# US 2019/0168454 A1 · Laser Additive Manufacturing Apparatus and Laser Additive Manufacturing Method

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- Number: US 2019/0168454 A1
- Document ID: US20190168454A1
- Status: Published application
- Kind: A1
- Application number: 16/204,221
- Filed: 2018-11-29
- Published: 2019-06-06
- Earliest claimed: 2017-12-04
- Assignees: Dmg Mori Co., Ltd.
- Applicants: DMG MORI Company Limited
- Inventors: Masaki Kondo
- Web page: https://patentgrep.com/patent/US20190168454A1

## CPC

- B29C 64/268: using laser beams; using electron beams [EB]
- B22F 10/00: Additive manufacturing of workpieces or articles from metallic powder (apparatus or devices therefor B22F12/00)
- B22F 10/25: Direct deposition of metal particles, e.g. direct metal deposition [DMD] or laser engineered net shaping [LENS]
- B22F 12/224: {for motion along a direction within the plane of a layer}
- B22F 12/44: characterised by the configuration of the radiation means
- B22F 12/49: Scanners
- B33Y 10/00: Processes of additive manufacturing
- B33Y 30/00: Apparatus for additive manufacturing; Details thereof or accessories therefor
- G02B 26/10: Scanning systems
- G02B 27/0944: {Diffractive optical elements, e.g. gratings, holograms (gratings per se G02B5/18; holograms used as optical elements per se G02B5/32)}
- G02B 27/0955: {Lenses (lenses per se G02B3/00)}
- G02B 27/30: Collimators
- B22F 10/32: of the atmosphere, e.g. composition or pressure in a building chamber
- B22F 12/53: Nozzles
- B29C 64/153: using layers of powder being selectively joined, e.g. by selective laser sintering or melting
- B29C 64/286: Optical filters, e.g. masks
- Y02P 10/25: Process efficiency
- B29C: SHAPING OR JOINING OF PLASTICS; SHAPING OF MATERIAL IN A PLASTIC STATE, NOT OTHERWISE PROVIDED FOR; AFTER-TREATMENT OF THE SHAPED PRODUCTS, e.g. REPAIRING (making preforms B29B11/00; making laminated products by combining previously unconnected layers which become one product whose layers will remain together B32B37/00 - B32B41/00)
- B22F: WORKING METALLIC POWDER; MANUFACTURE OF ARTICLES FROM METALLIC POWDER; MAKING METALLIC POWDER (making alloys by powder metallurgy C22C); APPARATUS OR DEVICES SPECIALLY ADAPTED FOR METALLIC POWDER
- B33Y: ADDITIVE MANUFACTURING, i.e. MANUFACTURING OF THREE-DIMENSIONAL [3D] OBJECTS BY ADDITIVE DEPOSITION, ADDITIVE AGGLOMERATION OR ADDITIVE LAYERING, e.g. BY 3D PRINTING, STEREOLITHOGRAPHY OR SELECTIVE LASER SINTERING
- G02B: OPTICAL ELEMENTS, SYSTEMS OR APPARATUS
- Y02P: CLIMATE CHANGE MITIGATION TECHNOLOGIES IN THE PRODUCTION OR PROCESSING OF GOODS

## Abstract

A laser additive manufacturing apparatus and a method thereof are provided. The apparatus includes an irradiation unit that irradiates an irradiation region with a laser beam having a light intensity distribution converted by a diffractive optical element, a head having a material supplying unit for supplying powder material to the irradiation region, and a movement mechanism which relatively moves the head and a workpiece. In the irradiation region, irradiation light forms a substantially circular spot having a light intensity distribution in which light intensity in an outer peripheral portion is higher than light intensity in a central portion, and the central portion has predetermined light intensity, and the material supplying unit supplies the powder material to the substantially circular spot.

## Claims

### Claim 1

A laser additive manufacturing apparatus comprising:
an irradiation unit that irradiates an irradiation region with a laser beam having a light intensity distribution converted by a diffractive optical element;
a head having a material supplying unit for supplying powder material to the irradiation region; and
a movement mechanism which relatively moves the head and a workpiece,
wherein in the irradiation region, irradiation light forms a substantially circular spot having a light intensity distribution in which light intensity in an outer peripheral portion is higher than light intensity in a central portion, and the central portion has predetermined light intensity, and
the material supplying unit supplies the powder material to the substantially circular spot.

### Claim 2 (depends on 1)

The laser additive manufacturing apparatus according to claim 1, wherein a light intensity distribution is formed such that the light intensity in the central portion is 10% or more and 30% or less of the light intensity in the outer peripheral portion.

### Claim 3 (depends on 1)

The laser additive manufacturing apparatus according to claim 1, wherein
the irradiation unit includes a collimate lens for receiving a laser beam transmitted from an optical fiber to emit parallel light to the diffractive optical element,
the diffractive optical element has a diffraction grating pattern for forming a light intensity distribution of a top-hat type, and
a light diameter of light to be emitted from the collimate lens is set larger than an outer diameter of an incident surface of the diffractive optical element, to form the light intensity distribution in which the light intensity in the outer peripheral portion is higher than the light intensity in the central portion, and the central portion has predetermined light intensity.

### Claim 4 (depends on 3)

The laser additive manufacturing apparatus according to claim 3, wherein the collimate lens is moved in an optical axis direction to change a profile of the light intensity distribution.

### Claim 5 (depends on 3)

The laser additive manufacturing apparatus according to claim 3, wherein an optical axis of the collimate lens is inclined from a normal direction of the incident surface of the diffractive optical element to form the light intensity distribution asymmetric to the optical axis.

### Claim 6

A laser additive manufacturing method comprising:
causing a laser beam to enter a diffractive optical element;
irradiating an irradiation region by emitting from a head a laser beam having a light intensity distribution converted by the diffractive optical element;
supplying powder material to the irradiation region from the head; and
relatively moving the head and a workpiece,
wherein in the irradiation region, irradiation light forms a substantially circular spot having a light intensity distribution in which light intensity in an outer peripheral portion is higher than light intensity in a central portion, and the central portion has predetermined light intensity, and
the powder material is supplied to the substantially circular spot from the head.

### Claim 7 (depends on 2)

The laser additive manufacturing apparatus according to claim 2, wherein
the irradiation unit includes a collimate lens for receiving a laser beam transmitted from an optical fiber to emit parallel light to the diffractive optical element,
the diffractive optical element has a diffraction grating pattern for forming a light intensity distribution of a top-hat type, and
a light diameter of light to be emitted from the collimate lens is set larger than an outer diameter of an incident surface of the diffractive optical element, to form the light intensity distribution in which the light intensity in the outer peripheral portion is higher than the light intensity in the central portion, and the central portion has predetermined light intensity.

### Claim 8 (depends on 4)

The laser additive manufacturing apparatus according to claim 4, wherein an optical axis of the collimate lens is inclined from a normal direction of the incident surface of the diffractive optical element to form the light intensity distribution asymmetric to the optical axis.