ar, N2, etc.) and 10-40MPa pressure for a holding time of less than 60 minutes in the temperature range of 400 ℃ -560 ℃ Joining method of aluminum flange. The method of claim 1, The bronze diamond wheel, 10% (mass%) of nickel (Co) or cobalt (Co) is added to the bronze powder containing 10% (mass%) of tin (Sn) to copper (Cu). A method of joining a diamond wheel and an aluminum flange for cutting using a bronze alloy-based binder, characterized in that it is manufactured by sintering a bronze powder having 3 to 15 vol% of diamond added thereto. The method of claim 1, Joining method of cutting diamond wheel and aluminum flange using a bronze alloy-based binder, characterized in that the binder is chromium (Cr). The method of claim 1, Joining atmosphere is a reducing component atmosphere (H2), characterized in that the joining method of the diamond wheel and aluminum flange for cutting using a bronze alloy-based binder. The method of joining a diamond wheel for cutting and an aluminum flange using a bronze alloy-based binder according to claim 1, wherein the bonding atmosphere is an inert gas (Ar, He, N2, etc.) atmosphere. The method of joining a diamond wheel for cutting and an aluminum flange using a bronze alloy-based binder according to claim 1, wherein the bonding atmosphere is a vacuum atmosphere. The method according to any one of claims 1 to 6, A method of joining a diamond wheel for cutting and an aluminum flange using a bronze alloy-based binder, characterized in that the reaction layer thickness of the joining interface is controlled to 150 μm or less. The method according to any one of claims 1 to 6, A joining method for cutting diamond wheels and aluminum flanges using a bronze alloy-based binder, characterized in that the joining temperature is made under a pressure of 10 to 40 MPa for 10 to 60 minutes. The method according to any one of claims 1 to 6, A method of joining a diamond wheel for cutting and an aluminum flange using a bronze alloy binder, characterized by cooling at a rate of 50 ° C / sec or less.