Manufacturing method of the build-up layer

Abstract

To provide a method for manufacturing a build-up layer, which can suitably apply a laser beam to a metal powder layer.SOLUTION: The method for manufacturing the build-up layer supplies metal powder to a workpiece W10 to form a metal powder layer containing the metal powder, and applies a laser beam to the metal powder layer to form a build-up layer in the workpiece W10. The method for manufacturing the build-up layer comprises: a step ST2 of measuring a shape of the metal powder layer from the time of starting supplying of the metal powder to the elapse of prescribed time; and a step ST3 of setting a laser application range in accordance with the shape of the metal powder layer.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present disclosure relates to a method for manufacturing a build-up layer. [Background technology]

[0002] In the method for manufacturing a buildup layer disclosed in Patent Document 1, a copper-based metal powder is supplied to the surface of a substrate while being irradiated with a laser beam to melt the metal powder. While the metal powder is being supplied and melted, the supply position of the metal powder and the irradiation position of the laser beam are moved in a predetermined direction along the surface of the substrate. Furthermore, a buildup layer is formed along the predetermined direction on the surface of the substrate. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Publication No. 2018-158347 Summary of the Invention [Problem to be solved by the invention]

[0004] The inventors of the present application have discovered the following problems. In this type of build-up layer manufacturing method, the supply device that supplies the metal powder is positioned a certain distance from the processing point to ensure uniformity in the supply amount. Therefore, the supply amount of metal powder does not immediately become constant, and the shape of the metal powder layer made of the supplied metal powder may change significantly. As a result, there is a risk that the laser may not be able to properly irradiate the metal powder layer.

[0005] The present disclosure has been made in consideration of the above-mentioned problems, and provides a method for manufacturing a buildup layer that can appropriately irradiate a laser onto a metal powder layer. [Means for solving the problem]

[0006] The method for manufacturing a buildup layer according to the present disclosure is a method for manufacturing a buildup layer in which a metal powder layer made of the metal powder is formed by supplying the metal powder to a workpiece, and a laser is irradiated onto the metal powder layer to form a buildup layer on the workpiece, and includes the steps of measuring the shape of the metal powder layer from the time when the supply of the metal powder begins until a predetermined period of time has elapsed, and setting the irradiation range of the laser to a range corresponding to the shape of the metal powder layer.

[0007] Furthermore, in the above-mentioned method for manufacturing a buildup layer, in the step of measuring the shape of the metal powder layer, the point at which the specified period has elapsed may be the point at which the supply amount of the metal powder has reached a target value.

[0008] In addition, the above-mentioned method for manufacturing a buildup layer may further include a step of resetting the laser irradiation range to a range larger than the range corresponding to the shape of the metal powder layer after the supply amount of the metal powder has reached a target value.

[0009] Further, in the method for manufacturing the buildup layer described above, after the supply amount of the metal powder has reached a target value, a step of measuring the shape of the metal powder layer again; The method may further comprise the step of resetting the laser irradiation range to a range according to the shape of the metal powder layer measured again. [Effects of the Invention]

[0010] According to the present disclosure, the laser can be appropriately irradiated onto the metal powder layer. [Brief explanation of the drawings]

[0011] [Figure 1] 4 is a flowchart showing an example of a method for manufacturing a build-up layer according to the first embodiment. [Figure 2] 4 is a diagram showing an area where a buildup layer is formed in an example of a method for manufacturing a buildup layer according to the first embodiment. FIG. [Figure 3]3 is a schematic cross-sectional view showing a laser irradiated portion at the start of laser irradiation in an example of a welding method according to the first embodiment. FIG. [Figure 4] 4 is a graph showing the flow rate of metal powder with respect to time in an example of a welding method according to the first embodiment. [Figure 5A] 3 is a schematic diagram showing a laser irradiation range on a laser irradiated surface at the start of laser irradiation in an example of a welding method according to the first embodiment. FIG. [Figure 5B] 4 is a schematic diagram showing a laser irradiation range on a laser-irradiated surface after a predetermined time has elapsed since the start of laser irradiation in an example of a welding method according to the first embodiment. FIG. [Figure 6] 4 is a schematic cross-sectional view showing a laser irradiated portion after a predetermined time has elapsed since the start of laser irradiation in an example of a welding method according to the first embodiment. FIG. DETAILED DESCRIPTION OF THE INVENTION

[0012] Hereinafter, specific embodiments to which the present invention is applied will be described in detail with reference to the drawings. However, the present invention is not limited to the following embodiments. In addition, the following description and drawings have been simplified as appropriate for clarity of explanation.

[0013] <First Embodiment> The first embodiment will be described with reference to Figures 1 to 6. Figure 1 is a flowchart showing an example of a method for manufacturing a build-up layer according to the first embodiment.

[0014] Naturally, the right-handed XYZ coordinate system shown in Figure 2 and other drawings is for the convenience of explaining the positional relationships of the components. Normally, the positive Z axis is vertically upward, and the XY plane is the horizontal plane, which is common among the drawings.

