JP2003275882A - Clad material and laser cladding method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To easily form a clad layer having uniform welding force on the whole of a boundary face with a base material. <P>SOLUTION: A clad material 1 is fused along the continuous part to be clad on an aluminum rolled flat plate 5 by thermal irradiation. In the cross- sections crossing the clad material 1 located on the aluminum rolled flat plate 5, the height to the aluminum rolled flat plate 5 in the center part 2 in the width direction is made lower than that of both side parts 3 in the width direction, so that a satisfactory welding condition can be obtained not only in both side parts 3 in the width direction, but also in the central part 2 in the width direction. <P>COPYRIGHT: (C)2003,JPO

Description

Detailed Description of the Invention

[0001]

TECHNICAL FIELD The present invention relates to a clad material suitable for forming a clad layer in a laser clad process for forming a clad layer as a wear resistant layer on a base material by irradiating a laser beam. The present invention relates to a laser cladding method using this.

[0002]

Since the wire-shaped clad material used in the above-mentioned laser clad processing has a circular or rectangular cross-sectional shape, when performing laser clad processing, the base material is When laser light is irradiated to the clad material placed on the clad material, melting gradually starts from the laser-irradiated surface of the clad material and melts down from both sides in the width direction. In the central portion, the amount of heat input is relatively insufficient and it becomes difficult to melt, and as a result, there is a possibility that a non-uniform melting state occurs.

That is, even if a good welded state is obtained at both sides of the clad material in the width direction, there is a possibility that welding defects may occur at the center portion in the width direction at the boundary surface with the base material (see FIG. 6). ), In order to avoid this, if the heat input to this part is sufficiently large, the base material melts into the clad material on both sides in the width direction, which causes excessive heat input, resulting in dilution of the clad material, resulting in welding. Defects such as insufficient strength and cracks may occur, and the clad layer having these defects will be rejected in the inspection process. Therefore, conventionally, there is a problem that it cannot be said that it is easy to form a clad layer having a uniform welding force over the entire boundary surface with the base material. Had been a problem.

[0004]

SUMMARY OF THE INVENTION The present invention has been made in view of the above-mentioned conventional problems, and it is possible to easily form a clad layer having a uniform welding force over the entire boundary surface with the base material. The present invention aims to provide a material and a laser cladding method.

[0005]

According to a first aspect of the present invention, in a clad material which is irradiated with heat and melted along a continuous cladding portion on the base material, the clad material is located on the base material. It is characterized in that the thickness of the central portion in the width direction of the cross section of the clad material is set to be thinner than the thickness of both side portions in the width direction. It is a means to solve it.

The clad material according to claim 2 of the present invention is
In the cross section across the clad material located on the base material,
The height of the central portion in the width direction with respect to the base material is lower than the height of both side portions in the width direction.

The clad material according to claim 3 of the present invention is
The cross section of the clad material located on the base material has a concave shape.

According to a fourth aspect of the present invention, in the laser cladding method, the clad material according to the first to third aspects of the present invention is cast-molded, press-molded or fired according to the shape of the continuous cladding portion on the base material. The clad material is formed by binding, and the clad material is irradiated with laser light in a state where the clad material is directly placed on the cladding portion on the base material.

[0009]

In the clad material according to the first aspect of the present invention, when the laser clad processing is carried out, when the laser beam is radiated on the base material, melting is gradually started from the laser-irradiated surface of the clad material. Since it melts almost uniformly in the width direction of the cross section that crosses the continuous clad material, a good welded state can be obtained not only at both widthwise side portions at the boundary surface with the base material but also at the widthwise central portion. Therefore, it is not necessary to increase the amount of heat input in order to avoid defective welding in the center portion in the width direction, and it is possible to avoid the occurrence of defects such as cracks due to excessive heat input on both side portions in the width direction.

