TW202015844A - Metal bonding process capable of achieving the effects of high heat dissipation, lightweight and wear resistance - Google Patents

Abstract

The present invention relates to a metal bonding process, which includes: performing a quenching process on at least one first metal piece and then cooling the at least one first metal piece to a normal temperature; adding flux and welding medium to a joint position of the first metal piece and a second metal piece; putting the first metal piece and the second metal piece against each other, and simultaneously heating the first metal piece and the second metal piece to a temperature lower than a critical liquefaction temperature of the second metal piece, wherein the temperature is also used as a heating temperature of the first metal piece in tempering process; using the heated flux to remove a first oxide layer on the surface of the first metal piece and a second oxide layer on the surface of the second metal piece; and at the moment of detachment, the welding medium entering the detachment position to directly connect the first metal piece with the second metal piece. Accordingly, the first metal piece with high hardness and the second metal piece with high thermal conductivity and low specific gravity are bonded in a large contact area, so that the characteristics of the two metals are complementary to each other to achieve the effects of high heat dissipation, lightweight and wear resistance.

Description

Metal bonding process

The present invention is to provide a metal bonding process, especially a metal joint of a first metal part with high hardness and a second metal part with high thermal conductivity and low specific gravity, so that the overall metal characteristics are complementary, and a high heat dissipation effect is achieved. The process of metal joining with wear resistance and light weight characteristics.

Press, disc brake, also known as disc brake or disc brake, is a brake device widely used in various types of vehicles and industrial machinery. The disc brake device is mainly composed of a brake disc mounted on the axle and rotating coaxially with the wheel, a caliper that spans on both sides of the brake disc like a caliper, and a brake pad that presses the brake disc during braking, thereby making the brake The friction between the disc and the brake disc produces the effect of braking and deceleration braking.

In the past, in order to improve vehicle driveability and reduce fuel consumption, the rim of the wheel was changed from low-carbon steel to aluminum alloy, because the specific gravity of steel is 7.87g/cc, and the specific gravity of aluminum alloy is 2.7g/cc. On the premise of a substantial increase in specific strength, weight reduction can be effectively achieved.

To complete the metal joining of aluminum and stainless steel, we must first understand that the physical properties of aluminum and stainless steel are quite different (including the difference in density and melting point), and because there is almost no opportunity to join them by liquid phase welding, so basically All use mechanical methods as the joining means to form the composite material, and the available methods include friction welding, rolling joining, diffusion joining and screw locking. Among them, friction welding must be achieved under the condition that the contact surface is not in contact with the fresh oxidizing atmosphere, and the two metals can be deformed by the friction heating under the relative rotary motion to cause the deformation of the contact surface. The contact area is large, the operation method is strict, and the process cost High; the principle of rolling bonding is similar to friction welding, but it is a method that requires higher flatness of the metal surface. It is not suitable for mechanically shaped disc brake discs; diffusion bonding (diffusion bonding) and other non-melting Welding of the metal (Welding) requires the removal of the oxide layer of aluminum and stainless steel. However, the biggest common point between aluminum and stainless steel is that the oxide layer on the surface belongs to a high melting point immobile oxide layer, and the oxidation of the oxide layer is completed almost instantly However, the metal oxide is not a metal, so the oxide will become an obstacle to interdiffusion between metals, so that diffusion bonding cannot be achieved.

Not only the disc brake disc, but also the need to join two different metals in different fields, When the two metals are joined by pressure bonding by mechanical bonding, as shown in the first figure, it is a macro view of the conventional metal joint surface of the composite material. The first metal 91 and the second metal 92 look like the naked eye It has been completely bonded. In fact, because of the different amounts of deformation of the metal, the gap 93 of the metal joint surface is extremely large, so that the size of the contact area between the metals cannot provide effective heat conduction, even if the thermal conductivity of the second metal 92 is much greater than that of the first metal The thermal conductivity of 91 is still too small due to the effective contact area between the two, and the heat energy accumulated by the friction cannot be transferred to the second metal 92; when the two metals are connected by the welding material, although the melting welding material 94 can be used to fill the two The gap 93 between the metals (as shown in the second figure is a microscopic schematic view of the metal joint surface of the conventional composite material), but the welding material 94 is only connected to the oxide layer 95 on the surface of the first metal 91 and the second metal 92, It is not helpful for heat conduction.