[0015] In one example of the method for manufacturing a buildup layer according to the first embodiment, for example, a laser clad processing apparatus can be used. The laser clad processing apparatus includes, for example, a holding device, a laser processing head, a rotation device, a supply device, and a control device. The holding device tilts and holds the workpiece. The laser processing head ejects metal powder while irradiating a processing point on the workpiece surface with a laser beam. The rotation device holds the laser processing head at an inclination in the vertical direction and rotates it about a vertical axis, thereby moving the supply position of the metal powder from the laser processing head and the irradiation position of the laser beam at the processing point in the circumferential direction. For example, the supply device uses the pressure of the carrier gas to send the metal powder together with the carrier gas and supply the metal powder to the laser processing head. The control device controls the supply state of the metal powder from the supply device to the laser processing head and the laser output of the laser processing head. The control device may execute a processing program and perform numerical control. The control device may also acquire information measuring the shape of the metal powder layer and control the laser irradiation range based on the acquired information.

[0016] In one example of the method for manufacturing a cladding layer according to the first embodiment, first, supplying metal powder to the workpiece begins (step ST1). The metal powder is a powder made of a metallic material. Such a metallic material may be any material that can be irradiated with a laser to melt it and form a cladding layer, such as a copper alloy.

[0017] Specifically, as shown in FIGS. 2 and 3, metal powder is supplied to the workpiece W10. Then, a first metal powder layer PL1 is formed on the workpiece W10. The first metal powder layer PL1 is made of the metal powder. FIG. 2 is a diagram showing the area where the buildup layer is formed in an example of a method for manufacturing a buildup layer according to the first embodiment. FIG. 3 is a schematic cross-sectional view showing a laser irradiated portion at the start of laser irradiation in an example of a welding method according to the first embodiment. The workpiece W10 is made of, for example, pure aluminum or an aluminum alloy. An example of the workpiece W10 shown in FIG. 2 is an engine cylinder head having a valve seat W1. The valve seat W1 is a region extending in an annular shape around a center WO. In this example, the buildup layer is formed over the entire valve seat W1. Specifically, first, metal powder is supplied to a processing start position W1A of the valve seat W1 of the workpiece W10.

[0018] In steps ST1 to ST7, which will be described later, the location where the metal powder is supplied is moved from the processing start position W1A along the processing direction W1B (here, clockwise as viewed in FIG. 2). Specifically, the location where the metal powder is supplied starts from the processing start position W1A, passes through the processing end position W1C, and then goes around the valve seat W1 once, that is, returns to the processing start position W1A. The location where the metal powder is supplied is then moved, passes through the processing start position W1A, and reaches the processing end position W1C again. In steps ST1 to ST7, which will be described later, the metal powder continues to be supplied while the location where the metal powder is supplied starts from the processing start position W1A and reaches the processing end position W1C again.

[0019] Next, the shape of the metal powder layer is measured from the start of the metal powder supply until a predetermined period of time has elapsed (step ST2). Specifically, as shown in FIG. 4, from the start time t0 when the metal powder supply starts until the target value achievement time t1 when the supply rate of the metal powder reaches the target value PF1, a first metal powder layer PL1 is formed on the valve seat W1 of the workpiece W10 as shown in FIG. 3. FIG. 4 is a graph showing the flow rate of the metal powder with respect to time in an example of the welding method according to the first embodiment. For example, the shape of the first metal powder layer PL1 may be measured using a laser displacement sensor. Alternatively, the shape of the first metal powder layer PL1 may be calculated from the sum of the flow rates of the metal powder from the start time t0 to the target value achievement time t1 shown in FIG. 4. Alternatively, the shape of the first metal powder layer PL1 may be calculated by calculating the amount of light blocked using two photoelectric sensors. The two photoelectric sensors are respectively provided at positions on the valve seat W1 shown in FIG. 2, sandwiching the processing point therebetween and spaced apart by the same distance.

[0020] Next, as shown in FIG. 3, a first laser irradiation range L1 is set to a range corresponding to the shape of the first metal powder layer PL1 (step ST3). As shown in FIG. 4, the amount of metal powder supplied from the start time t0 to the target value achievement time t1 is smaller than the amount of metal powder supplied after the target value achievement time t1. Therefore, as shown in FIG. 5A, the laser irradiation range on the irradiated surface IS is set to the first irradiation range L1. FIG. 5A is a schematic diagram showing the laser irradiation range on the laser irradiated surface at the start of laser irradiation in an example of the welding method according to the first embodiment. The first irradiation range L1 may be smaller than a second irradiation range L2 described later, specifically, may have a smaller width.

[0021] Next, the laser begins to be irradiated onto the workpiece W10 shown in Figures 2 and 3 (step ST4). Because the first irradiation range L1 is a range corresponding to the shape of the first metal powder layer PL1, all of the irradiated laser may be irradiated onto the first metal powder layer PL1. If all of the laser is irradiated onto the metal powder layer, the workpiece W10, which is the base material, is not irradiated with the laser and is not affected by the heat from the laser welding. Therefore, good welding quality can be ensured. Note that the laser continues to be irradiated onto the workpiece W10 from step ST4 to step ST7.

