JPS6221465A - Double layer padding method to aluminum base metal - Google Patents

Abstract

PURPOSE:To weld a different kind material to an Al base metal with a sufficient joining strength by padding a Cu self-fluxing alloy on the surface of the Al base metal, and padding the different kind material which is excellent in thermal resistance, resistance to wear, and corrosion resistance, on this alloy layer. CONSTITUTION:A Cu self-fluxing alloy powder 2 is applied onto an Al base metal 1, and thereafter, an Ar gas is fed from a side nozzle 6 and a laser beam 3 is irradiated, and a padding layer 4 of a Cu self-fluxing alloy is formed. Subsequently, an Ni super alloy powder which is excellent in thermal resistance, resistance to wear, and corrosion resistance is applied onto the padding layer 4, and thereafter, a padding layer of an Ni compound super alloy is formed in the same way. In this way, a desired different kind material can be welded onto the Al base metal with a sufficient joining strength.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a two-layer overlay method for overlaying dissimilar metal materials with excellent heat resistance, wear resistance, corrosion resistance, etc. onto an aluminum base material.

[Conventional technology]

Aluminum (Aβ) and aluminum alloys (hereinafter referred to as
(simply abbreviated as aluminum) has a specific gravity of approximately 1/3 that of iron.
Because of its light weight, it is used in various fields as a substitute for iron. In particular, it is often used in fields where weight is directly linked to performance, such as aircraft and vehicles.

By the way, although aluminum is lightweight, it is not necessarily sufficient for use in parts that require heat resistance, wear resistance, corrosion resistance, etc., such as sliding parts of automobiles.
It may not be possible to use it as is. Therefore, in order to make use of aluminum's light weight properties while providing additional properties such as heat resistance, abrasion resistance, and corrosion resistance, it may be possible to bond dissimilar materials with these properties to the surface of aluminum. This joining method includes mechanical methods and brazing, but the joining strength with the aluminum base material is not necessarily sufficient.

In order to increase this bonding strength, it is desirable to metallurgically bond aluminum and a dissimilar material having the above characteristics.

[Problem that the invention seeks to solve]

By the way, when attempting to join dissimilar materials with excellent heat resistance, wear resistance, and corrosion resistance to the surface of an aluminum base material by overlay, which can be expected to form a metallurgical bond, the dissimilar materials may become Ni-based superalloys or CO-based superalloys. In the case of metals such as alloys, since the melting point of these build-up alloys is high, the aluminum-based base material melts and forms an alloyed layer with aluminum, making it impossible to form a build-up layer. For this reason, not only the necessary properties such as heat resistance, wear resistance, and corrosion resistance cannot be obtained, but also aluminum, iron (Fe), cobalt (CO), nickel (Ni)
Hard and brittle intermetallic compounds are formed between alloying elements such as chromium (Cr), molybdenum (MO), and tungsten (W), resulting in insufficient bonding strength with the aluminum base material and cracking. There is a problem that overlay cannot be done due to the occurrence of such problems.

Therefore, it has been desired to develop a build-up method for firmly joining dissimilar metal materials with excellent heat resistance, wear resistance, corrosion resistance, etc. to an aluminum base material.

[Means for Solving the Problems] The above problems are solved by the following two-layer overlay method on an aluminum base material of the present invention.

That is, the two-layer overlay method of the present invention is a two-layer overlay method for overlaying an overlay material with excellent heat resistance, wear resistance, etc. on an aluminum base material. It is characterized by overlaying a copper-based self-fusing alloy on the surface, and overlaying an overlay alloy with excellent heat resistance, wear resistance, and corrosion resistance on the copper-based self-fluxing alloy.

In the present invention, a copper-based self-fluxing alloy is used as an intermediate material that connects the aluminum-based base material and the overlay alloy. This copper-based self-fusing alloy is based on copper, and this copper contains boron (
B), and at least one of silicon (St) is added. Usually both are added. Both boron and silicon are self-soluble elements, and are added to improve wettability. It is desirable that the amount of boron added is 0.1 to 5.0% by weight (hereinafter all % indicates weight %), and the amount of silicon added is 0.5 to 5.0%. Here, the amount of boron added is 0.
The reason why it is set at 1 to 5.0% is because if it is less than 0.1%, the effect of improving wettability is not sufficient, and if it exceeds 5.0%, it becomes brittle and tends to form cavities. It is. In addition, the amount of silicon added was set at 0.5 to 5.0% because if it is less than 0.5%, the effect of improving wettability is insufficient, and if it exceeds 5.0%, it is dangerous. Because it will be.

Further, when both boron and silicon are added, it is desirable that the total amount of boron and silicon is 1% or more and 8% or less. This is because if (B+Si) is less than 1%, copper cannot wet the aluminum surface and the bonding strength becomes weak; if it is more than 8%, cracks and surface roughness become severe and overlay cannot be applied. It is from.