Therefore, how to complement the characteristics of the two metals under the premise of light weight and high thermal conductivity to solve the above-mentioned problems and defects, that is, the inventors of the present invention and related manufacturers engaged in this industry are desperate to study and improve Where the direction is.

Therefore, in view of the above-mentioned deficiencies, the inventor of the present invention collected relevant data, evaluated and considered through multiple parties, and based on years of experience accumulated in this industry, through continuous trial work and modification, he designed this high-hardness first The inventor of the invention is a metal jointing process of a metal part and a second metal part with high thermal conductivity and low specific gravity to complement the overall metal characteristics and achieve high heat dissipation, wear resistance and lightweight characteristics.

The main purpose of the present invention is to cooperate with the removal action of the first oxide layer and the second oxide layer on the surfaces of the first metal part and the second metal part, the first metal part with high hardness and the second part with high thermal conductivity and low specific gravity Metal parts are metal joined to achieve high heat dissipation, wear resistance and light weight characteristics.

In order to achieve the above object, the result of the process of the present invention is: at least one first metal part, the surface of the first metal part defines at least one first bonding surface and at least one first non-bonding surface, and is composed of at least one first An oxide layer covers the first bonding surface and the first non-bonding surface, and the specific gravity of the first metal part is 4.3 grams/cubic centimeter (g/cm ³ ) to 8 grams/cubic centimeter (g/cm ³ ), and the first metal part has a Rockwell Hardness (HRC) of 30 to 50, and has at least one second metal part, the surface of the second metal part defines at least one second bonding surface and at least one second non-bonding Surface, and the second bonding surface and the second non-bonding surface are covered by at least one second oxide layer, and the specific gravity of the second metal part is 1.68 g/cm ³ to 2.84 g/cm ³ Cm (g/cm ³ ), and the thermal conductivity of the second metal part is 130 watts ‧ meters/Kelvin (Wm/K) to 260 watts ‧ meters/Kelvin (Wm/K), and the The bonding area ratio of the first bonding surface and the second bonding surface is not less than 50%.

The steps to achieve the above result are: after the first metal part is subjected to the quenching process and the step of cooling to normal temperature, flux and welding medium are added at the first bonding surface and the second bonding surface, and the first bonding surface is The second bonding surfaces abut against each other, and then simultaneously heat the second metal part and the first metal part below the liquefaction critical temperature of the second metal part. This temperature is also used as the heating temperature of the tempering process of the first metal part to utilize heating The later flux removes and removes the first oxide layer on the surface of the first metal part and the second oxide layer on the surface of the second metal part, so that large holes are formed in the first oxide layer and the second oxide layer, and are exposed After the first bonding surface and the second bonding surface are reached, the welding medium enters the disengagement point and directly connects the first metal piece and the second metal piece, thereby completing a dense metal joint. In this way, a composite material with complementary characteristics of the first metal part and the second metal part is produced by metal bonding, and can simultaneously take into account the overall heat dissipation rate, light weight and wear resistance performance.

With the above technology, it is possible to solve the problems of poor thermal conductivity of aluminum alloy materials existing in conventional metal bonding, high cost of mechanical combination of aluminum and stainless steel, strict process conditions, too small contact area, and poor thermal conductivity. Make breakthroughs to achieve the practical progress of the above advantages.

1‧‧‧The first metal piece

11‧‧‧The first joint surface

111‧‧‧ First oxide layer

12‧‧‧The first non-joint surface

2‧‧‧Second metal parts

21‧‧‧Second joint surface

211‧‧‧Second oxide layer

22‧‧‧Second non-joint surface

3‧‧‧Flux

4‧‧‧Welding medium

Ta‧‧‧Time

Tb‧‧‧time

91‧‧‧First Metal

92‧‧‧Second metal

93‧‧‧ gap

94‧‧‧welding materials

95‧‧‧Oxide layer

The first figure is a schematic view of the conventional composite metal joint surface.