In the clad material according to claims 2 and 3 of the present invention, when the laser clad processing is performed, when laser light is radiated on the base material, melting is gradually started from the laser-irradiated surface of the clad material. In the cross section that crosses the continuous clad material, the height of the central portion in the width direction with respect to the base material is lower than the height of both side portions in the width direction (the clad material of claim 3 has a concave cross section). Therefore, the amount of heat input required for melting is obtained not only at both sides in the width direction at the boundary surface with the base metal but also at the center in the width direction, resulting in a substantially uniform molten state, resulting in problems such as insufficient welding force and cracks. Instead, a clad layer having a uniform welding force is formed on the entire boundary surface with the base material.

In the laser cladding method according to the fourth aspect of the present invention, the laser beam is applied in a state where the clad material formed according to the shape of the continuous cladding portion on the base material is directly placed on the base material. Since the irradiation is performed, the system can be simplified and the control of the supply of the clad material is unnecessary because the clad material supply device that can control the supply timing and the supply amount of the clad material is unnecessary. In addition to this, there is no need to synchronize the laser light irradiation timing with the supply of the clad material, and only the laser output needs to be controlled during the clad processing, so that the factors that cause quality variations are greatly reduced. .

[0012]

Since the clad material according to claim 1 of the present invention has the above-mentioned structure, when performing the laser clad processing, not only the widthwise both sides of the boundary surface with the base material but also the widthwise central portion. However, it is possible to obtain a good welding state, and therefore it is possible to form a clad layer having a uniform welding force over the entire boundary surface with the base material without problems such as insufficient welding force and cracks. Has an excellent effect on.

Since the clad material according to the second and third aspects of the present invention has the above-mentioned structure, when the laser clad processing is performed, when the laser beam is radiated on the base material, the boundary surface with the base material is irradiated. As a result, the molten state is almost uniform as a whole. Therefore, it is possible to form a clad layer having a uniform welding force over the entire interface with the base material without causing defects such as insufficient welding force and cracks. That is a very good effect.

Since the laser cladding method according to claim 4 of the present invention has the above-mentioned configuration, the system can be simplified and the quality can be improved. Excellent effect is brought about.

[0015]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described below with reference to the drawings.

1 to 3 show an embodiment of the clad material according to the present invention.

As shown in FIG. 1, the clad material 1 is
A rod-shaped member made of a copper alloy (Cu-14Ni-3Si-1.5Fe-2Cr-1Al-2V-0.5P), which has a widthwise central portion 2 and widthwise opposite side portions 3 in a cross section of the clad material 1. The heights from the respective boundary surfaces 4 are different from each other so that the widthwise both side portions 3 are higher than the widthwise central portion 2, that is, the cross-sectional shape is concave.

In this case, the height from the boundary surface 4 of the central portion 2 in the width direction is set to 2a, while the height from the boundary surface 4 of both side portions 3 in the width direction is set to 3a, and the height of the central portion 2 in the width direction is set to 3a. The width is set to 2a, which is half the total width 4a.

Therefore, as shown in FIG. 2, the clad material 1 is placed and fixed on an aluminum rolled flat plate 5 as a base material, and the clad material 1 is output from a heat source direct diode laser (not shown) 2. 1 irradiated with 5kW
A laser beam L having a rectangular beam spot with a side of 1.9 mm is applied, and the processing speed is 0.4 to 1.6 m / min. Then, scanning was performed in the direction of the arrow shown. At this time, for comparison, laser clad processing was performed on the clad material (10) having a substantially square cross section under the same conditions as above.

The sectional shape of the cladding layer C (C10) obtained by this laser cladding processing is shown in FIGS. In these FIGS. 3 and 6, the cross-sectional shapes of the clad materials 1 and (10) before melting are all shown by imaginary lines.

As shown in FIG. 3, in the clad material 1 according to this embodiment, a boundary surface 4 with an aluminum rolled flat plate 5 is used.
The good welded state is obtained not only on the both side portions 3 in the width direction but also in the center portion 2 in the width direction. On the other hand, as shown in FIG. Although a good welded state was obtained on both side portions 13 in the width direction, a weld defect was generated at the widthwise central portion 12 at the boundary surface 14 with the aluminum rolled flat plate 5, and therefore the clad according to this embodiment was used. Material 1
According to the above, it was demonstrated that the cladding layer C having a uniform welding force over the entire interface 4 can be easily formed without causing problems such as insufficient welding force and cracks.