The basic component of the copper-based self-fluxing alloy in the present invention is a copper base with boron and silicon added, but since the specific gravity of boron is small, when boron is added, it can be mixed with other components. It is usually added in the form of boride. At this time, the elements that form boron and boride include nickel,
There are iron, chromium, cobalt, etc. Therefore, these components are inevitably added to the copper-based self-fluxing alloy of the present invention.

On this copper-based self-fluxing alloy, dissimilar metal materials with excellent heat resistance, wear resistance, and corrosion resistance are metallurgically joined by overlay. Note that as metals having excellent heat resistance, wear resistance, and corrosion resistance, for example, cobalt-based superalloys, nickel-based superalloys, iron-based superalloys, etc. can be used. This cobalt-based superalloy is a well-known alloy developed based on stellite.
It mainly relies on solid solution strengthening by adding molybdenum (Mo) and tungsten (W) and dispersion strengthening of chromium (Cr) carbide. Examples of cobalt-based superalloys include +
al weight% (hereinafter, all units are weight%), C1.5%, Si: 1.1%, Ni: 1.5%, Cr
: 30.0%, Mo: 0.6%, W: 4-12.0%,
Fe < 1.5% and balance Co, (blCl, 2
5%, Si: 1.1%, Ni: 22.0%, Cr: 26
．． 0%, B: 0.2%, Fe<1.5% and balance Co
etc. can be used.

In addition, nickel-based superalloys contain around 20% chromium (Cr).
In addition, aluminum (Aβ) is added in terms of high-temperature strength.
It is a precipitation-strengthened alloy to which titanium (Ti) and niobium (Nb) are added. Examples of nickel-based superalloys include +
al weight% (hereinafter all units are weight%), Co < 1.5%, Cr: 14-23%, MO: 5
~16%, W<4.0%, Fe<5.0%, St
<0.8%, Mn<1.0%, C: 0.05-0.1%
, Ca: 0.1-2.0% and the balance N i , (b
lCo<5.0%, Cr:18-22%, MO
83-6%, Fe < 4.0%, St < 1.0%,
Mn<1.0%, c: o, os ~ o, i%, Ca: 0
, 1-2.0%, A # < 1.0% and balance Ni
etc. can be used.

In addition, iron-based superalloys are improved Ni-Cr steels, and are alloys with improved corrosion resistance with Cr, reduced Fe content and increased Ni content to prevent embrittlement caused by Cr, and MOLW for strength. , An! , a solid solution strengthening element such as Ti, and a precipitation strengthening element are added. Examples of this iron-based superalloy include M-813 and Incoly 9.
01 etc. can be used.

In the present invention, a high-density energy source such as a laser or TlG1 plasma can be used as a heat source when overlaying a copper-based self-fluxing alloy or overlaying alloy.

[Effect]

The copper-based self-fluxing alloy used in the present invention has a melting point between that of aluminum and a different material with excellent heat resistance, wear resistance, and corrosion resistance, and this melting point is 30° higher than that of aluminum.
Since the difference is only about 0°C, there is no possibility of melting the aluminum base material as in the past.

Further, since boron and silicon contained in the copper-based self-fluxing alloy are self-fusing, they have good wettability with the aluminum-based base material and a different material with excellent heat resistance, wear resistance, and corrosion resistance. Therefore, the bonding strength is also high.

In addition, the copper-based self-fusing alloy of the present invention is based on copper, and the intermetallic compound of copper and aluminum that is formed in the alloyed layer formed when joining the aluminum base material and the intermediate overlay material contains other elements. Unlike other cases, it is hard and has toughness.

Furthermore, the Vickers hardness of the copper-based self-fusing alloy is Hv: 100.
Because it is soft and sticky (~200%), even if the material to be overlaid on a copper-based self-fluxing alloy is hard, it can be overlaid without causing cracks or the like.

Therefore, according to the present invention, a dissimilar metal material having excellent heat resistance, wear resistance, and corrosion resistance can be overlaid on an aluminum base material while maintaining sufficient bonding strength.

〔Example〕

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

(First Example) As a first example, an example will be shown in which a nickel-based superalloy is overlaid on an aluminum-based base material via a copper-based self-fluxing alloy.

Here, FIG. 1 is a schematic configuration diagram showing each step of a two-layer overlay method on an aluminum base material according to a first embodiment of the present invention,
FIG. 2 is a photograph (x'io>) showing the metal structure of the built-up layer obtained in the first example of the present invention.