The second picture is a microscopic schematic view of the metal joint surface of the conventional composite material.

The third figure is a perspective view of a preferred embodiment of the present invention.

The fourth figure is a top view of a preferred embodiment of the present invention.

The fifth figure is a block flow diagram of a preferred embodiment of the present invention.

The sixth diagram is a schematic diagram of a heating time axis according to a preferred embodiment of the present invention.

The seventh figure is a schematic diagram (1) of the combined pre-operation according to the preferred embodiment of the present invention.

Figure 8 is a schematic diagram (2) of the combined pre-operation in the preferred embodiment of the present invention.

The ninth figure is a combined schematic diagram of a preferred embodiment of the present invention.

Fig. 10 is a schematic diagram of deoxidation bonding according to a preferred embodiment of the present invention.

Figure 11 is a schematic view of the bonding surface of the preferred embodiment of the present invention.

In order to achieve the above objectives and effects, the technical means and structure adopted by the present invention, the drawings and details of the preferred embodiments of the present invention are described in detail below. Their features and functions are as follows, so that they fully understand.

Please also refer to the third to eleventh figures, which are the perspective view to the joint surface schematic view of the preferred embodiment of the present invention. It can be clearly seen from the figure that the main steps of the present invention are: (a) take at least one A first metal part, the surface of the first metal part defines at least a first bonding surface and at least a first non-bonding surface, and the first bonding surface and the first non-bonding surface are covered by at least a first oxide layer , And the material specific gravity of the first metal part is 4.3 g/cm 3 (g/cm ³ ) to 8 g/cm 3 (g/cm ³ ), and the Rockwell hardness (HRC) of the first metal part is 30 To 50 (or Vickers hardness (HV) of 300 to 500); (b) after at least one first metal part is subjected to a quenching process and then cooled to room temperature; (c) at least one second metal part is used, and the second metal The surface of the component defines at least one second bonding surface and at least one second non-bonding surface, and the second bonding surface and the second non-bonding surface are covered by at least one second oxide layer, and the specific gravity of the second metal component It is 1.68 grams/cubic centimeter (g/cm ³ ) to 2.84 grams/cubic centimeter (g/cm ³ ), and the thermal conductivity of the second metal part is 130 watts ‧ meters/Kelvin (Wm/K) to 260 watts ‧ meters/Kelvin (Wm/K); (d) adding at least one flux and at least one welding medium to the junction of the first bonding surface and the second bonding surface; (e) adding the first The first bonding surface of the metal piece and the second bonding surface of the second metal piece abut each other; (f) heating the second metal piece to a predetermined temperature, the predetermined temperature being less than the liquefaction critical temperature of the second metal piece; (g) The predetermined temperature is simultaneously used as the heating temperature for the tempering process of the first metal part; (h) After the flux is heated, the first oxide layer on the first bonding surface and the second bonding surface are made The second oxide layer is detached and removed; (i) the welding medium connects the first metal part and the second metal part from the detachment of the first oxide layer and the second oxide layer; and (j) the first The bonding surface is metal-bonded with the second bonding surface, and the ratio of the bonding area between the first bonding surface and the second bonding surface is not less than 50%.

Through the above description, the structure of the present technology can be understood, and according to the corresponding cooperation of this structure, the first metal part with high hardness and the second metal part with high thermal conductivity and low specific gravity can be metal bonded, so that The overall metal characteristics are complementary, and achieve the advantages of high heat dissipation, wear resistance and light weight characteristics. The detailed explanation will be explained below.

The present invention utilizes a special process to perform metal bonding of two metals with different characteristics, such as brazing or non-melting (Welding) metal bonding, according to their respective high-quality characteristics. Complementary, in which the first metal part 1 is characterized by high hardness and wear resistance, but the thermal conductivity is low and the specific gravity is high, such as titanium or stainless steel (in this embodiment, stainless steel is taken as an example), and the second metal part 2 The system has the characteristics of low specific gravity and high thermal conductivity, but the hardness is low, such as magnesium or aluminum (in this example, aluminum is used as an example. In order to embody the process of metal bonding, a stainless steel sheet (first metal part 1 ) And aluminum disc brake discs (second metal 2) are implemented as joints.

