JPH0482601A - Cutting work of thermally sprayed coat - Google Patents

Abstract

PURPOSE:To reduce abrasion of a machine tool, further to remove pores while making the inside of coats in an irradiated area very dense and also to eliminate any defect such as cracks by carrying out a cutting work on a thermally sprayed shaft while radiating a laser beam thereon. CONSTITUTION:A laser beam 1 emitted from a light source in a working head 7 is condensed through lenses, and a re-melted area 6 is formed on a thermally sprayed shaft 3, and pores are removed from layers inside of coats, and the inside of the coats is made very dense and cooled rapidly. And a part of the area 6 re-melted by rotation of the thermally sprayed shaft 3 is cut by a chip 4 such as CBN so that working can be carried out at a very high speed under a condition close to that for working steel. And abrasion of a machine tool is reduced, and the inside of coats is made very dense, and any defect such as cracks can not be created.

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Field of Application] The present invention relates to a cutting method for finishing a thermal spray coating.

[Prior Art] Conventionally, as a finishing method for a coating thermally sprayed on a shaft, a so-called thermal spray coating, polishing has been performed because the thermal spray coating itself is very hard. However, in recent years, cutting methods have been attempted in order to improve processing efficiency.

[Problem to be solved by the invention] However, when cutting, C used as a tool
BN tools and ceramic tools are prone to wear and chipping. In addition, the processed film also had a tendency to develop cracks. Furthermore, pores are often present in the sprayed coating, which poses problems in terms of corrosion resistance.

The present invention was made in order to solve the above-mentioned problems, and aims to provide a method for cutting a thermal sprayed coating, which reduces tool wear and eliminates pores in the coating. .

[Means for Solving the Problems] In order to achieve this object, the thermal sprayed coating cutting method of the present invention performs cutting while irradiating the surface of the coating to be cut with a laser beam.

[Function] In the thermal spray coating cutting method of the present invention having the above-described configuration, by irradiating the coating surface with a laser beam, the coating surface is locally remelted, and in a state where it is not yet completely solidified, Process the film using a cutting tool.

[Example 1] Hereinafter, an example embodying the present invention will be described with reference to the drawings.

First, the configuration of a processing apparatus to which the present invention is applied will be explained with reference to FIGS. 1 and 2.

A tool holder 5 as a machining tool and a tip 4 set therein are provided near the sprayed shaft 3 as a workpiece, and the CO2 laser beam 1 from the machining head 7 is focused on a desired position for machining. is configured to be

In the processing head 7, the lens 2 is set with the O-ring 8 placed below, and is fixed from above with a fixing screw 9. A laser beam 1 emitted from a light source provided at a position (not shown) is focused by a lens 2, and the spot diameter at the processing position is changed by moving the processing head 7 up and down.

Now, spot diameter 2 at positions A, B, and C in Figure 2.
FIG. 3 shows the temperature rise changes when an alumina thermal spray coating is irradiated with a laser power of 800 watts for sizes of mm, 4 mm, and 6 mm.

As shown in the figure, the degree of increase varies greatly depending on the spot diameter. In this example, the surface of the sprayed coating was irradiated with laser beam 1 with a spot diameter of 2 mm.

When irradiated with a laser, a remelted region 6 is formed on the shaft 3. Then, the pores in the layer inside the film are removed and the layer is reduced to several layers, and is rapidly cooled. Then, the part of the region 6 that is remelted by rotating the sprayed shaft 3 is made of CBN.
It is cut by the tip 4 of. The processing conditions are: peripheral speed 1mm/m1n1 chip feed 2mm, depth of cut 0.3
mm. It can be seen that these machining conditions are close to those used when machining steel, and that machining can be performed at extremely high speeds.

As is clear from the detailed description above, according to the method of cutting a thermal sprayed coating of this embodiment, the laser beam 1 is irradiated to the sprayed shaft 3 for cutting, thereby reducing tool wear. In addition, the irradiated area inside the film is reduced in number, and there are no pores and defects such as cracks do not occur.

Note that the present invention is not limited to the embodiments described above, and various changes can be made without departing from the spirit thereof.

[Effects of the Invention] As is clear from the detailed description above, according to the method for cutting a thermally sprayed coating of the present invention, the tool can be The wear of the coating is reduced, and the interior of the coating in the irradiated area is reduced in number, eliminating voids and causing no defects such as clutter.

[Brief explanation of the drawing]

Figures 1 to 3 show examples embodying the present invention. Figure 1 is an explanatory diagram showing the state of cutting in this example, and Figure 2 is an illustration of a laser beam focused by a lens. FIG. 3 is an explanatory diagram showing the laser beam irradiation time and temperature change on the alumina film at position ABC in FIG. 2. In the figure, 1 is a laser beam and 3 is an axis. Third mother! Entaku I7P^()・Power 1st evil 2nd figure

Claims (1)

[Claims] 1. In the cutting method that cuts the coating that has been thermally sprayed on the shaft, while irradiating the surface of the coating to be cut with a laser beam,
A method for cutting a thermal spray coating, which is characterized by cutting.