A rectangular test piece 1 of 30 m x 60 n x 10 m made of an aluminum base material (JIS ADCIO) was prepared, and a Ni-based superalloy was overlaid thereon. First, on this test piece 1, a copper-based self-fusing alloy powder 2 consisting of 1%B-2%5T-10%Ni-10%Cu was added using a 3% polyvinyl alcohol aqueous solution to a thickness of 1mm and a width of 511mm long. It was applied to a thickness of 50 wm and dried at 100° C. for 20 minutes. next,
The copper-based self-fluxing alloy powder 2 was welded using a laser beam 3 as a heat source to obtain a first overlay layer 4. At this time, argon gas 7 was supplied to the molten pool 5 as a shielding gas from a side nozzle 6 at a rate of IOJ/min to prevent oxidation. In addition, the laser deposition conditions are power density: 200W.
/in'', energy density: 90 J/w'', scanning speed near, 5 g/sec. FIG. 1 ta+ shows the state in the middle of laser build-up at this time.

Next, on top of this first overlay layer 4, a 25% dissimilar metal material with excellent heat resistance, wear resistance, and corrosion resistance is applied using a laser beam as a heat source in the same manner as in the case of copper-based self-fluxing alloys. Cr
A Ni-based superalloy consisting of -1.5%+3-1%5t-8%Mo-balance Ni was overlaid. That is, as in the case of the first build-up layer 4, the Ni-based super-superalloy powder is placed on the first build-up layer 4 to a thickness of 1.5 mm, a width of 4.5 mm, and a length of 50 mm. After applying the film in small areas and drying it thoroughly, a laser beam 3 was irradiated while supplying a shield gas 4 and an argon gas 7 at a rate of 1047 parts. At this time, the laser deposition conditions were: power density: 300 W/1m", energy density:
120 J/111", scanning speed near, and 5 NWA/sec. The state during the laser build-up at this time is shown in Figure 1 (bl). As a result, the first build-up layer 4 A second build-up layer 9 made of a Ni-based superalloy welded to the first build-up layer 4 was formed thereon.

The metal structure of the cross section of the built-up part at this time is shown in the photograph (X
IO). As can be seen from Figure 2, there is some dilution in the welded areas between the aluminum base material and the first build-up layer, and between the first build-up layer and the second build-up layer, but the other parts are Two build-up layers were obtained in almost perfect form with no dilution and no cracks. This is because the copper-based self-fluxing alloy, which is the intermediate overlay material, has good wettability with both the aluminum-based base material and the Ni-based superalloy, and the melting point of the aluminum-based base material is 538°C to 593°C, and the Ni-based While the melting point of the superalloy is 1240°C to 1303°C, the melting point of the copper-based self-fluxing alloy of this example is approximately between 940°C and 10°C.
This is interpreted to be because it is 30”C.

(Second Example) As a second example, an example will be shown in which a cobalt-based superalloy is overlaid on an aluminum-based base material via a copper-based self-fluxing alloy.

FIG. 3 is a photograph (XIO) showing the metal structure of the built-up layer obtained in the second example of the present invention.

The second embodiment differs from the first embodiment in that JIS AC4C was used as the aluminum base material;
28%Cr-1%C-4%W as the material for the second overlay layer
- Due to the use of a Co-based superalloy with the remainder being Co and the difference in the second build-up material, the laser build-up conditions for forming the second build-up layer were: power density: 350 W/Tsuru 2;
Two-layer overlay was carried out in substantially the same manner as in Example 1 except that the energy density was 150 J/**'' and the scanning speed was 5 m/sec.

The metal structure of the cross section of the built-up part at this time is shown in the photograph (X
10). As can be seen from Figure 3, some dilution is seen in the welded areas between the aluminum base material and the first overlay layer, and between the first overlay layer and the second overlay layer, but the other parts are Two build-up layers were obtained in almost perfect form without any dilution or cracking. This is because the copper-based self-fluxing alloy, which is the intermediate overlay material, has good wettability with both the aluminum-based base material and the Co-based superalloy, and the melting point of the aluminum-based base material is 550°C to 610°C. The melting point of the alloy is 1,260°C to 1,357°C, whereas the melting point of the copper-based self-fluxing alloy of this example is approximately in the middle, 940°C to 1,357°C.
This is understood to be because the temperature is 0.030°C.

(Third Example) As a third example, an example will be shown in which an iron-based superalloy is overlaid on an aluminum-based base material via a copper-based self-fluxing alloy.

FIG. 4 shows the metal &
This is a photograph (XIO) showing FI weave.

The third embodiment differs from the first embodiment in that a copper-based self-fluxing alloy consisting of 3% B-15% Ni and the balance Cu is used as the material for the first build-up layer, and that the second build-up layer 1%B-3%5i-10%Ni-20%Cr-
The use of an Fe-based superalloy consisting of Fe as the remainder, and the use of TIG instead of a laser to form the second overlay layer, and the TIG (7) processing conditions were as follows: Current: 12OA
, Voltage: 2°V, otherwise two-layer overlay was carried out in substantially the same manner as in the first example.