In the above-mentioned embodiment, the height from the boundary surface 4 of each of the widthwise central portion 2 and the widthwise both side portions 3 in the cross section which crosses the continuous clad material 1 is different from each other so that the cross sectional shape is concave. However, the cross-sectional shape of the clad material should be such that the thickness of the central portion 2 in the width direction is thinner than the thickness of both side portions 3 in the width direction so that the clad material can be melted uniformly in the width direction of the cross section. Often, for example, as in the clad material 1A shown in FIG. 4A, the indentation of the width direction central portion 2A located between the width direction both side portions 3A is formed in a triangular shape.
Like the clad material 1B shown in (b), both side portions 3 in the width direction
It is possible to make the indentation of the widthwise central portion 2B located between B in an arc shape. Further, the widthwise central portions 2, 2A, 2B in the cross section that crosses the continuous clad material 1
Does not have to be in contact with the boundary surface 4, and as in the clad material 1C shown in FIG. 4 (c), a joint portion between the circular width direction side portions 3C, 3C, that is, from the boundary surface 4 It is also possible to make the joining portion between the width direction side portions 3C, 3C located at distant portions the width direction central portion 2C.

FIG. 5 shows a laser cladding method using a clad material according to the present invention. In this embodiment, the laser cladding method according to the present invention is adopted for laser clad processing for a valve seat of an engine. Indicate the case.

As shown in FIG. 5, the clad material 21 of this embodiment has a ring fitting portion (clad portion) formed by boring on a valve seat (base material) 25.
It is formed into a ring shape by casting, press molding, or sintering according to the shape of 26, and has the same cross-sectional shape as the clad material 1 in the above-mentioned embodiment. The clad material 21 molded in the above is fitted into the ring fitting portion 26 of the valve seat 25, and the laser light L is irradiated.

In this laser cladding method, a clad material supply device capable of controlling the supply timing and the supply amount of the clad material 21 is not required, and the system can be simplified correspondingly and the supply control of the clad material 21 can be achieved. In addition to the above, it is not necessary to synchronize the irradiation timing of the laser light L with the supply of the clad material 21, and it is sufficient to control only the laser output during the clad processing. As a result, there is a variation in quality. The factors that occur will be greatly reduced.

[Brief description of drawings]

FIG. 1 is a cross-sectional explanatory view showing an example of a clad material according to the present invention.

FIG. 2 is a perspective explanatory view showing a situation where laser clad processing is performed using the clad material in FIG.

3 is a cross-sectional explanatory diagram of a clad layer obtained by laser clad processing using the clad material in FIG.

FIG. 4 is sectional explanatory views (a), (b) and (c) showing another embodiment of the clad material according to the present invention.

FIG. 5 is a perspective explanatory view showing a situation in which laser clad processing is performed by a laser cladding method according to an embodiment of the present invention.

FIG. 6 is a cross-sectional explanatory diagram of a clad layer obtained by laser clad processing using a clad material of a comparative example.

[Explanation of symbols]

1,1A, 1B, 1C, 21 Clad material 2,2A, 2B, 2C width direction central part 3,3A, 3B, 3C Width side 4 boundaries 5,25 Aluminum rolled flat plate (base material) 26 Ring fitting part (cladding part) L laser light

Claims (4)

[Claims] 1. A clad material which is irradiated with heat and melted along a continuous cladding portion on a base material,
A clad material, characterized in that the thickness of the central portion in the width direction of the cross section of the clad material located on the base material is smaller than the thickness of both side portions in the width direction. 2. The clad material according to claim 1, wherein a height of a central portion in the width direction with respect to the base material is lower than heights of both side portions in the width direction in a cross section of the clad material located on the base material. . 3. The clad material according to claim 1, wherein a cross section of the clad material located on the base material has a concave shape. 4. The clad material according to any one of claims 1 to 3 is formed according to the shape of the continuous cladding portion on the base material, and the cladding material is placed directly on the cladding portion on the base material. A laser cladding method comprising irradiating a laser beam to a clad material in a closed state.