In the present invention, when the first metal part 1 and the second metal part 2 are metal-joined, the purpose is to maximize the contact area between the two metals, and to effectively allow the heat accumulated in the first metal part 2 due to friction to be effectively passed through the The two metal parts 1 are scattered. When they are joined by brazing, the welding medium 5 directly connects the first metal part 1 and the second metal part 2 and has better structural strength, and no screws are needed. Locked, and because the hardened first metal part 1 can withstand higher strength friction, it is more safe and durable, and because the first metal part 1 mainly provides mechanical strength requirements, the proportion is relatively low, the main body is still It is the second metal part 2 with a low specific gravity, which can achieve the purpose of weight reduction.

At the time of production, as shown in the sixth figure, first of all, the first metal part 1 is subjected to a quenching process (steps a and b), and it is heated to 1000 to 1040 degrees (in this embodiment, 1020 degrees and time 0 to Ta are used as examples ), so that the first metal piece 1 is transformed from a softer pearlite solid phase to a harder Ma Tian scattered iron solid phase. During the transformation process, the atoms do not diffuse and the chemical composition does not change, but the lattice changes, and the new 1. The old solid phase maintains a certain positional relationship and has the characteristic of shear coherence. Therefore, after the quenching process of the first metal part 1, the Rockwell hardness can increase to HRC50~HRC58 according to its carbon content. Next, the first metal piece 1 of the Ma Tian scattered iron type is cooled to room temperature (step b, time Ta to Tb), the cooling method can be natural cooling, water cooling, etc., the choice of cooling rate will affect the surface hardness and the core Partial hardness, for example, during slow cooling due to eutectoid reaction, the phase changes into a wollastonite form. In addition, the tempering process of the first metal part 1 in the Martensite state during the joining can make the second metal part 2 and the first metal part 1 in the pearlite state while continuing to complete SUS420 And other series of stainless steel heat treatment.

After that, in order to perform the tempering process on the first metal part 1 again to heat it to a predetermined temperature (in this embodiment, it is 520 to 560 degrees, starting from time Tb), this tempering process can change the material properties of the metal, It reduces the quenching stress, stabilizes the shape and size of the stainless steel, and prevents the deformation or cracking of the quenched parts. At the same time, because the melting point of aluminum itself is about 660.4 degrees, it actually decreases the tensile strength at around 200 degrees (with temperature rising (The mechanical strength gradually decreases) and begins to soften (partial liquefaction) at about 565 degrees, so the predetermined temperature is also below the critical temperature of aluminum liquefaction, and the so-called critical temperature of aluminum below refers to the temperature before aluminum begins to liquefy. The three-phase diagram of aluminum is the upper limit of the absolute solid phase of aluminum (but aluminum is only (The examples of materials in the examples are not limited to this). Therefore, the heating operation of the second metal member 2 is also set to be heated to the predetermined temperature, and the second metal member 2 is indeed maintained in the solid phase state to avoid the phenomenon of semi-solid and semi-liquid, so as to utilize the subsequent bonding operation.

In addition, the biggest common point between aluminum and stainless steel is that the oxide layer on the surface belongs to a high-melting immobile oxide layer, and the oxidation of the oxide layer is almost instantaneously completed. The reason is that pure metal aluminum easily reacts with oxygen in the air to form A thin second oxide layer 211 covers the second bonding surface 21 and the second non-bonding surface 22 of the second metal part 2 exposed to the air. The second oxide layer 211 is an aluminum oxide film mainly preventing aluminum from Continue to oxidize; in the same way, the reason why metal stainless steel is not easy to rust is also because stainless steel contains 10% to 13% of chromium, and chromium is very easy to react with air to form a first oxide layer 111 (chromium oxide film), which is covered with On the first bonding surface 11 and the first non-bonding surface 12 of the first metal part 1 in the air. However, because the metal oxide is not a metal, it also becomes an obstacle to interconnection between metals, so that metal bonding cannot be achieved.