The metal structure of the cross section of the built-up part at this time is shown in the photograph (x
1O). As can be seen from Figure 4, some dilution is seen in the welded areas between the aluminum base material and the first overlay layer, and between the first overlay layer and the second overlay layer, but other parts are Two build-up layers were obtained in almost perfect form with no dilution and no cracks. This is because the copper-based self-fluxing alloy, which is the intermediate overlay material, has good wettability with both the aluminum-based base material and the Fe-based superalloy, and the melting point of the aluminum-based base material is 538°C to 593°C, and the Fe-based While the melting point of the superalloy is 1350°C to 1420°C, the melting point of the copper-based self-fluxing alloy of this example is approximately in the middle, 980°C to 10°C.
This is understood to be because the temperature is 60°C.

(Fourth Example) As a fourth example, the stress relaxation effect during build-up of a copper-based self-fluxing alloy was investigated.

Here, FIG. 5 is a graph showing the number of repetitions until cracking occurs in the two-layer overlay members obtained in the fourth example of the present invention and the comparative example.

The fourth embodiment differs from the first embodiment in that the base material is a steel plate (JIS
545C) was used, and 1% was used as the intermediate overlay material.
B-2% 5t-10% Ni-balance Cu, using a copper-based self-fluxing alloy, 30% as the material of the second overlay layer
The reason is that a Ni-based superalloy consisting of Cr-5%W-2゜5%C-4%St-the balance Ni is used, and the rest is substantially the same as the first one.
Three test pieces were prepared using two-layer overlay in the same manner as in the example.

Similarly, as a comparative example, three test pieces were prepared in which the Ni-based superalloy was directly overlaid onto a base steel plate without using the copper-based self-fluxing alloy as the intermediate overlay material.

The six test pieces obtained were placed in a constant temperature bath at 600°C.
The number of repetitions until cracking occurred in the overlaid Ni-based superalloy was investigated, with one cycle consisting of alternately placing the samples in a bath at 0°C.

The results are shown in FIG. As is clear from Figure 5,
It can be seen that the thermal fatigue properties of the test pieces a''-c of this example are approximately twice as high as those of the conventional test pieces d-f that do not use an intermediate overlay material.

Although specific embodiments of the present invention have been described above, the present invention is not limited to the above embodiments, but includes various embodiments within the scope of the claims.

〔Effect of the invention〕

As described above, according to the method of two-layer overlaying on an aluminum base material of the present invention, the following effects are achieved.

(a) Different materials with excellent heat resistance, wear resistance, and corrosion resistance can be welded to an aluminum base material with sufficient bonding strength. Therefore, it is possible to obtain a component that has both the light weight of aluminum and the heat resistance, wear resistance, corrosion resistance, etc. of a different material.

(b) Copper-based self-fluxing alloys are soft and sticky, so even if the overlay material is hard, cracks do not occur because the stress during overlay is relaxed. Furthermore, the thermal fatigue properties of the overlay material after overlaying are improved.

[Brief explanation of the drawing]

Fig. 1 is a schematic configuration diagram showing each step of a two-layer overlay method on an aluminum base material according to the first embodiment of the present invention, and Fig. 2 is a schematic diagram showing the overlaying method obtained in the first embodiment of the present invention. A photograph (XIO) showing the metallographic structure of the layer, Fig. 3 shows the metal m of the built-up layer obtained in the second example of the present invention.
Figure 4 is a photograph (x10) showing the metal structure of the overlay layer obtained in the third example of the present invention, Figure 5 is a comparison with the fourth example of the present invention. Obtained in example 1. It is a graph showing the number of repetitions until cracking occurs in a two-layer overlay member. 1-...-Aluminum base material 2--Copper-based self-fluxing alloy 3--Laser beam 4--First overlay layer 5--1 Molten pool 6・---1−・−・Side nozzle 7−・−・−Argon gas (shielding gas) 8−・・・・
---Ni-based superalloy powder 9--Second overlay layer applicant Toyota Motor Corporation Figure 2 Figure 3 (x10) Figure 4 (xlo) Figure 5 Ministry and filler layer 1 Arrogant phrase 1

Claims (1)

[Claims] (1) A two-layer overlay method for overlaying an overlay material with excellent heat resistance, wear resistance, etc. on an aluminum base material, in which a copper-based self-fusing alloy is overlaid on the surface of the aluminum base material. Serve,
A two-layer overlay method for an aluminum base material, characterized by overlaying a overlay alloy with excellent heat resistance, wear resistance, and corrosion resistance on this copper-based self-fluxing alloy.