[0022] Next, the shape of the metal powder layer is measured again at a time point a predetermined time has elapsed since the start time t0 shown in FIG. 4 (step ST5). Specifically, at a time point after the target value achievement time t1, as shown in FIG. 6, a second metal powder layer PL2 is formed on the valve seat W1 of the workpiece W10. FIG. 6 is a schematic cross-sectional view showing a laser irradiated portion after a predetermined time has elapsed since the start of laser irradiation in an example of the welding method according to embodiment 1. Also, as in step ST2, the shape of the second metal powder layer PL2 may be obtained by using the laser displacement meter described above, calculating the total amount of powder flow from the start time t0 (see FIG. 3) described above to a time point after the target value achievement time t1, or calculating the amount of light blocking using the two photoelectric sensors described above.

[0023] Next, the second laser irradiation range L2 is reset to a range corresponding to the shape of the second metal powder layer PL2 (step ST6). As shown in FIG. 5B, the laser irradiation range on the irradiated surface IS is set to the second irradiation range L2, which is a range corresponding to the shape of the second metal powder layer PL2. FIG. 5B is a schematic diagram showing the laser irradiation range on the laser irradiated surface after a predetermined time has elapsed since the start of laser irradiation in an example of the welding method according to embodiment 1. As shown in FIG. 4, the amount of metal powder supplied from the start time t0 to the target value achievement time t1 is greater than the amount of metal powder supplied from the start time t0 to the target value achievement time t1. Therefore, the second metal powder layer PL2 is larger than the first metal powder layer PL1. Furthermore, the second irradiation range L2 is larger than the first irradiation range L1 described above.

[0024] Finally, the laser is irradiated onto the reset irradiation range on the workpiece W10 (step ST7). Because the second irradiation range L2 shown in FIG. 6 corresponds to the shape of the second metal powder layer PL2, all of the irradiated laser may be irradiated onto the second metal powder layer PL2. When the laser is irradiated, a buildup layer is formed on the workpiece W10. Simultaneously with this laser irradiation, metal powder is continued to be supplied until the area where metal powder is being supplied reaches the processing end position W1C shown in FIG. 2 again. This allows a buildup layer to be formed over the entire valve seat W1 of the workpiece W10.

[0025] As described above, according to the method for manufacturing a buildup layer according to the first embodiment, the laser can be irradiated to an irradiation range that corresponds to the shape of the metal powder layer. Therefore, even if the shape of the metal powder layer changes significantly, the entire laser can be irradiated onto the metal powder layer. In other words, the laser can be appropriately irradiated onto the metal powder layer. Therefore, the workpiece W10, which is the base material, is not irradiated with the laser and is not thermally affected by the laser. Therefore, the occurrence of weld cracks can be suppressed. Furthermore, good welding quality can be ensured.

[0026] In step ST7, the second irradiation range L2 may be acquired in advance. If the second irradiation range L2 is acquired in advance, after step ST4 is performed, steps ST5 and ST6 may be omitted and step ST7 may be performed. The second irradiation range L2 acquired in advance is larger than the first irradiation range L1 described above.

[0027] The present invention is not limited to the above-described embodiment, and can be appropriately modified without departing from the spirit and scope of the present invention. Furthermore, the present invention may be implemented by appropriately combining the above-described embodiment and examples thereof. [Explanation of symbols]

[0028] W10 Work W1 valve seat W1A Machining start position W1B Machining direction W1C Machining end position WO center PL1 First metal powder layer PL2 Second powdered metal layer IS irradiated surface L1 First illumination range L2 Second illumination range ST1, ST2, ST3, ST4, ST5, ST6, ST7 steps PF1 target value Start time of t0 t1 target value achieved

Claims

1. A method for manufacturing a build-up layer, comprising: supplying a metal powder to a workpiece to form a metal powder layer made of the metal powder; and irradiating the metal powder layer with a laser to form a build-up layer on the workpiece, measuring the shape of the metal powder layer from the start of supplying the metal powder until a predetermined period of time has elapsed; and setting the laser irradiation range to a range corresponding to the shape of the metal powder layer, In the step of measuring the shape of the metal powder layer, the time when the predetermined period has elapsed is the time when the supply amount of the metal powder has reached a target value. Method for manufacturing the build-up layer.

2. and after the supply amount of the metal powder reaches a target value, resetting the laser irradiation range to a range larger than the range according to the shape of the metal powder layer. The method for manufacturing the build-up layer according to claim 1.

3. measuring the shape of the metal powder layer again after the supply rate of the metal powder reaches a target value; and resetting the laser irradiation range to a range according to the shape of the metal powder layer measured again. The method for manufacturing the build-up layer according to claim 1.

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