In order for the second metal part 2 and the first metal part 1 to be joined, the second oxide layer 211 on the second bonding surface 21 of the second metal part 2 and the first metal part 1 must be bonded together The first oxide layer 111 on the surface 11 is detached and removed. After the first metal part 1 is cooled to normal temperature, at least one flux 3 and at least one welding medium 4 are added to the junction of the first bonding surface 11 and the second bonding surface 21 (step d), and the first metal The first bonding surface 11 of the component 1 and the second bonding surface 21 of the second metal component 2 abut against each other (as shown in the seventh to ninth figures), so that without causing the second metal component 2 to break, The first bonding surface 11 of the first metal member 1 and the second bonding surface 21 of the second metal member 2 abut against each other (step e). At this time, under microscopic conditions, the physical properties of aluminum metal and stainless steel Due to the difference in characteristics, there is an irregular uneven surface between the first bonding surface 11 and the second bonding surface 21, and then, the first metal member 1 and the second metal member 2 are heated to the predetermined temperature at the same time (step f, g), the flux 3 acts on the first metal part 1 and the second metal part 2 to make the first oxide layer 111 on the first bonding surface 11 and the second oxide layer on the second bonding surface 21 211 Detach removal (step h). Wherein the flux 3 is ammonium chloride or a composite salt (ammonium chloride is used as an example in this embodiment, it can also be a composite salt composed of zinc chloride and potassium fluoride, or a mixture of at least two or more salts Compound salt), the aqueous solution of ammonium chloride is weakly acidic (composite salt is weakly alkaline), the acidity (or alkalinity) will be enhanced when heated, and may even become a gas with a smaller molecule, and due to the ammonium ion The ammonium chloride is corrosive to metals, and is more conducive to penetrating the fine pores of the second oxide layer 211 and the first oxide layer 111 to chemically react with the first metal part 1 and the second metal part 2 inside. Force the surfaces of the first metal piece 1 and the second metal piece 2 (the first A bonding surface 11 and a second bonding surface 12) collapse and dissociate, thereby causing larger holes in the fixed oxide layer (first oxide layer 111 and second oxide layer 211) contacting the surface. At the same time, in step (i), the welding medium 4 (such as aluminum-silicon alloy) is detached from the first oxide layer 111 and the second oxide layer 211 to directly connect the first metal part 1 and the second metal part 2 , So that the two solid metals are effectively metal bonded (as shown in the tenth figure).

Among them, the boiling point of ammonium chloride is about 520 degrees, and the second metal part 2 and the first metal part 1 at this time have been preheated to 520 ~ 560 degrees, so when ammonium chloride is added to the joint, the chlorine ammonium chloride is decomposed and reacts ammonia _{NH 4 Cl → NH 3 + HCl} , thereby generating chlorine ions (Cl ^-), and a second solid oxide layer 211 and the first oxide layer 111, there is actually a large number of small pores , while gaseous hydrogen chloride can easily pass through the plurality of holes, with aluminum and chromium metal directly under the action of; the second metal member 2 can thus react to form gaseous aluminum chloride Al ^{+ +} 3Cl directly with chloride ions ^- → AlCl3 and the first metal member 1 can be directly reacted with gaseous chlorine ion generation chromium chloride Cr ^{+ +} 3Cl ^- → CrCl3. In this way, by vaporizing the outermost layers of the second metal part 2 and the first metal part 1, the second oxide layer 211 and the first oxide layer 111 on the second metal part 2 and the first metal part 1 lose adhesion Remove from the base naturally.

