JPS5890391A - Oblique hole working method by laser - Google Patents

Abstract

PURPOSE:To pierce a hole on a work by a laser beam of relatively low energy density by performing surface treatment that heightens absorption of a laser beam on the surface of a work and irradiating a laser beam at large angles of incidence of specified range. CONSTITUTION:Metallic particles of Ni etc. are jetted to the condensing part with high pressure gas sent from a pressure gas source to form deposition 7 of metallic particles 5 on the surface of working. At the same time, or after that, a laser beam is irradiated onto the surface of the work 1 at angles theta of incidence of 45-75 deg.. Since the surface of the work 1 is roughened by the deposition 7, the laser beam L is absorbed effectively, and piercing can be started in the direction of incident beam even when the laser beam L is low in energy density.

Description

DETAILED DESCRIPTION OF THE INVENTION The invention in the technical field
Regarding the processing method for drilling diagonal holes.

TECHNICAL BACKGROUND OF THE INVENTION Metal objects used at high temperatures of more than 100 degrees Celsius are naturally made of heat-resistant and desirable metal materials. However, K, which is used for long periods of time under such high temperatures, has limitations due to its material properties, and it is considered to add a means of protecting the object from thermal effects by forced cooling using liquid cooling or air cooling. It is being In the case of ζ, many relatively small holes are formed in the object to allow cooling liquid and air to pass through. If the hole-expanded object has a complicated shape, diagonal holes with different angles and degrees are used for cooling efficiency.

It is being considered to use laser light to make diagonal holes like ζ.

Problems with the Background Art Because the hole is made of heat-resistant material and the hole is drilled diagonally, the surface from which the hole starts to be machined is irradiated with a high-density laser pulse. However, when high-density pulses are continuously drilled, it is difficult to obtain a medium-thick hole or a straight hole.

Particularly for holes that are inclined at an angle of incidence of 45° or more, if the drilling is continued to the inside using the optimum density of the laser condensing part required for processing the entrance part of the hole, there is a drawback that the inside of the hole will not be thick. Ta.

The invention of Object of the Invention ζ was made in view of the above points, and the processing
To provide a laser machining method capable of machining a straight oblique hole even if the incident angle of the laser beam changes.

Summary of the invention A surface treatment that increases the absorption of laser light is applied to the processed surface at the same time or before laser irradiation, and uniform processing is performed from the surface of the hole to the inside of the hole, which reduces the absorption of laser light with relatively weak energy. Natsumei-wel is made by cutting a diagonally large hole to form a groove.

Embodiment of the Invention The figure shows an embodiment of the invention which increases the absorption of laser light.
As an intermediate treatment, a mode is shown in which holes are formed while forming a metal film such as chromium in nickel, which absorbs laser light with a liquid length of 1.06 μm relatively well. That is, (1) is a workpiece which is supported with its machined surface oriented at a predetermined angle 111EK with respect to the axis (2)K of the laser beam (L). (3) is a condensing lens, and (4) is a nozzle directed toward the laser beam (L) condensing section. From this nozzle (4), metal particles (5) such as nickel are injected into the light condensing section together with the high pressure gas sent from the pressure gas Ii [(6).

In the drilling process, a laser beam (L) is irradiated at the same time as the metal particles (5) are ejected to form deposits* (7) of the metal particles (5) on the processed surface. After that, preferably the injection of the metal powder (5) is stopped and the irradiation of the laser beam (L) is continued. Since the surface of the deposit (7) K is rough, the laser beam (L) is effectively absorbed. As a result, the laser beam (L) is applied to the surface of the workpiece (1).
Under conditions where the incident angle is large between 45° and 85° and 11°, when drilling is started, the Q condensed spot ＼ Even with low energy density, drilling is performed on the surface of the inclined workpiece (1) in the direction of the incident beam. You can start. By forming nine hole entrances on the surface with an inclined incident surface in this way, the laser beam (L) is well absorbed by the holes, and the laser beam (L) is well absorbed by the holes. (L) that t
If the irradiation is continued, the laser light is effectively absorbed sufficiently inside the hole, so that a straight hole (8) with no thickness in the workpiece (1) is formed.

In addition, in the above embodiment, metal powder is sprayed on the processed surface, but in addition to the metal powder, particles of synthetic resin containing aluminum oxide, carbon powder, etc. may be sprayed. In addition to the above, an active gas such as oxygen gas may be directly sprayed onto the processing surface to form an oxide film before proceeding to the drilling process. Furthermore, each of the above surface treatments may be performed simultaneously with the laser processing, or may be performed before the start of irradiation of the laser processing. Instead of depositing particles of metal or the like onto the processed surface using a laser beam, the particles may simply be attached to the processed surface using a binder in advance.

Effects of the Invention Since it is possible to start machining a hole with a large incident angle on the surface of the workpiece using a laser beam with a relatively low energy density and form the entrance of the hole, a straight and diagonal large hole with no middle thickness can be obtained. As a result, if a large number of diagonal holes are required for cooling, the number of diagonal holes in the unit hole can be increased, improving cooling efficiency. t4, straight. The hole formation also has the effect of not lowering the aggregate strength of the workpiece more than necessary.

[Brief explanation of the drawing]

The drawings are processing mode diagrams for explaining one embodiment of the present invention. (1)...Processed product (5)...Metal powder (7)...Deposit agent Patent attorney Kensuke Norichika (and one other person)

Claims (1)

[Claims] A step of irradiating the surface of the workpiece with a laser beam at an angle of incidence of 45'' to 75'' on the processed surface to increase the absorption of the laser beam, and a step of applying a laser beam to the surface-treated processed surface. A laser diagonal hole machining method characterized by comprising a step of irradiating light.