Therefore, the second bonding surface 21 of the second metal member 2 and the first bonding surface 11 of the first metal member 1 can effectively perform metal bonding without the hindrance of the second oxide layer 211 and the first oxide layer 111 At this time, the first bonding surface 11 and the second bonding surface 21 can reach 50%≦lamination area<100% (as shown in the fourth and eleventh figures), and are made of metal bonding The aluminum-stainless steel composite material can greatly increase the path for the first metal member 1 to conduct heat to the second metal member 2 and effectively help the first metal member 1 dissipate heat. In this way, high heat dissipation and weight reduction are achieved, and at the same time, the effect of maximizing the contact area between the second metal member 2 and the first metal member 1 is used to increase the overall heat dissipation rate and wear resistance.

However, the above is only a preferred embodiment of the present invention, which does not limit the patent scope of the present invention, for example, it also includes aluminum-titanium composite materials, so it is easy to use the description and drawings of the present invention. Modifications and equivalent structural changes should be included in the patent scope of the present invention in the same way, and they should be combined with Chen Ming.

To sum up, when the metal bonding process of the present invention is used, in order to indeed achieve its efficacy and purpose, the present invention is an invention with excellent practicability. In order to meet the requirements for the application of the invention patent, you must file an application according to law. It is hoped that the review committee will grant the invention as soon as possible to protect the inventor's hard invention. If there is any doubt in the review committee of the Jun Bureau, please feel free to send us instructions and the inventor will try his best to cooperate.

1‧‧‧The first metal piece

11‧‧‧The first joint surface

111‧‧‧ First oxide layer

21‧‧‧Second joint surface

211‧‧‧Second oxide layer

4‧‧‧Welding medium

Claims (7)

A metal bonding process, the steps of which include: (a) taking at least one first metal part, the surface of the first metal part defines at least one first bonding surface and at least one first non-bonding surface, and is composed of at least one first The oxide layer covers the first bonding surface and the first non-bonding surface, and the specific gravity of the first metal part is 4.3 g/cm 3 (g/cm ³ ) to 8 g/cm 3 (g/cm ³ ) , And the Rockwell hardness (HRC) of the first metal part is 30 to 50; (b) After the quenching process of at least one first metal part, cooled to normal temperature; (c) Take at least one second metal part, the At least a second bonding surface and at least a second non-bonding surface are defined on the surface of the second metal part, and the second bonding surface and the second non-bonding surface are covered by at least a second oxide layer, and the second metal The specific gravity of the piece is 1.68 grams/cubic centimeter (g/cm ³ ) to 2.84 grams/cubic centimeter (g/cm ³ ), and the thermal conductivity of the second metal member is 130 watts·meter/degree Kelvin (Wm/ K) to 260 watts ‧ meter/Kelvin (Wm/K); (d) Add at least one flux and at least one welding medium to the junction of the first bonding surface and the second bonding surface; (e) The first bonding surface of the first metal piece and the second bonding surface of the second metal piece abut against each other; (f) heating the second metal piece to a predetermined temperature that is less than the liquefaction of the second metal piece Critical temperature; (g) The predetermined temperature is also used as the heating temperature for the tempering process of the first metal part; (h) After the flux is heated, the first oxide layer on the first bonding surface and the second The second oxide layer on the bonding surface is detached and removed; (i) the welding medium connects the first metal part and the second metal part from the detachment of the first oxide layer and the second oxide layer; and (j) The first bonding surface and the second bonding surface are metal-bonded, and the bonding area ratio of the first bonding surface and the second bonding surface is not less than 50%. The metal bonding process as described in item 1 of the patent application scope, wherein the operating temperature of the quenching process is 1000 degrees to 1040 degrees. The metal bonding process as described in item 1 of the patent application scope, wherein the flux is one of ammonium chloride or composite salt. According to the metal bonding process described in item 1 of the patent application scope, where the second metal part is aluminum, the predetermined temperature is 520 degrees to 560 degrees. The metal bonding process as described in item 4 of the patent application scope, wherein when the first metal part is stainless steel, the first oxide layer is chromium oxide, and the second oxide layer is aluminum oxide. The metal bonding process as described in item 1 of the patent application scope, wherein the metal bonding is one of brazing or non-melting (Welding) metal bonding. The metal bonding process as described in item 1 of the patent application scope, wherein the welding medium is an aluminum-silicon alloy.

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